epiglucan and Candidiasis

Early diagnosis and prompt initiation of appropriate antimicrobial therapy are crucial steps in the management of patients with invasive fungal infections. However, the diagnosis of invasive mycoses remains a major challenge in clinical practice, because presenting symptoms may be subtle and non-invasive diagnostic assays often lack sensitivity and specificity. Diagnosis is often expressed on a scale of probability (proven, probable and possible) based on a constellation of imaging findings, microbiological tools and histopathology, as there is no stand-alone assay for diagnosis. Recent data suggest that the carbohydrate biomarker (1→3)-β-d-glucan may be useful in both the diagnosis and therapeutic monitoring of invasive fungal infections due to some yeasts, molds, and dimorphic fungi. In this paper, we review recent advances in the use of (1→3)-β-d-glucan to monitor clinical response to antifungal therapy and explore how this assay may be used in the future.

Topics: Animals; Antifungal Agents; Aspergillosis; beta-Glucans; Bronchoalveolar Lavage Fluid; Candidiasis; Humans; Invasive Fungal Infections; Meningitis, Fungal; Pneumonia, Pneumocystis

Invasive fungal diseases are important clinical problems that are often complicated by severe illness and therefore the inability to use invasive measures to definitively diagnose the disease. Tests for a range of fungal biomarkers that do not require an invasive sample-collection procedure have been incorporated into adult clinical practice, but pediatric data and pediatric-specific recommendations for some of these diagnostic tools are lacking. In this review, we summarize the published literature and contemporary strategies for using the biomarkers galactomannan, (1→3)-β-d-glucan, Candida mannan antigen and anti-mannan antibody, and fungal polymerase chain reaction for diagnosing invasive fungal disease in children. Data on biomarker use in neonates and children with cancer, history of hematopoietic stem cell transplant, or primary immunodeficiency are included. Fungal biomarker tests performed on blood, other body fluids, or tissue specimens represent promising adjuncts to the diagnostic armamentarium in populations with a high prevalence of invasive fungal disease, but substantial gaps exist in the correct use and interpretation of these diagnostic tools in pediatric patients.

Topics: Antibodies, Fungal; Antigens, Fungal; Aspergillosis; Aspergillus; beta-Glucans; Biomarkers; Candida; Candidiasis; Child; DNA, Fungal; Galactose; Humans; Immunoassay; Invasive Fungal Infections; Mannans; Polymerase Chain Reaction

Candida albicans is a common human pathogen. Occasionally, it can cause peritonitis in immunocompromised and postsurgical patients. We report a case of a male patient who presented with abdominal pain and distention. He had a history of end-stage liver disease secondary to alcoholism. His peritoneal fluid culture revealed C albicans, and (1-3)-β-d glucan (BDG) level was elevated. His hospital course was complicated by sepsis and renal failure. He was treated with antifungals for spontaneous fungal peritonitis. Fungal peritonitis should be suspected in patients with chronic liver disease particularly with elevated BDG levels.

Topics: beta-Glucans; Candida albicans; Candidiasis; Humans; Liver Cirrhosis, Alcoholic; Male; Middle Aged; Peritonitis; Proteoglycans

Fungal infections due to Candida and Aspergillus species cause extensive morbidity and mortality, especially among immunosuppressed patients, and antifungal therapy is critical to patient management. Yet only a few drug classes are available to treat invasive fungal diseases, and this problem is compounded by the emergence of antifungal resistance. Echinocandin drugs are the preferred choice to treat candidiasis. They are the first cell wall-active agents and target the fungal-specific enzyme glucan synthase, which catalyzes the biosynthesis of β-1,3-glucan, a key cell wall polymer. Therapeutic failures occur rarely among common Candida species, with the exception of Candida glabrata, which is frequently multidrug resistant. Echinocandin resistance in susceptible species is always acquired during therapy. The mechanism of resistance involves amino acid changes in hot-spot regions of Fks subunits of glucan synthase, which decrease the sensitivity of the enzyme to drug. Cellular stress response pathways lead to drug adaptation, which promotes the formation of resistant fks strains. Clinical factors promoting echinocandin resistance include empiric therapy, prophylaxis, gastrointestinal reservoirs, and intra-abdominal infections. A better understanding of the echinocandin-resistance mechanism, along with cellular and clinical factors promoting resistance, will facilitate more effective strategies to overcome and prevent echinocandin resistance.

Topics: Antifungal Agents; beta-Glucans; Candida albicans; Candida glabrata; Candidiasis; Drug Resistance, Fungal; Echinocandins; Glucosyltransferases; Humans; Species Specificity

The biomarkers galactomannan and 1,3-β-d-glucan have been well studied over the past years and are gaining a role in the diagnosis of invasive fungal infections. Although not as well studied until recently, molecular methods for the diagnosis of invasive fungal infection are also being evaluated. Outcomes data for molecular testing are expanding, but have not yet provided enough evidence for inclusion of molecular diagnostics in formal clinical guidelines. Lack of standardization and validation of the various molecular assays and platforms has hindered their widespread acceptance in the evaluation of invasive fungal infections, although the future is promising.

Topics: Aspergillosis; beta-Glucans; Biomarkers; Bronchoalveolar Lavage Fluid; Candidiasis; False Positive Reactions; Galactose; Humans; Mannans; Pathology, Molecular; Polymerase Chain Reaction; Predictive Value of Tests; Sugar Alcohols

The echinocandins are antifungal agents, which act by inhibiting the synthesis of β-(1,3)-D-glucan, an integral component of fungal cell walls. Caspofungin, the first approved echinocandin, demonstrates good in vitro and in vivo activity against a range of Candida species and is an alternative therapy for Aspergillus infections. Caspofungin provides an excellent safety profile and is therefore favoured in patients with moderately severe to severe illness, recent azole exposure and in those who are at high risk of infections due to Candida glabrata or Candida krusei. In vivo/in vitro resistance to caspofungin and breakthrough infections in patients receiving this agent have been reported for Candida and Aspergillus species. The types of pathogens and the frequency causing breakthrough mycoses are not well delineated. Caspofungin resistance resulting in clinical failure has been linked to mutations in the Fksp subunit of glucan synthase complex. European Committee for Antimicrobial Susceptibility Testing and Clinical and Laboratory Standards Institute need to improve the in vitro susceptibility testing methods to detect fks hot spot mutants. Caspofungin represents a significant advance in the care of patients with serious fungal infections.

Topics: Antifungal Agents; Aspergillosis; Aspergillus; beta-Glucans; Biofilms; Candida; Candidiasis; Caspofungin; Cell Wall; Clinical Trials as Topic; Drug Resistance, Fungal; Echinocandins; Glucosyltransferases; Guidelines as Topic; Humans; Lipopeptides; Proteoglycans

Invasive fungal infections (IFIs) are difficult to diagnose, especially early in the course of infection when antifungal therapy is most effective. There are two commercially available biomarker assays useful for detection of the IFIs most commonly seen in patients with hematologic malignancies, the galactomannan and beta glucan assays. The former is specific for aspergillosis, the latter positive for not only Aspergillus and Candida species, but several other clinically relevant fungal pathogens as well. Both have good assay performance characteristics, provide rapid test results, are widely available, can be assayed non-invasively, and are positive early in the course of infection, often before onset of signs and symptoms of infection. Adoption of these assays into clinical practice has led to reduced need to perform invasive procedures to obtain deep tissue to establish the diagnosis of invasive fungal infections. Improved survival rates from aspergillosis are, in part, due to earlier detection of infection and earlier therapy.

Topics: Acute Disease; Aspergillosis; Aspergillus; beta-Glucans; Biomarkers; Candida; Candidiasis; Galactose; Hematopoietic Stem Cell Transplantation; Humans; Leukemia; Mannans; Transplantation, Homologous

As a principle receptor to β-glucan in the Candida albicans cell wall, Dectin-1 performs recognition specifically and its mechanisms are diverse in different situations. With a view to developing certain antifungal targeted drugs, this review provides new insights into the novel immune signaling pathways induced by Dectin-1, especially the novel understandings of CARD9 in the Syk-dependent NF-κB pathway, and of Raf-1 in the Syk-independent NF-κB signaling pathway.

Topics: Animals; beta-Glucans; Candida albicans; Candidiasis; CARD Signaling Adaptor Proteins; Humans; Intracellular Signaling Peptides and Proteins; Lectins, C-Type; Membrane Proteins; Mice; Nerve Tissue Proteins; NF-kappa B; Protein-Tyrosine Kinases; Proto-Oncogene Proteins c-raf; Saccharomyces cerevisiae; Signal Transduction; Syk Kinase

The CLSI established clinical breakpoints (CBPs) for caspofungin (CSF), micafungin (MCF) and anidulafungin (ANF) versus Candida. The same CBP (susceptible (S): MIC ≤ 2 mcg/ml; non-S: MIC > 2 mcg/ml) was applied to all echinocandins and species. More data now allow reassessment of these CBPs. We examined cases of echinocandin failure where both MICs and fks mutations were assessed; wild type (WT) MICs and epidemiological cutoff values (ECVs) for a large Candida collection; molecular analysis of fks hotspots for Candida with known MICs; and pharmacokinetic and pharmacodynamic (PK/PD) data. We applied these findings to propose new species-specific CBPs for echinocandins and Candida. Of 18 candidiasis cases refractory to echinocandins and with fks mutations, 28% (CSF), 58% (ANF) and 66% (MCF) had MICs in the S category using CBP of ≤ 2 mcg/ml, while 0-8% would be S using CBP of ≤ 0.25 mcg/ml. WT MIC distributions revealed ECV ranges of 0.03-0.25 mcg/ml for all major species except C. parapsilosis (1-4 mcg/ml) and C. guilliermondii (4-16 mcg/ml). Among Candida tested for fks mutations, only 15.7-45.1% of 51 mutants were detected using the CBP for NS of >2 mcg/ml. In contrast, a cutoff of >0.25 mcg/ml for C. albicans, C. tropicalis, C. krusei, and C. dubliniensis detected 85.6% (MCF) to 95.2% (CSF) of 21 mutant strains. Likewise, a cutoff of >0.12 mcg/ml for ANF and CSF and of >0.06 mcg/ml for MCF detected 93% (ANF) to 97% (CSF, MCF) of 30 mutant strains of C. glabrata. These data, combined with PK/PD considerations, support CBPs of ≤ 0.25 mcg/ml (S), 0.5 mcg/ml (I), ≥ 1 (R) for CSF/MCF/ANF and C. albicans, C. tropicalis and C. krusei and ≤ 2 mcg/ml (S), 4 mcg/ml (I), and ≥ 8 mcg/ml (R) for these agents and C. parapsilosis. The CBPs for ANF and CSF and C. glabrata are ≤ 0.12 mcg/ml (S), 0.25 mcg/ml (I), and ≥ 0.5 mcg/ml (R), whereas those for MCF are ≤ 0.06 mcg/ml (S), 0.12 mcg/ml (I), and ≥ 0.25 mcg/ml (R). New, species-specific CBPs for Candida and the echinocandins are more sensitive to detect emerging resistance associated with fks mutations, and better able to predict risk for clinical failure.

Topics: Anidulafungin; Antifungal Agents; beta-Glucans; Candida; Candidiasis; Caspofungin; Drug Resistance, Fungal; Echinocandins; Fluconazole; Glucosyltransferases; Humans; Inhibitory Concentration 50; Lipopeptides; Micafungin; Microbial Sensitivity Tests; Mutation; Proteoglycans; Randomized Controlled Trials as Topic; Species Specificity; Treatment Outcome

Fungal infections are of great relevance in surgical intensive care and Candida species represent the predominant part of fungal pathogens. Invasive aspergillosis is also relevant especially in patients with chronic pulmonary diseases. It is crucial for therapy success to begin adequate antifungal treatment at an early stage of the disease. Risk stratification of individual patient symptoms is essential for therapy timing. In case of suspected or proven candida infection, fluconazole is the agent of choice when the patient is clinically stable and no azoles have been administrated in advance and the local epidemiology makes azol resistance unlikely. For clinically instable patients with organ dysfunction the echinocandins serve as primary therapy because of their broad spectrum and reasonable safety profile. Due to a relevant proportion of azole resistant Candida species, susceptibility testing should be done routinely. Depending on the species detected de-escalating to an azole is feasible if organ dysfunctions have resolved. An invasive aspergillosis is primarily treated with voriconazole.

Topics: Adjuvants, Immunologic; Antifungal Agents; Azoles; beta-Glucans; Candidiasis; Critical Care; Cryptococcosis; Echinocandins; Galactose; Humans; Mannans; Mucus; Mycoses; Polyenes; Reverse Transcriptase Polymerase Chain Reaction; Risk Assessment; Tomography, X-Ray Computed

The laboratory diagnosis of invasive candidiasis is based on the demonstration of tissue invasion by Candida, the culture of the fungus in specimens from sterile body sites and the detection of a number of biomarkers including some antibodies, mannan, beta-1,3-D-glucan and Candida DNA.. Description and evaluation of results obtained in published studies on the usefulness of biomarkers in the diagnosis of invasive candidiasis.. A search was performed in the PubMed/Medline database from the National Library of Medicine since January 2000 on the usefulness of biomarkers in the diagnosis of invasive candidiasis. Key words used included candidiasis, Candida, diagnosis, biomarkers, antigen, antibodies, DNA, mannan, and beta-1,3-D-glucan.. Forty one papers dealing with the use of biomarkers in the diagnosis of invasive candidiasis were selected and evaluated, paying special attention to the sensitivity and specificity obtained with the tests used.. Important advances are being reached in the use of biomarkers for the diagnosis of invasive candidiasis, and some of them are being used to start a preemptive therapy strategy.

Topics: Animals; Antibodies, Fungal; beta-Glucans; Biomarkers; Body Fluids; Candida; Candidiasis; DNA, Fungal; False Negative Reactions; False Positive Reactions; Fungemia; Humans; Mannans; Mice; Proteoglycans; Reagent Kits, Diagnostic; Sensitivity and Specificity

Topics: Antifungal Agents; Aspergillosis; beta-Glucans; Biomarkers; Candidiasis; Galactose; Hematologic Diseases; Humans; Immunocompromised Host; Lung Diseases, Fungal; Mannans; Molecular Diagnostic Techniques; Mycoses

Diabetes mellitus (DM) has been considered to predispose to candidiasis. While poor glycemic control increases the risk of superficial candidiasis (especially oral candidiasis), invasive candidiasis is not related to DM. Invasive candidiasis is diagnosed by combination of clinical manifestation, laboratory findings and isolation of Candida spp. Strategy of treatment for invasive candidiasis is consist of prophylactic, empiric and targeted therapy. MCFG, FLCZ and AMPH-B are recommended as first line drugs for invasive candidiasis, and L-AMB, VRCZ, ITCZ are considered as alternative drugs in Japanese guideline.

Topics: Amphotericin B; Antifungal Agents; Antigens, Fungal; beta-Glucans; Biomarkers; Candida; Candidiasis; Diabetes Complications; Echinocandins; Fluconazole; Humans; Lipopeptides; Micafungin; Proteoglycans

In the last few years, major advances in the treatment of transplant recipients, with hemato-oncological diseases or admitted to the intensive care unit, has been accompanied by an increase in classical fungal infections and by the emergence of uncommon fungal infections. Despite the development of new diagnostic techniques such as galactomannan detection and the availability of new antifungal agents, these opportunistic infections continue to pose a diagnostic challenge, prolong length of hospital stay, and increase costs. In addition, mortality from these infections is high. The present chapter provides a brief review of the epidemiology of these infections, diagnostic advances, and the new antifungal agents that have been developed in the last few years.

Topics: Anidulafungin; Antifungal Agents; Aspergillosis; beta-Glucans; Candidiasis; Clinical Trials as Topic; Critical Care; Diabetes Complications; Disease Susceptibility; Echinocandins; Fungemia; Galactose; Hematologic Diseases; Humans; Immunocompromised Host; Mannans; Meta-Analysis as Topic; Mycoses; Neoplasms; Opportunistic Infections

Until recently, the diagnosis of systemic mycoses was mainly based on traditional methods producing late and inconclusive results. Currently used methods of serological diagnostics are generally based on detection of cell wall components of selected pathogenic fungal species--mannoproteins, functioning as a antigenic markers. There are big hopes for adaptation of commercially available assays to detect (1 --> 3)-beta-D-glucan because of the fact that its presence in blood and normally sterile body fluids should lead to initiation of the diagnostic workup of invasive fungal infection. Monitoring (1 --> 3)-beta-D-glucan antigenemia is useful in predicting the therapeutic outcome of patients with invasive aspergillosis and in combination with galactomannan detection to identify false-positive reactions. The simultaneous use of both tests is probably more pertinent for the differentiation between yeast and mould infections.

Topics: Aspergillosis; beta-Glucans; Biomarkers; Candidiasis; False Negative Reactions; False Positive Reactions; Humans; Proteoglycans; Reagent Kits, Diagnostic

Micafungin is a relatively broad-spectrum antifungal agent available for clinical use in the US and Japan. By inhibiting the production of beta-1,3-glucan, an essential fungal cell wall component, micafungin has reduced toxicity to mammalian cells while maintaining potent antifungal activity against many pathogenic fungi including polyene- and azole-resistant isolates. Indeed, micafungin has been shown to be efficacious in the treatment of infections caused by Candida and Aspergillus species in clinical trials without the associated toxicities of amphotericin B formulations and drug interactions that occur with the azoles. In this review, the pharmacology, spectrum of activity, clinical efficacy and safety profile of micafungin are discussed.

Topics: Antifungal Agents; Aspergillosis; Aspergillus; beta-Glucans; Candida; Candidiasis; Drug Interactions; Drug Resistance, Fungal; Echinocandins; Fungi; Humans; Lipopeptides; Lipoproteins; Micafungin; Microbial Sensitivity Tests; Peptides, Cyclic

Invasive fungal infections cause morbidity and mortality in severely ill patients, and limited drug classes restrict treatment choices. The echinocandin drugs are the first new class of antifungal compounds that target the fungal cell wall by blocking beta-1,3-d-glucan synthase. Elevated MIC values with occasional treatment failure have been reported for strains of Candida. Yet, an uncertain correlation exists between clinical failure and elevated MIC values for the echinocandin drugs. Fungi display several adaptive physiological mechanisms that result in elevated MIC values. However, resistance to echinocandin drugs among clinical isolates is associated with amino acid substitutions in two "hot-spot" regions of Fks1, the major subunit of glucan synthase. The mutations, yielding highly elevated MIC values, are genetically dominant and confer cross-resistance to all echinocandin drugs. Prominent Fks1 mutations decrease the sensitivity of glucan synthase for drug by 1000-fold or more, and strains harboring such mutations may require a concomitant increase in drug to reduce fungal organ burdens in animal infection models. The Fks1-mediated resistance mechanism is conserved in a wide variety of Candida spp. and can account for intrinsic reduced susceptibility of certain species. Fks1 mutations confer resistance in both yeasts and moulds suggesting that this mechanism is pervasive in the fungal kingdom.

Topics: Amino Acid Substitution; Antifungal Agents; beta-Glucans; Candida albicans; Candidiasis; Drug Resistance, Fungal; Echinocandins; Glucosyltransferases; Humans; Membrane Proteins; Microbial Sensitivity Tests; Mutation; Mycoses; Saccharomyces cerevisiae Proteins

In the last years, the main advances in the serological diagnosis of mycoses caused by yeasts have occurred in the area of antibody and (1-3)-beta-D-glucan detection. Commercialization of the Candida albicans IFA IgG test and detection of antibodies against recombinant antigens Hwp1 and enolase are the most important contributions to the first area. Detection of (1-3)-beta-D-glucan confirms its usefulness as a good marker for the diagnosis of invasive candidiasis. The most recent studies suggest that combination of two tests to detect antígen, antibodies, (1-3)-beta-D-glucan and DNA will be needed to optimize the diagnosis of systemic yeast infections.

Topics: Antibodies, Fungal; Antigens, Fungal; beta-Glucans; Biomarkers; Candida albicans; Candidiasis; DNA, Fungal; Early Diagnosis; Fungemia; Humans; Mycoses; Proteoglycans; Yeasts

Topics: Anidulafungin; Antifungal Agents; beta-Glucans; Candida; Candidiasis; Caspofungin; Cross Infection; Echinocandins; Fungemia; Humans; Infusions, Intravenous; Lipopeptides; Lipoproteins; Male; Micafungin; Microbial Sensitivity Tests; Middle Aged; Neutropenia; Peptides, Cyclic; Practice Guidelines as Topic

Micafungin is a new drug in the echinocandin class and is currently being investigated in Phase III clinical trials. Like other echinocandins, it inhibits 1,3-beta-D-glucan synthesis, thus achieving fungicidal activity against virtually all Candida spp., including those resistant to fluconazole, and fungistatic activity against Aspergillus spp. Micafungin sodium is available for intravenous administration only. It has a favorable safety and drug-drug interaction profile. Micafungin has been approved by the US FDA for treatment of esophageal candidiasis and for antifungal prophylaxis during the pre-engraftment phase in patients undergoing hematopoietic stem cell transplantation. Considering the competitive pricing as well as the good tolerability and efficacy, at present micafungin seems to be another choice for both of these indications. Current research has proven micafungin sodium to add a rational and effective option to the antifungal armamentarium, especially in esophageal candidiasis refractory to fluconazole treatment, in those intolerant to triazoles or in patients needing concomitant therapy interacting with triazoles. In addition to the current indications, recent uncontrolled clinical trials have demonstrated a marked success in the treatment of candidemia and invasive candidiasis. Results from in vitro studies, animal models, small clinical trials, as well as the obvious comparison with the more established caspofungin, hint at possible future indications such as invasive aspergillosis and empirical antifungal therapy. However, preclinical data on micafungin is inconsistent and published well-designed clinical studies are scarce. More controlled and sufficiently scaled trials are imperative in order to establish micafungin as a reliable and safe option in clinical practice.

Topics: Animals; Antifungal Agents; Aspergillosis; Aspergillus; beta-Glucans; Candida; Candidiasis; Echinocandins; Humans; Lipopeptides; Lipoproteins; Micafungin; Mycoses; Peptides, Cyclic; Proteoglycans

The role played by antibodies (Abs) in the anticandidal defense has long been a matter of controversy, mostly due to the past inability to clearly define antigen specificity, the relationship between the type of immune response within the different settings of experimental and human candidiasis and, last but not least, a misunderstanding about the role of T helper cell in cell-mediated versus the humoral immunity. Contributory was also the lack of precise identification of virulence traits of the fungus which are the best candidates for a protective Ab response. In recent years, an impressive amount of experimental evidence, and also some clinical proof, have been generated which assign to Abs of defined specificity an important role in the anticandidal defense both at systemic and mucosal sites. Paradigmatic among them, Abs against defined virulence factors such as adhesins or aspartyl-proteinase enzymes, or against critical viability molecules such as beta-glucan, have been detected or generated which hold great promise for immunotherapeutic interventions in humans.

Topics: Animals; Antibodies, Fungal; Antibodies, Monoclonal; beta-Glucans; Candida albicans; Candidiasis; Candidiasis, Vulvovaginal; Disease Models, Animal; Female; Humans; Immunization, Passive

Topics: Antigens, Fungal; Aspergillosis; beta-Glucans; Biomarkers; Candidiasis; Colorimetry; Humans; Nephelometry and Turbidimetry; Pneumocystis Infections; Proteoglycans; Reference Values; Specimen Handling

To improve the outcome of invasive Candida infections, earlier empirical therapy before the establishment of the definitive diagnosis is considered to be necessary. However, appropriate use of empirical therapy for suspected candidiasis in febrile non-neutropenic surgical patients has not been defined. According to the guidelines from the Infectious Diseases Society of America, empirical therapy of suspected candidiasis in this setting should be limited to patients with Candida colonization of multiple sites, multiple other risk factors, and absence of any other causes of fever. A corrected colonization index which takes into account both the density and the degree of colonization of Candida spp. was shown to be the independent factors that predict subsequent candidal infection. It may also be appropriate to commence empirical therapy on the basis of a positive serodiagnostic test. Beta-D glucan is a cell-wall constituent of fungi, which is assumed to be a marker of fungal sepsis. However, it has been shown that beta-D-glucan can also be detected in patients without fungal infections, such as those on haemodialysis, and its positive predictive value is relatively low. The mono-utilization of beta-D-glucan for the assessment of fungal infection should therefore be avoided. The combined assessment of beta-D-glucan and extent of colonization with Candida spp. is believed to have the advantage of lessening the likelihood of a false positive reaction of beta-D-glucan.

Topics: beta-Glucans; Candidiasis; Critical Illness; Fluconazole; Humans

Topics: Antifungal Agents; beta-Glucans; Biomarkers; Candidiasis; Diagnosis, Differential; Echinocandins; Fluconazole; Glucans; Humans; Lipopeptides; Lipoproteins; Micafungin; Molecular Diagnostic Techniques; Peptides, Cyclic; Prognosis; Serologic Tests

Invasive fungal infections have emerged as important causes of morbidity and mortality in neutropenicand some other immunocompromised hosts; Candida and Aspergillus are among the major pathogens in this patient population. The clinical diagnosis of these infections is not specific and the traditional mycological methods for them not sensitive, with limits in the early detection of the pathogen. The potential additives or complements to the laboratory diagnosis of invasive candidiasis and aspergillosis are two non-culture-based methods, serodiagnostic methods and molecular ones. The former methods include the detection of pathogen-specific antigens, antibodies, metabolites and cell wall components. Several have already become standard laboratory tools and some others are under active investigation for developing new, more accurate detection systems. In this review, I will discuss the current status and future potential of serodiagnostic methods, highlighting both their technical and clinical implications.

Topics: Animals; Antibodies, Fungal; Antibody Specificity; Antigens, Fungal; Aspergillosis; Aspergillus; beta-Glucans; Biomarkers; Candida; Candidiasis; Cell Wall; Glucans; Humans; Mannans; Mannitol; Serologic Tests; Sugar Alcohols

The dramatic increase in nosocomial invasive mycoses over the past two decades has led to increased interest in the area of antifungal development. Unfortunately, the infusion of new diagnostic technology into the clinical mycology laboratory has lagged behind. Although newer, automated, continuous-monitoring blood culture systems are as sensitive as the older, manual "gold standard" system, the recovery of fungi from blood, as well as other clinical specimens, remains an insensitive marker for invasive fungal infection. Antigen assays for the rapid diagnosis of invasive fungal infections are in development, and galactomannan and glucan are two such promising antigens. Glucan may be present in the blood of patients with infection secondary to a wide variety of fungal pathogens, including Candida, Aspergillus, Fusarium, Saccharomyces, Trichosporon and Acremonium species. Early data suggest galactomannan may be present in the blood in detectable levels very early in the course of invasive aspergillosis. The galactomannan assay currently undergoing evaluations may actually be positive prior to the clinical suspicion for infection and may be useful in monitoring therapeutic response as well; however, the etiology of false-positive results following cytotoxic chemotherapy still has to be elucidated. PCR assays are also being developed in the research laboratory, however, the PCR assays will require a significant amount of adaptation and validation before they are ready for clinical care. Well-planned studies to evaluate the performance characteristics as well as appropriate clinical and cost-effective application of these new tests are needed.

Topics: Antigens, Fungal; Aspergillosis; beta-Glucans; Biotechnology; Candidiasis; Centrifugation; Culture Media; Enzyme-Linked Immunosorbent Assay; Fungemia; Glucans; Humans; Immunocompromised Host; Mannans; Medical Laboratory Science; Membrane Glycoproteins; Mycoses; Polymerase Chain Reaction

The therapeutic landscape for mycotic infections is shifting. New generation azoles that are active against clinically relevant, drug-resistant fungal pathogens have improved bioavailability, half-lives and safety profiles. Acylated cyclic peptide inhibitors of beta(1,3)glucan synthesis with origins as fungal metabolites provide an alternative and highly-selective mode of action, targeting cell-wall biogenesis in important pathogens such as Candida and Aspergillus species. The development, in each structural class, of compounds that have advanced to late-stage clinical trials is summarized in this review.

Topics: Antifungal Agents; Aspergillosis; Aspergillus; beta-Glucans; Candida; Candidiasis; Cell Wall; Clinical Trials as Topic; Glucans; Humans; Research

Topics: Autografts; beta-Glucans; Candidiasis; Child; Female; Humans; Medulloblastoma; Peripheral Blood Stem Cell Transplantation

The usefulness to diagnose and monitor invasive candidiasis (IC) using beta-glucan (BG) and antibodies against Candida albicans germ tubes (CAGT) was evaluated in a twice-weekly screening of 35 episodes in neutropenic adults at high risk. Three proven IC and three probable IC were assessed. Diagnostic levels of both markers were detected in 100% of proven IC and in 66% of probable IC. Sensitivity, specificity, positive and negative predictive values of BG and anti-CAGT antibodies detection were 83.3%, 89.6%, 62.5% and 96.3%, and 83.3%, 86.2%, 55.5%, 96.1%, respectively. False positive reactions occurred at a rate of 10.3% and 13.8% for the detection of BG and anti-CAGT antibodies, respectively. However, the patients with false positive results were different by each test. Both tests anticipated the clinical and radiological diagnosis, and the initiation of antifungal therapy in most patients. Combination of both tests improved specificity and positive predictive value to 100%.

Topics: Adolescent; Adult; Aged; Amphotericin B; Anemia, Aplastic; Antibodies, Fungal; Antibody Specificity; Antifungal Agents; Antigens, Fungal; beta-Glucans; Candida albicans; Candidiasis; False Positive Reactions; Female; Fluconazole; Fungemia; Hematologic Neoplasms; Hepatitis; Humans; Liposomes; Male; Middle Aged; Neutropenia; Patient Isolation; Predictive Value of Tests; Sensitivity and Specificity

We evaluated the effectiveness of the newly developed WAKO beta-glucan test which measures plasma (1-->3)-beta-D-glucan concentrations in the diagnosis of Candida deep mycosis. This test was compared to the Cand-Tec test. The WAKO beta-glucan test and Cand-Tec test were performed on 212 plasma specimens which were taken at 212 instances from 62 immunocompromised patients with serious diseases; i.e. hematopoietic malignancy, solid malignant tumor, etc. The sensitivities and specificities for the WAKO beta-glucan test were 84.8 and 85.9%, respectively, and 60.9 and 80.0% for the Cand-Tec test.

Topics: beta-Glucans; Candidiasis; Evaluation Studies as Topic; Glucans; Humans; Serologic Tests

(1-->3)-beta-D-Glucan is one of the major structural components of fungi, and it seems that it can be detected by the fractionated (1-->3)-beta-D-glucan-sensitive component from a Limulus lysate, factor G. We evaluated the concentration of (1-->3)-beta-D-glucan by using factor G and other fungal antigens in 24 patients with clinical evidence of mycosis and 36 healthy subjects. The mean concentration of (1-->3)-beta-D-glucan in the plasma of the healthy subjects was found to be 2.7 +/- 1.9 pg/ml (range, < 6.9 pg/ml), and it was found to be substantially higher in all 11 patients with candidemia (mean, 2,207.4 pg/ml; range, 325.4 to 8,449.0 pg/ml). Eight of those 11 patients with candidemia (73%) were positive for the Cand-Tec heat-labile candida antigen and only 3 patients (27%) were positive for mannan antigen. Three patients with invasive pulmonary aspergillosis were positive for galactomannan and had, in addition, high concentrations of (1-->3)-beta-D-glucan (mean, 323.3 pg/ml; range, 27.0 to 894.0 pg/ml). All 10 patients with cryptococcosis (including 2 patients with probable cryptococcosis) were positive for cryptococcal antigen by the Eiken latex test; however, (1-->3)-beta-D-glucan levels were not elevated in these patients (mean, 7.0 pg/ml; range, < 16.5 pg/ml). Our results indicated that (1-->3)-beta-D-glucan levels are elevated in patients with candidiasis and aspergillosis but not in those with cryptococcosis.

Topics: Adult; Antigens, Fungal; Aspergillosis; beta-Glucans; Candidiasis; Cryptococcosis; Female; Fungemia; Galactose; Glucans; Humans; Limulus Test; Male; Mannans; Middle Aged; Serologic Tests

The sensitivity of the (1-3)-β-D-glucan (BDG) diagnostic test for candidemia varies in different clinical settings, and its usefulness in early diagnosis of candidemia is suboptimal. We evaluated the sensitivity of the test for early candidemia prediction. All adult patients with culture-proven candidemia who underwent a serum Goldstream Fungus (1-3)-β-D-Glucan Test within seven days prior to candidemia onset at a tertiary referral hospital between January 2017 and May 2021 were included. Any-positive BDG results within seven days prior to candidemia onset were obtained in 38 out of 93 (40.9%) patients. The positive rate increased when the test was performed near the day of candidemia onset (

Topics: Adult; beta-Glucans; Candida; Candidemia; Candidiasis; Humans; Sensitivity and Specificity

Intra-abdominal candidiasis (IAC) is difficult to predict in critically ill patients with intra-abdominal infection, leading to the overuse of antifungal treatments. Serum and peritoneal 1.3-beta-D-glucan (sBDG and pBDG) have been proposed to confirm or invalidate the diagnosis of IAC, but clinical studies have reported inconsistent results, notably because of heterogeneous populations with a low IAC prevalence. This study aimed to identify a high-risk IAC population and evaluate pBDG and sBDG in diagnosing IAC.. This prospective multicenter noninterventional French study included consecutive critically ill patients undergoing abdominal surgery for abdominal sepsis. The primary objective was to establish the IAC prevalence. The secondary objective was to explore whether sBDG and pBDG could be used to diagnose IAC. Wako. Between 1 January 2020 and 31 December 2022, 199 patients were included. Patients were predominantly male (63%), with a median age of 66 [54-72] years. The IAC prevalence was 44% (87/199). The main IAC type was secondary peritonitis. Septic shock occurred in 63% of cases. After multivariate analysis, a nosocomial origin was associated with more IAC cases (P = 0.0399). The median pBDG level was significantly elevated in IAC (448 [107.5-1578.0] pg/ml) compared to non-IAC patients (133 [16.0-831.0] pg/ml), P = 0.0021. For a pBDG threshold of 45 pg/ml, the negative predictive value in assessing IAC was 82.3%. The median sBDG level with WT (n = 42) at day 1 was higher in IAC (5 [3.0-9.0] pg/ml) than in non-IAC patients (3 [3.0-3.0] pg/ml), P = 0.012. Similarly, median sBDG level with FA (n = 140) at day 1 was higher in IAC (104 [38.0-211.0] pg/ml) than in non-IAC patients (50 [23.0-141.0] pg/ml), P = 0.009. Combining a peritonitis score < 3, sBDG < 3.3 pg/ml (WT) and pBDG < 45 pg/ml (WT) yielded a negative predictive value of 100%.. In critically ill patients with intra-abdominal infection requiring surgery, the IAC prevalence was 44%. Combining low sBDG and pBDG with a low peritonitis score effectively excluded IAC and could limit unnecessary antifungal agent exposure.. The study was registered with ClinicalTrials.gov (ID number 03997929, first registered on June 24, 2019).

Topics: Aged; Antifungal Agents; beta-Glucans; Candidiasis; Critical Illness; Female; Glucans; Humans; Intraabdominal Infections; Male; Middle Aged; Peritonitis; Prospective Studies; Sensitivity and Specificity

Candida albicans is a major opportunistic pathogen of humans. It can grow as morphologically distinct yeast, pseudohyphae and hyphae, and the ability to switch reversibly among different forms is critical for its virulence. The relationship between morphogenesis and innate immune recognition is not quite clear. Dectin-1 is a major C-type lectin receptor that recognizes β-glucan in the fungal cell wall. C. albicans β-glucan is usually masked by the outer mannan layer of the cell wall. Whether and how β-glucan masking is differentially regulated during hyphal morphogenesis is not fully understood. Here we show that the endo-1,3-glucanase Eng1 is differentially expressed in yeast, and together with Yeast Wall Protein 1 (Ywp1), regulates β-glucan exposure and Dectin-1-dependent immune activation of macrophage by yeast cells. ENG1 deletion results in enhanced Dectin-1 binding at the septa of yeast cells; while eng1 ywp1 yeast cells show strong overall Dectin-1 binding similar to hyphae of wild-type and eng1 mutants. Correlatively, hyphae of wild-type and eng1 induced similar levels of cytokines in macrophage. ENG1 expression and Eng1-mediated β-glucan trimming are also regulated by antifungal drugs, lactate and N-acetylglucosamine. Deletion of ENG1 modulates virulence in the mouse model of hematogenously disseminated candidiasis in a Dectin-1-dependent manner. The eng1 mutant exhibited attenuated lethality in male mice, but enhanced lethality in female mice, which was associated with a stronger renal immune response and lower fungal burden. Thus, Eng1-regulated β-glucan exposure in yeast cells modulates the balance between immune protection and immunopathogenesis during disseminated candidiasis.

Topics: Animals; beta-Glucans; Candida albicans; Candidiasis; Female; Glucan Endo-1,3-beta-D-Glucosidase; Male; Mice; Mice, Inbred C57BL; Virulence

Combating fungal pathogens poses metabolic challenges for neutrophils, key innate cells in anti-Candida albicans immunity, yet how host-pathogen interactions cause remodeling of the neutrophil metabolism is unclear. We show that neutrophils mediate renal immunity to disseminated candidiasis by upregulating glucose uptake via selective expression of glucose transporter 1 (Glut1). Mechanistically, dectin-1-mediated recognition of β-glucan leads to activation of PKCδ, which triggers phosphorylation, localization, and early glucose transport by a pool of pre-formed Glut1 in neutrophils. These events are followed by increased Glut1 gene transcription, leading to more sustained Glut1 accumulation, which is also dependent on the β-glucan/dectin-1/CARD9 axis. Card9-deficient neutrophils show diminished glucose incorporation in candidiasis. Neutrophil-specific Glut1-ablated mice exhibit increased mortality in candidiasis caused by compromised neutrophil phagocytosis, reactive oxygen species (ROS), and neutrophil extracellular trap (NET) formation. In human neutrophils, β-glucan triggers metabolic remodeling and enhances candidacidal function. Our data show that the host-pathogen interface increases glycolytic activity in neutrophils by regulating Glut1 expression, localization, and function.

Topics: Animals; beta-Glucans; Candida albicans; Candidiasis; CARD Signaling Adaptor Proteins; Glucose; Glucose Transporter Type 1; Mice; Neutrophils

The incidence of Aspergillus and Candida CNS infection, which are characterised by high mortality rates, is underestimated. This underdiagnosis presumably results from the limitations of available diagnostic tools and the need for invasive sampling. Little is known about the role of serologic biomarkers in the setting of CNS aspergillosis and candidiasis.. Serum and cerebrospinal fluid (CSF; 10) samples of 19 patients, whose CNS specimens yielded growth of Aspergillus or Candida, were analysed for different biomarkers for fungal infection, that is galactomannan (GM), galactomannoprotein (GP), mannan, anti-mannan-antibodies and β-1,3-D-glucan (BDG). Serum and CSF specimens of time-matched patients (two each for every case of fungal CNS infection) were included as controls.. Galactomannan, GP and BDG seropositivity was found in one, two and three of five cases of CNS aspergillosis. BDG and mannan/anti-mannan-antibody sensitivity in proven CNS candidiasis was 40% and 20%, respectively. Applying the serum cut-off, sensitivity in CSF testing was 100% for GM and BDG and 50% for mannans. While serum specificity for all assays ranged from 89 to 97%, specificity for CSF BDG was only 70%. No false-positive GM results from CSF were obtained.. Sensitivity for diagnosing CNS aspergillosis and CNS candidiasis from serum is mediocre for all serological biomarkers. GM testing in CSF proved excellent performance. With a sensitivity of 100% but a specificity of only 70%, CSF BDG might be most useful when used in patients with a high pre-test probability.

Topics: Aspergillosis; Aspergillus; beta-Glucans; Biomarkers; Candida; Candidiasis; Central Nervous System; Galactose; Humans; Mannans; Sensitivity and Specificity

This study aimed to characterize the baseline values and dynamics of serum (1,3)-Beta-D-Glucan (BDG) in neonates at high risk of neonatal invasive candidiasis (NIC); as well as to determine the effect of various clinical variables on these levels. Single center prospective cohort study was performed including 20 high-risk neonates (gestational age < 29 weeks and/or birth weight ≤ 1000 gr). Samples for BDG (Fungitell® assay) were obtained twice weekly during 6 weeks. Nineteen neonates were enrolled with a median gestational age of 25 weeks (IQR 24-27), median birth weight of 730 gr (IQR 650-810). None of the neonates was diagnosed with NIC. 190 serum samples were included. The median BDG value was 59 pg/ml (IQR 30-148), mean was 119 pg/ml (SD ± 154). A total of 42.1% (80/190) samples showed values ≥80 pg/ml, with all the neonates presenting at least one test above this cut-off. Neonatal age did not show an association with BDG levels. Exposure to steroids and the use of a heel prick as sampling method were associated with statistically significant higher BDG levels. The BDG levels showed high variability and in a significant proportion of samples values were above the threshold for positivity (e.g., ≥80 pg/ml) in the absence of NIC. The exposure to postnatal steroids and the heel prick as the method of blood sampling were associated with higher BDG levels.. Neonatal invasive candidiasis (NIC) presents high morbi-mortality. The diagnosis of NIC is often challenging. Blood cultures have limitations and better diagnostic tools are needed. Beta-D-glucan is a diagnostic marker which could be potentially used, although still more clinical data are required.

Topics: Animals; beta-Glucans; Birth Weight; Candidiasis; Candidiasis, Invasive; Humans; Prospective Studies; Sensitivity and Specificity

Topics: beta-Glucans; Biomarkers; Candida; Candidiasis; Candidiasis, Invasive; Humans; Sensitivity and Specificity

We previously reported medicinal chemistry efforts that identified MK-5204, an orally efficacious β-1,3-glucan synthesis inhibitor derived from the natural product enfumafungin. Further extensive optimization of the C2 triazole substituent identified 4-pyridyl as the preferred replacement for the carboxamide of MK-5204, leading to improvements in antifungal activity in the presence of serum, and increased oral exposure. Reoptimizing the aminoether at C3 in the presence of this newly discovered C2 substituent, confirmed that the (R) t-butyl, methyl aminoether of MK-5204 provided the best balance of these two key parameters, culminating in the discovery of ibrexafungerp, which is currently in phase III clinical trials. Ibrexafungerp displayed significantly improved oral efficacy in murine infection models, making it a superior candidate for clinical development as an oral treatment for Candida and Aspergillus infections.

Topics: Administration, Oral; Animals; Antifungal Agents; Aspergillosis; Aspergillus; beta-Glucans; Candida albicans; Candidiasis; Disease Models, Animal; Glycosides; Half-Life; Mice; Structure-Activity Relationship; Triterpenes

Trained immunity, induced by β-glucan in monocytes, is mediated by activating metabolic pathways that result in epigenetic rewiring of cellular functional programs; however, molecular mechanisms underlying these changes remain unclear. Here, we report a key immunometabolic and epigenetic pathway mediated by the miR-9-5p-isocitrate dehydrogenase 3α (IDH3α) axis in trained immunity. We found that β-glucan-trained miR-9-5p-/- monocytes showed decreased IL-1β, IL-6, and TNF-α production after LPS stimulation. Trained miR-9-5p-/- mice produced decreased levels of proinflammatory cytokines upon rechallenge in vivo and had worse protection against Candida albicans infection. miR-9-5p targeted IDH3α and reduced α-ketoglutarate (α-KG) levels to stabilize HIF-1α, which promoted glycolysis. Accumulating succinate and fumarate via miR-9-5p action integrated immunometabolic circuits to induce histone modifications by inhibiting KDM5 demethylases. β-Glucan-trained monocytes exhibited low IDH3α levels, and IDH3α overexpression blocked the induction of trained immunity by monocytes. Monocytes with IDH3α variants from autosomal recessive retinitis pigmentosa patients showed a trained immunity phenotype at immunometabolic and epigenetic levels. These findings suggest that miR-9-5p and IDH3α act as critical metabolic and epigenetic switches in trained immunity.

Topics: Animals; beta-Glucans; Candida albicans; Candidiasis; Epigenesis, Genetic; Fumarates; Glycolysis; Hypoxia-Inducible Factor 1, alpha Subunit; Immunity, Innate; Immunologic Memory; Interleukin-1beta; Interleukin-6; Isocitrate Dehydrogenase; Ketoglutaric Acids; Lipopolysaccharides; Metabolic Networks and Pathways; Mice; Mice, Knockout; MicroRNAs; Monocytes; Retinitis Pigmentosa; Succinic Acid; Tumor Necrosis Factor-alpha

Masking the immunogenic cell wall epitope ß(1,3)-glucan under an outer layer of mannosylated glycoproteins is an important virulence factor deployed by Candida albicans during infection. Consequently, increased ß(1,3)-glucan exposure (unmasking) reveals C. albicans to the host's immune system and attenuates its virulence. We have previously shown that activation of the Cek1 MAPK pathway via expression of a hyperactive allele of an upstream kinase (STE11ΔN467) induced unmasking. It also increased survival of mice in a murine disseminated candidiasis model and attenuated kidney fungal burden by ≥33 fold. In this communication, we utilized cyclophosphamide-induced immunosuppression to test if the clearance of the unmasked STE11ΔN467 mutant was dependent on the host immune system. Suppression of the immune response by cyclophosphamide reduced the attenuation in fungal burden caused by the STE11ΔN467 allele. Moreover, specific depletion of neutrophils via 1A8 antibody treatment also reduced STE11ΔN467-dependent fungal burden attenuation, but to a lesser extent than cyclophosphamide, demonstrating an important role for neutrophils in mediating fungal clearance of unmasked STE11ΔN467 cells. In an effort to understand the mechanism by which Ste11ΔN467 causes unmasking, transcriptomics were used to reveal that several components in the Cek1 MAPK pathway were upregulated, including the transcription factor CPH1 and the cell wall sensor DFI1. In this report we show that a cph1ΔΔ mutation restored ß(1,3)-glucan exposure to wild-type levels in the STE11ΔN467 strain, confirming that Cph1 is the transcription factor mediating Ste11ΔN467-induced unmasking. Furthermore, Cph1 is shown to induce a positive feedback loop that increases Cek1 activation. In addition, full unmasking by STE11ΔN467 is dependent on the upstream cell wall sensor DFI1. However, while deletion of DFI1 significantly reduced Ste11ΔN467-induced unmasking, it did not impact activation of the downstream kinase Cek1. Thus, it appears that once stimulated by Ste11ΔN467, Dfi1 activates a parallel signaling pathway that is involved in Ste11ΔN467-induced unmasking.

Topics: Animals; beta-Glucans; Candida albicans; Candidiasis; Cell Wall; Fungal Proteins; Gene Expression Regulation, Fungal; Mice; Mice, Inbred ICR; Neutrophils; Transcription Factors; Virulence

Toll-like receptor (TLR) agonists drive hematopoietic stem and progenitor cells (HSPCs) to differentiate along the myeloid lineage. In this study, we used an HSPC transplantation model to investigate the possible direct interaction of β-glucan and its receptor (dectin-1) on HSPCs

Topics: Animals; beta-Glucans; Candida albicans; Candidiasis; Cell Differentiation; Female; Hematopoietic Stem Cells; Immunity, Innate; Lectins, C-Type; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Myeloid Differentiation Factor 88; Signal Transduction; Stem Cells; Toll-Like Receptor 2

Our previously reported efforts to produce an orally active β-1,3-glucan synthesis inhibitor through the semi-synthetic modification of enfumafungin focused on replacing the C2 acetoxy moiety with an aminotetrazole and the C3 glycoside with a N,N-dimethylaminoether moiety. This work details further optimization of the C2 heterocyclic substituent, which identified 3-carboxamide-1,2,4-triazole as a replacement for the aminotetrazole with comparable antifungal activity. Alkylation of either the carboxamidetriazole at C2 or the aminoether at C3 failed to significantly improve oral efficacy. However, replacement of the isopropyl alpha amino substituent with a t-butyl, improved oral exposure while maintaining antifungal activity. These two structural modifications produced MK-5204, which demonstrated broad spectrum activity against Candida species and robust oral efficacy in a murine model of disseminated Candidiasis without the N-dealkylation liability observed for the previous lead.

Topics: Administration, Oral; Animals; Antifungal Agents; beta-Glucans; Candida; Candidiasis; Disease Models, Animal; Glucosyltransferases; Glycosides; Half-Life; Mice; Microbial Sensitivity Tests; Stereoisomerism; Structure-Activity Relationship; Triazoles; Triterpenes

A bioassay based on the detection of beta-glucan, a constituent of the cell wall of fungi, has been successfully used to diagnose fungal infections in a variety of biological fluids but not yet in the amniotic fluid.. To determine the diagnostic performance of a beta-glucan bioassay in the detection of Candida species in the amniotic fluid of women who either did or did not have an intrauterine contraceptive device (IUD) in place during an episode of spontaneous preterm parturition.. The study population comprised women who had a singleton pregnancy without congenital or chromosomal abnormalities, who experienced preterm labor or preterm prelabor rupture of the fetal membranes, and who underwent a transabdominal amniocentesis for clinical indications. Samples of amniotic fluid were cultured for aerobic and anaerobic bacteria, genital mycoplasmas, and Candida species, and assayed for beta-glucan, using the (1→3)-beta-d-glucan-specific Limulus amebocyte lysate test (beta-glucan assay) in all cases. Amniotic fluid interleukin (IL)-6 assay results were also available for all cases. The beta-glucan assay takes about 1 hour to run: a concentration >80 pg/mL was considered positive for fungi. Sterile intra-amniotic inflammation of the amniotic cavity was defined by the presence of an amniotic fluid IL-6 concentration ≥2.6 ng/mL and a negative amniotic fluid culture.. (1) One hundred ninety-seven (197) women met the study criteria, of whom 58 (29.4%) had an IUD in place; (2) 20 (10.2%) women had a culture of proven intra-amniotic Candida species-related infection, 19 of whom had a positive beta-glucan assay [sensitivity, 95% (19/20; 95% confidence interval (CI): 75.1-99.9%)]; and (3) the specificity of the beta-glucan assay was 75.1% [133/177; 95% CI: 68.1-99.9%]. It was affected by the presence of nonfungal intra-amniotic infections and an IUD, but not by the presence of sterile intra-amniotic inflammation, and there was a significant interaction between the presence of an IUD and nonfungal intra-amniotic infections (estimated for the interaction effect = 2.1923, p value =.026). The assay's specificity was reduced when nonfungal intra-amniotic infections were diagnosed but only in women who did not have an IUD. Among women without an IUD, the assay's specificity was 91.4% (117/128); it was 93% (106/114) for those without intra-amniotic infection, and 78.6% (11/14) for those with a nonfungal intra-amniotic infection; the difference was not significant (p = .09). Among women with an IUD, the assay's specificity was 32.7% (16/49); 42.9% (9/21) for those with a nonfungal intra-amniotic infection; and 25% (7/28) for those without intra-amniotic infection; and the difference was significant (p = .03).. The beta-glucan assay is a sensitive, rapid, point-of-care test used to diagnose intra-amniotic Candida species-related infection, and it has a high specificity in pregnant women who did not have an IUD in place.

Topics: Adult; Amniocentesis; Amniotic Fluid; beta-Glucans; Candida; Candidiasis; Case-Control Studies; Female; Fetal Membranes, Premature Rupture; Gestational Age; Humans; Intrauterine Devices; Predictive Value of Tests; Pregnancy; Pregnancy Complications, Infectious; Ultrasonography, Prenatal; Young Adult

β-1,6-glucan is an important component of the fungal cell wall. The β-1,6-glucan synthase gene KRE6 was thought to be essential in the fungal pathogen Candida albicans because it could not be deleted in previous efforts. Also, the role of its homolog SKN1 was unclear because its deletion caused no defects. Here, we report the construction and characterization of kre6Δ/Δ, skn1Δ/Δ and kre6Δ/Δ skn1Δ/Δ mutants in C. albicans. While deleting KRE6 or SKN1 had no obvious phenotypic consequence, deleting both caused slow growth, cell separation failure, cell wall abnormalities, diminished hyphal growth, poor biofilm formation and loss of virulence in mice. Furthermore, the GPI-linked cell surface proteins Hwp1 and the invasin Als3 or Ssa1 were not detected in kre6Δ/Δ skn1Δ/Δ mutant. In GMM medium, RT-qPCR and western blotting revealed a constitutive expression of KRE6 and growth conditions-associated activation of SKN1. Like many hypha-specific genes, SKN1 is repressed by Nrg1, but its activation does not involve the transcription factor Efg1. Dysregulation of SKN1 reduces C. albicans ability to damage epithelial and endothelial cells and attenuates its virulence. Given the vital role of β-1,6-glucan synthesis in C. albicans physiology and virulence, Kre6 and Skn1 are worthy targets for developing antifungal agents.

Topics: Animals; beta-Glucans; Candida albicans; Candidiasis; Disease Models, Animal; Gene Deletion; Glucosyltransferases; Mice; Virulence; Virulence Factors

Since molecular genotyping has been established for the Candida species, studies have found that a single Candida strain (endemic strain) can persist over a long period of time and results in the spread of nosocomial invasive candidiasis without general characteristics of horizontal transmissions. Our previous study also found the existence of endemic strains in a cancer center in Tianjin, China. In the current study, we performed further investigation on endemic and non-endemic Candida albicans strains, with the aim of explaining the higher morbidity of endemic strains. In an in vivo experiment, mice infected with endemic strains showed significantly shorter survival time and higher kidney fungal burdens compared to mice infected with non-endemic strains. In an in vitro experiment, the killing percentage of neutrophils to endemic strains was significantly lower than that to non-endemic strains, which is positively linked to the ratio of LC3B-II/I in neutrophils. An immunofluorescence assay showed more β-1,3-glucan exposure on the cell walls of non-endemic strains compared to endemic strains. After blocking the β-glucan receptor (CR3) or inhibiting downstream kinase (SYK) in neutrophils, the killing percent to C. albicans (regardless of endemic and non-endemic strains) and the ratio of LC3B-II/I of neutrophils were significantly decreased. These data suggested that the killing capability of neutrophils to C. albicans was monitored by β-1,3-glucan via CR3/SYK pathway-dependent LC3B-II accumulation and provided an explanation for the variable killing capability of neutrophils to different strains of C. albicans, which would be beneficial in improving infection control and therapeutic strategies for invasive candidiasis.

Topics: Animals; beta-Glucans; Candida albicans; Candidiasis; Cells, Cultured; Humans; Macrophage-1 Antigen; Male; Mice; Mice, Inbred BALB C; Microtubule-Associated Proteins; Neutrophils; Syk Kinase

Topics: Aspergillosis; beta-Glucans; Candidiasis; Humans; Mycoses; Plasma; Pneumonia, Pneumocystis; Reagent Kits, Diagnostic; Sensitivity and Specificity; Serologic Tests; Serum

β-(1→3)-D-Glucan is an essential component of the fungal cell wall. Mouse monoclonal antibodies (mAbs) against synthetic nona-β-(1→3)-D-glucoside conjugated with bovine serum albumin (BSA) were generated using hybridoma technology. The affinity constants of two selected mAbs, 3G11 and 5H5, measured by a surface plasmon resonance biosensor assay using biotinylated nona-β-(1→3)-D-glucan as the ligand, were approximately 11 nM and 1.9 nM, respectively. The glycoarray, which included a series of synthetic oligosaccharide derivatives representing β-glucans with different lengths of oligo-β-(1→3)-D-glucoside chains, demonstrated that linear tri-, penta- and nonaglucoside, as well as a β-(1→6)-branched octasaccharide, were recognized by mAb 5H5. By contrast, only linear oligo-β-(1→3)-D-glucoside chains that were not shorter than pentaglucosides (but not the branched octaglucoside) were ligands for mAb 3G11. Immunolabelling indicated that 3G11 and 5H5 interact with both yeasts and filamentous fungi, including species from Aspergillus, Candida, Penicillium genera and Saccharomyces cerevisiae, but not bacteria. Both mAbs could inhibit the germination of Aspergillus fumigatus conidia during the initial hours and demonstrated synergy with the antifungal fluconazole in killing C. albicans in vitro. In addition, mAbs 3G11 and 5H5 demonstrated protective activity in in vivo experiments, suggesting that these β-glucan-specific mAbs could be useful in combinatorial antifungal therapy.

Topics: Animals; Antibodies, Monoclonal; Antifungal Agents; Antigens, Fungal; Aspergillus fumigatus; beta-Glucans; Candida albicans; Candidiasis; Cell Wall; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Female; Fluconazole; Humans; Mice; Microbial Sensitivity Tests; Treatment Outcome

Recognition of the fungal cell wall carbohydrate β-glucan by the host receptor Dectin-1 elicits broad immunomodulatory responses, such as phagocytosis and activation of oxidative burst. These responses are essential for engulfing and killing fungal pathogens. Phagocytic monocytes are key mediators of these early host inflammatory responses to infection. Remarkably, whether phagocytosis of fungal β-glucan leads to an inflammatory response in human monocytes remains to be established. Here, we show that phagocytosis of heat-killed Candida albicans is essential to trigger inflammation and cytokine release. By contrast, inhibition of actin-dependent phagocytosis of particulate (1-3,1-6)-β-glucan induces a strong inflammatory signature. Sustained monocyte activation, induced by fungal β-glucan particles upon actin cytoskeleton disruption, relies on Dectin-1 and results in the classical caspase-1 inflammasome formation through NLRP3, generation of an oxidative burst, NF-κB activation, and increased inflammatory cytokine release. PI3K and NADPH oxidase were crucial for both cytokine secretion and ROS generation, whereas Syk signaling mediated only cytokine production. Our results highlight the mechanism by which phagocytosis tightly controls the activation of phagocytes by fungal pathogens and strongly suggest that actin cytoskeleton dynamics are an essential determinant of the host's susceptibility or resistance to invasive fungal infections.

Topics: Actin Cytoskeleton; beta-Glucans; Candida albicans; Candidiasis; Cells, Cultured; Cytokines; Fungal Polysaccharides; Humans; Lectins, C-Type; Leukocytes, Mononuclear; NADPH Oxidases; NF-kappa B; NLR Family, Pyrin Domain-Containing 3 Protein; Phagocytes; Phagocytosis; Phosphatidylinositol 3-Kinases; Reactive Oxygen Species; Respiratory Burst

Definitive diagnosis of invasive candidiasis (IC) may be difficult to achieve in patients with haematological malignancy (PHM). We aimed to evaluate the performance of BDG for the diagnosis and the follow-up of IC in PHM.. We retrospectively reviewed the serological data of BDG assay in adult and paediatric PHM, who developed candidemia or chronic disseminated candidiasis (CDC) through a 4-year period. Sensitivity and kinetics of BDG were determined for both clinical forms.. In a panel of 3027 PHM, incidence rates of candidemia and CDC ranged between 0.74 and 0.77 and 0.30 and 0.44 according to the group of patients. At the time of diagnosis, 43.5% and 73% of cases of candidemia and CDC had a positive BDG assay, respectively. We found a significant correlation between the level of BDG at diagnosis and the outcome of candidemia (p = 0.022). In all cases of CDC, BDG negative results were obtained 2 to 6 months before recovery of the CT-scan lesions.. BDG exhibits a low sensitivity to detect IC in PHM, but its kinetics correlates the clinical outcome. Additional studies are warranted in patients with CDC to evaluate the interest of monitoring BDG levels to anticipate the discontinuation of antifungal maintenance therapy.

Topics: Aged; Antibodies, Fungal; Antifungal Agents; beta-Glucans; Candida; Candidemia; Candidiasis; Candidiasis, Invasive; Follow-Up Studies; Hematologic Neoplasms; Humans; Intensive Care Units; Kinetics; Middle Aged; Retrospective Studies; Sensitivity and Specificity

We assessed the potential role of T2Candida MR (T2MR) and serological biomarkers [β-d-glucan (BDG) or Candida albicans germ tube antibodies (CAGTA)], alone or in combination with standard cultures, for identifying patients with suspected invasive candidiasis (IC), who may benefit from maintaining antifungal therapy.. Prospective observational multicentre study including all adult patients receiving empirical antifungal therapy for suspected IC, from January to June 2017. CAGTA, BDG and T2MR were determined at baseline and at +2 and +4 days after enrolment. Primary endpoint was the diagnostic value of CAGTA, BDG and T2MR, alone or in combination with standard culture, to predict diagnosis of IC and/or mortality in the first 7 days after starting antifungal therapy (poor outcome).. Overall, 14/49 patients (28.6%) had a poor outcome (7 died within the first 7 days of antifungal therapy, whereas 7 ended with a diagnosis of IC). CAGTA [3/14 (21.4%) versus 8/35 (22.9%), P = 1] and BDG [8/14 (57.1%) versus 17/35 (48.6%), P = 0.75] results were similar in poor- and good-outcome patients. Conversely, a positive T2MR was associated with a higher risk of poor outcome [5/14 (35.7%) versus 0/35 (0.0%) P = 0.0001]. Specificity and positive predictive value of a positive T2MR for predicting poor outcome were both 100%, with a negative predictive value of 79.6%. After testing the combinations of biomarkers/standard cultures and T2MR/standard cultures, the combination of T2MR/standard cultures showed a high capacity to discriminate patients with poor outcome from those with good clinical evolution.. T2MR may be of significant utility to identify patients who may benefit from maintaining antifungal therapy.

Topics: Adult; Aged; Antibodies, Fungal; Antifungal Agents; beta-Glucans; Blood Culture; Candidiasis; Candidiasis, Invasive; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Pilot Projects; Prospective Studies

Candida albicans belongs to the normal microbial flora on epithelial surfaces of humans. However, under certain, still not fully understood conditions, it can become pathogenic and cause a spectrum of diseases, from local infections to life-threatening septicemia. We investigated a panel of antimicrobial proteins and peptides (AMPs), potentially involved in mucosal immunity against this pathogen. Out of six studied AMPs, psoriasin was most up-regulated during a mucosal infection, an acute episode of recurrent Candida vulvovaginitis, although candidacidal activity has not been demonstrated. We here show that psoriasin binds to β-glucan, a basic component of the C. albicans cell wall, and thereby inhibits adhesion of the pathogen to surfaces and increases IL-8 production by mucosal epithelial cells. In conclusion, we show a novel mechanism of action of psoriasin. By inhibiting C. albicans adhesion and by enhancing cytokine production, psoriasin contributes to the immune response against C. albicans. KEY MESSAGES: The antimicrobial peptide psoriasin is highly up-regulated during a local mucosal infection, Candida albicans vulvovaginitis. Psoriasin binds to β-glucan in the Candida albicans cell wall and thereby inhibits adhesion of the pathogen. Binding of psoriasin to Candida albicans induces an immune response by mucosal epithelial cells.

Topics: Adult; beta-Glucans; Candida albicans; Candidiasis; Cell Adhesion; Cell Line; Female; Humans; S100 Calcium Binding Protein A7; Young Adult

Echinocandins are antifungal agents that specifically inhibit the biosynthesis of 1,3-β-D-glucan, a major structural component of fungal cell walls. Echinocandins are recommended as first-line or alternative/salvage therapy for candidiasis and aspergillosis in antifungal guidelines of various countries. Resistance to echinocandins has been reported in recent years. The mechanism of echinocandin resistance involves amino acid substitutions in hot spot regions of the FKS gene product, the catalytic subunit of 1,3-β-D-glucan synthase. This resistance mechanism contributes to not only acquired resistance in Candida spp., but also inherent resistance in some pathogenic fungi. An understanding of the echinocandin resistance mechanism is important to develop both effective diagnosis and treatment options for echinocandin-resistant fungal diseases.

Topics: Amino Acid Substitution; Antifungal Agents; Aspergillosis; Aspergillus; beta-Glucans; Candida; Candidiasis; Catalytic Domain; Drug Resistance, Fungal; Echinocandins; Glucosyltransferases

Decision to start an anti-fungal therapy in intra-abdominal candidiasis (IAC) is complex. Yeast culture, considered the gold standard, suffers from a delayed response time and exposes the patient to delayed introduction of anti-fungal therapy. We sought to evaluate the performance and feasibility of measuring 1,3-β-D-glucan (1,3-BDG) in the peritoneal fluid (PF) for the diagnosis of IAC.. We analyzed retrospectively all PF obtained during abdominal surgery for critically ill adult patients presenting intra-abdominal infections. For each PF sample, direct examination, bacterial and fungal culture, fungal PCR and 1,3-BDG measurements were performed. The diagnostic performance of each technique and the Peritonitis score were calculated considering the positive yeast culture as the reference. The levels of 1,3-BDG were compared between IAC and non-IAC patients.. During an 8-month period in 2016, 33 PF samples were recovered. Median (interquartile range) SAPS 2 and SOFA scores were 44 (9-94) and 9 (4-15), respectively. There were seven cases of IAC, 14 of bacterial peritonitis and 12 of undocumented peritonitis. All IAC cases were secondary peritonitis, with a 1,3-BDG level of 1461 (325-5000) versus 224 (68-1357) pg/mL in the non-IAC group (P=0.03). When the 1,3-BDG level was ≤310 pg/mL, its negative predictive value was 100%.. In secondary peritonitis, a peritoneal measurement of 1,3-BDG ≤310 pg/mL could rule out IAC.

Topics: Abdomen; Aged; Ascitic Fluid; beta-Glucans; Candidiasis; Cohort Studies; Critical Illness; Feasibility Studies; Female; Humans; Male; Middle Aged; Pilot Projects; Proteoglycans; Retrospective Studies

Inflammatory bowel diseases (IBD) are a multifactorial disorder. Our understanding of the role of bacteria in the pathogenesis of IBD has increased substantially; however, only scarce data exist regarding the role of commensal fungi in maintaining intestinal homeostasis and triggering IBD. Candida albicans (C. albicans) is a member of the intestinal mycobiome and proposed to contribute to IBD pathogenesis. We aimed to investigate the influence of the two morphologies of C. albicans, yeast and hypha, on epithelial cells and T cells from IBD patients versus healthy controls. We found that C. albicans was recognized by both epithelial cells lines and T cells. In the intestinal epithelial cell line, Caco-2, response to hypha was different than to yeast cells, and this was mimicked by synthetic β-glucans and Pam3CSK4. Unstimulated T cells exhibited increased activation and pro-inflammatory cytokine secretion upon exposure, while there was no effect on apoptosis or proliferation. In contrast, C. albicans-challenged CD3-stimulated T-cells exhibited decreased activation, cytokine secretion, apoptosis, and proliferation, suggesting reciprocal responsiveness to C. albicans. Glycans alone did not mimic abovementioned influences on T cells, suggesting alternative modes of recognition. In conclusion, we provide evidence for glycan dependent and independent recognition of C. albicans by epithelial cells and T cells.

Topics: Apoptosis; beta-Glucans; Caco-2 Cells; Candida albicans; Candidiasis; Cell Line; Cell Line, Tumor; Cell Proliferation; Epithelial Cells; Host-Pathogen Interactions; Humans; Hyphae; Inflammatory Bowel Diseases; Intestinal Mucosa; Intestines; T-Lymphocytes

Infection by invasive fungi, such as

Topics: Animals; Aspergillosis; Aspergillus fumigatus; B-Lymphocytes; beta-Glucans; Candida albicans; Candidiasis; Cryptococcosis; Cryptococcus neoformans; Immunity, Innate; Mannans; Mice; Mice, Inbred C57BL; Mice, Knockout; NF-kappa B; Polysaccharides; RAW 264.7 Cells; Receptors, IgE; Receptors, Pattern Recognition; Signal Transduction

β-Glucan-induced trained immunity in myeloid cells leads to long-term protection against secondary infections. Although previous studies have characterized this phenomenon, strategies to boost trained immunity remain undefined. We found that β-glucan-trained macrophages from mice with a myeloid-specific deletion of the phosphatase SHIP-1 (LysMΔSHIP-1) showed enhanced proinflammatory cytokine production in response to lipopolysaccharide. Following β-glucan training, SHIP-1-deficient macrophages exhibited increased phosphorylation of Akt and mTOR targets, correlating with augmented glycolytic metabolism. Enhanced training in the absence of SHIP-1 relied on histone methylation and acetylation. Trained LysMΔSHIP-1 mice produced increased amounts of proinflammatory cytokines upon rechallenge in vivo and were better protected against Candida albicans infection compared with control littermates. Pharmacological inhibition of SHIP-1 enhanced trained immunity against Candida infection in mouse macrophages and human peripheral blood mononuclear cells. Our data establish proof of concept for improvement of trained immunity and a strategy to achieve it by targeting SHIP-1.

Topics: Animals; beta-Glucans; Candida albicans; Candidiasis; Humans; Immunity; Macrophages; Mice, Inbred C57BL; Myeloid Cells; Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases

While Candida pneumonia is life-threatening, biomarker measurements to early detect suspected Candida pneumonia are lacking. This study compared the diagnostic values of measuring levels of (1, 3)-β-D-glucan in endotracheal aspirate, bronchoalveolar lavage fluid, and serum to detect suspected Candida pneumonia in immunocompromised and critically ill patients.. This prospective, observational study enrolled immunocompromised, critically ill, and ventilated patients with suspected fungal pneumonia in mixed intensive care units from November 2010 to October 2011. Patients with D-glucan confounding factors or other fungal infection were excluded. Endotracheal aspirate, bronchoalveolar lavage fluid and serum were collected from each patient to perform a fungal smear, culture, and D-glucan assay.. After screening 166 patients, 31 patients completed the study and were categorized into non-Candida pneumonia/non-candidemia (n = 18), suspected Candida pneumonia (n = 9), and non-Candida pneumonia/candidemia groups (n = 4). D-glucan levels in endotracheal aspirate or bronchoalveolar lavage were highest in suspected Candida pneumonia, while the serum D-glucan level was highest in non-Candida pneumonia/candidemia. In all patients, the D-glucan value in endotracheal aspirate was positively correlated with that in bronchoalveolar lavage fluid. For the detection of suspected Candida pneumonia, the predictive performance (sensitivity/specificity/D-glucan cutoff [pg/ml]) of D-glucan in endotracheal aspirate and bronchoalveolar lavage fluid was 67%/82%/120 and 89%/86%/130, respectively, accounting for areas under the receiver operating characteristic curve of 0.833 and 0.939 (both P < 0.05), respectively. Measuring serum D-glucan was of no diagnostic value (area under curve =0.510, P = 0.931) for the detection of suspected Candida pneumonia in the absence of concurrent candidemia.. D-glucan levels in both endotracheal aspirate and bronchoalveolar lavage, but not in serum, provide good diagnostic values to detect suspected Candida pneumonia and to serve as potential biomarkers for early detection in this patient population.

Topics: Adult; Aged; beta-Glucans; Biomarkers; Bronchoalveolar Lavage Fluid; Candidemia; Candidiasis; Critical Illness; Early Diagnosis; Female; Humans; Immunocompromised Host; Intensive Care Units; Male; Middle Aged; Pneumonia; Prospective Studies; Proteoglycans; Sensitivity and Specificity

A case is reported of Candida glabrata infective endocarditis (IE) treated without surgical intervention. The study aim was to: (i) briefly discuss the outcomes of other documented cases of fungal IE managed medically with fluconazole; (ii) discuss the (1→3)-β-D-glucan assay and its previously studied role in the diagnosis of invasive fungal infections; and (iii) examine a possible application of the (1→3)-β-D-glucan assay to monitor response to antifungal treatment in patients with Candida endocarditis.. The serum Fungitell assay was used to trend (1→3)-β-D-glucan in a patient with Candida endocarditis to determine treatment effectiveness with fluconazole, to provide an appropriate end date for antifungal therapy, and to survey infection suppression while off treatment.. The (1→03)-β-D-glucan assay began trending downwards at 197 days into treatment with oral fluconazole. After 16 months of therapy, fluconazole was stopped due to transaminitis. (1→3)-β-Dglucan levels were checked six weeks after the discontinuation of treatment and were negative. The patient has now been off therapy for 21 weeks with no signs of clinical disease, and values remain negative.. The present case indicates that a trending (1→3)-β-D-glucan assay may have valuable application in monitoring treatment response and infection suppression for Candida endocarditis.

Topics: Aged; Antifungal Agents; beta-Glucans; Biomarkers; Candida glabrata; Candidiasis; Drug Monitoring; Endocarditis; Female; Fluconazole; Humans; Predictive Value of Tests; Proteoglycans; Time Factors; Treatment Outcome

Diagnosis of pneumocystis pneumonia (PCP) relies on microscopic visualization of P. jirovecii, or detection of Pneumocystis DNA in respiratory specimens, which involves invasive procedures such as bronchoalveolar lavage. The (1-3)-β-D-glucan (BG) assay has been proposed as a less invasive and less expensive diagnostic test to rule out PCP. We therefore compared blood levels of BG in patients with PCP with those of patients with candidemia, chronic disseminated candidiasis (CDC), invasive aspergillosis, mucormycosis, and tuberculosis and those of healthy volunteers.. Adult patients who were diagnosed with PCP, candidemia, CDC, invasive aspergillosis, mucormycosis, and tuberculosis whose blood samples were available, and healthy volunteers were enrolled in a tertiary hospital in Seoul, South Korea, during a 21-month period. The blood samples were assayed with the Goldstream Fungus (1-3)-β-D-glucan test (Gold Mountain River Tech Development, Beijing, China).. A total of 136 individuals including 50 patients P. jirovecii,15 candidemia, 6 CDC, 15 invasive aspergillosis, 10 mucormycosis, and 40 controls (20 TB and 20 healthy volunteers) were included. The mean±SD of the concentration of 1-3-β-D-glucan in the patients with PCP (290.08 pg/mL±199.98) were similar to those of patients with candidemia (314.14 pg/mL±205.60, p = 0.90 at an α = 0.005) and CDC (129.74 pg/mL±182.79, p = 0.03 at an α = 0.005), but higher than those of patients with invasive aspergillosis (131.62 pg/mL±161.67, p = 0.002 at an α = 0.005), mucormycosis (95.08 pg/mL±146.80, p<0.001 at an α = 0.005), and tuberculosis (103.31 pg/mL±140.81, p<0.001 at an α = 0.005) as well as healthy volunteers (101.18 pg/mL±197.52, p<0.001 at an α = 0.005). At a cut-off value > 31.25 pg/mL, which is highly sensitive for PCP versus tuberculosis plus healthy volunteers at the expense of specificity, the BG assay had a sensitivity of 92% (95% CI 81%-98%) and a specificity of 55% (95% CI 39%-71%).. The BG assay appears to be a useful adjunct test for PCP.

Topics: Adult; Aged; Aspergillosis; beta-Glucans; Candidiasis; Case-Control Studies; Diagnosis, Differential; Female; Healthy Volunteers; Humans; Male; Middle Aged; Mucormycosis; Pneumocystis carinii; Pneumonia, Pneumocystis; Republic of Korea; Tuberculosis, Pulmonary

Fungal infections of the central nervous system (FICNS) are important causes of morbidity and mortality among immunocompromised pediatric patients. Standard diagnostic modalities lack the sensitivity for detecting and therapeutically monitoring these life-threatening diseases. Current molecular methods remain investigational. (1→3)-β-d-glucan (BDG) is a cell wall component found in several fungal pathogens, including Candida and Aspergillus spp. Detecting BDG in cerebrospinal fluid (CSF) may be an important approach for detecting and therapeutically monitoring FICNS. To date, there has been no study that has investigated the effectiveness of CSF BDG as a diagnostic and therapeutic marker of FICNS in children.. Serial BDG levels were measured in serum and CSF samples obtained from pediatric patients (aged 0-18 years) with a diagnosis of probable or proven Candida or Aspergillus CNS infection.. Nine cases of FICNS were identified in patients aged 1 month to 18 years. Two patients were infected with an Aspergillus species, and 7 patients were infected with a Candida species. All the patients at baseline had detectable BDG in their CSF. Among 7 patients who completed therapy for an FICNS, all elevated CSF BDG levels decreased to <31 pg/mL. At the time of this writing, 1 patient was still receiving therapy and continued to have elevated BDG levels. One patient died from overwhelming disseminated candidiasis. The lengths of therapy for these 9 children ranged from 2 weeks to 28 months.. The BDG assay is useful in diagnosing and therapeutically monitoring Candida and Aspergillus CNS infections in pediatric patients.

Topics: Aspergillosis; beta-Glucans; Biomarkers; Candida; Candidiasis; Central Nervous System Fungal Infections; Child; Humans; Nervous System; Proteoglycans

The in vitro activity of posaconazole (PSC) and voriconazole (VRC) was tested by using time-kill studies against 3 strains of Candida lusitaniae. Both drugs showed fungistatic activity against all strains. The efficacy of those compounds was evaluated by reducing kidney fungal burden and by determining (1→3)-β-d-glucan serum levels in a murine model of invasive infection of C. lusitaniae. The therapies tested were VRC at 10, 25, or 40 mg/kg/day and PSC at 5, 12.5, or 20 mg/kg/twice a day. All the dosages showed efficacy in a dose-dependant manner being high doses of both antifungals able to sterilize some kidneys after 10 days. With the exception of the strain FMR 9474, against which PSC was more effective than VRC, no differences in reducing tissue burden were found between the treatments. All doses of both antifungals were able to significantly reduce (1→3)-β-d-glucan serum levels with no significant differences between treatments and between the same doses of both drugs.

Topics: Animals; Antifungal Agents; beta-Glucans; Candida; Candidiasis; Colony Count, Microbial; Disease Models, Animal; Dose-Response Relationship, Drug; Humans; Kidney; Male; Mice; Proteoglycans; Treatment Outcome; Triazoles; Voriconazole

Candidiasis has posed a serious health risk to immunocompromised patients owing to the increase in resistant yeasts, and Candida albicans is the prominent pathogen of fungal infections. Therefore, there is a critical need for the discovery and characterization of novel antifungals to treat infections caused by C. albicans. In the present study, we report on the antifungal activity of the ethanol extract from Salvia miltiorrhiza against C. albicans and the possible mode of action against C. albicans. The increase in the membrane permeability was evidenced by changes in diphenylhexatriene binding and release of both 260-nm-absorbing intracellular materials and protein. In addition, inhibition of cell wall synthesis was demonstrated by the enhanced minimal inhibitory concentration in the presence of sorbitol and reduced (1,3)-β-D-glucan synthase activity. The above evidence supports the notion that S. miltiorrhiza has antifungal activity against C. albicans by the synergistic activity of targeting the cell membrane and cell wall. These findings indicate that S. miltiorrhiza displays effective activity against C. albicans in vitro and merits further investigation to treat C. albicans-associated infections.

Topics: Antifungal Agents; beta-Glucans; Candida albicans; Candidiasis; Cell Membrane Permeability; Cell Wall; Fungal Proteins; Glucosyltransferases; Humans; Microbial Sensitivity Tests; Proteoglycans; Salvia miltiorrhiza

The Cek1 MAP kinase (MAPK) mediates vegetative growth and cell wall biogenesis in the fungal pathogen Candida albicans. Alterations in the fungal cell wall caused by a defective Cek1‑mediated signaling pathway leads to increased β‑1,3‑glucan exposure influencing dectin‑1 fungal recognition by immune cells. We show here that cek1 cells also display an increased exposure of α‑1,2 and β‑1,2‑mannosides (α‑M and β‑M), a phenotype shared by strains defective in the activating MAPKK Hst7, suggesting a general defect in cell wall assembly. cek1 cells display walls with loosely bound material as revealed by transmission electron microscopy and are sensitive to tunicamycin, an inhibitor of N‑glycosylation. Transcriptomal analysis of tunicamycin treated cells revealed a differential pattern between cek1 and wild type cells which involved mainly cell wall and stress related genes. Mapping α‑M and β‑M epitopes in the mannoproteins of different cell wall fractions (CWMP) revealed an important shift in the molecular weight of the mannan derived from mutants defective in this MAPK pathway. We have also assessed the role of galectin‑3, a member of a β‑galactoside‑binding protein family shown to bind to and kill C. albicans through β‑M recognition, in the infection caused by cek1 mutants. Increased binding of cek1 to murine macrophages was shown to be partially blocked by lactose. Galectin-3(-/-) mice showed increased resistance to fungal infection, although galectin-3 did not account for the reduced virulence of cek1 mutants in a mouse model of systemic infection. All these data support a role for the Cek1‑mediated pathway in fungal cell wall maintenance, virulence and antifungal discovery.

Topics: Animals; beta-Glucans; Candida albicans; Candidiasis; Cell Wall; Disease Models, Animal; Fungal Proteins; Galectin 3; Gene Expression Profiling; Gene Expression Regulation, Fungal; Mannosides; MAP Kinase Signaling System; Mice; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Mutation; Tunicamycin; Virulence

Pathogens hide immunogenic epitopes from the host to evade immunity, persist and cause infection. The opportunistic human fungal pathogen Candida albicans, which can cause fatal disease in immunocompromised patient populations, offers a good example as it masks the inflammatory epitope β-glucan in its cell wall from host recognition. It has been demonstrated previously that β-glucan becomes exposed during infection in vivo but the mechanism behind this exposure was unknown. Here, we show that this unmasking involves neutrophil extracellular trap (NET) mediated attack, which triggers changes in fungal cell wall architecture that enhance immune recognition by the Dectin-1 β-glucan receptor in vitro. Furthermore, using a mouse model of disseminated candidiasis, we demonstrate the requirement for neutrophils in triggering these fungal cell wall changes in vivo. Importantly, we found that fungal epitope unmasking requires an active fungal response in addition to the stimulus provided by neutrophil attack. NET-mediated damage initiates fungal MAP kinase-driven responses, particularly by Hog1, that dynamically relocalize cell wall remodeling machinery including Chs3, Phr1 and Sur7. Neutrophil-initiated cell wall disruptions augment some macrophage cytokine responses to attacked fungi. This work provides insight into host-pathogen interactions during disseminated candidiasis, including valuable information about how the C. albicans cell wall responds to the biotic stress of immune attack. Our results highlight the important but underappreciated concept that pattern recognition during infection is dynamic and depends on the host-pathogen dialog.

Topics: Animals; Antigens, Fungal; beta-Glucans; Candida albicans; Candidiasis; Cell Wall; Disease Models, Animal; Extracellular Traps; Female; HEK293 Cells; Host-Pathogen Interactions; Humans; Image Processing, Computer-Assisted; Immune Evasion; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Fluorescence; Neutrophils

The ß-D-glucan assay (BDG) has been added to the EORTC/MSG criteria for the diagnosis of invasive fungal infections (IFI), but data from pediatric populations is scarce. The aim of this study was to evaluate performance of BDG in a cohort of hemato-oncological children with hematological malignancy at risk for IFI.. 113 patients were included through an 18-month period. In addition to routine IFI screening, BDG was assayed once a week. IFIs were classified using EORTC/MSG criteria without including the BDG results. Performances were assessed after a ROC analysis for optimization and multivariate analysis to detect the causes of false positivity.. 8 proven and 4 probable IFIs, and 7 possible IFIs were diagnosed in 9 and 7 patients, respectively. Sensitivity and specificity increased from 75% and 56% to 100% and 91.1%, respectively when considering the whole population and patients not having received any antifungals prior to the test. Multivariate analysis revealed that being younger than 7, severe colitis/mucositis, recent administration of polyvalent immunoglobulins and digestive colonization with Enterococcus sp were independent risk factors for false positivity.. BDG is a valuable test to detect IFI in pediatric patients not previously treated with antifungals and to detect the occurrence of chronic infection.

Topics: Adolescent; beta-Glucans; Candida; Candidiasis; Child; Child, Preschool; Female; Hematologic Neoplasms; Humans; Infant; Invasive Fungal Infections; Male; Predictive Value of Tests; Reagent Kits, Diagnostic; ROC Curve; Sensitivity and Specificity

A 44-year-old female presented with a 3-month history of headache, dizziness, nausea, and vomiting. Her past medical history was significant for long-standing intravenous drug abuse. Shortly after admission, the patient became hypertensive and febrile, with fever as high as 38.8°C. The lumbar puncture profile supported an infectious process; however multiple cultures of blood and cerebrospinal fluid (CSF) did not initially show growth of organisms. Finally after 9 days of incubation, a CSF culture showed evidence of a few colonies of Candida albicans. To confirm the diagnosis, preserved CSF from that sample was tested for (1→3)-β-d-glucan, showing levels >500pg/ml. This report illustrates a rare complication of intravenous drug use in an immunocompetent patient and demonstrates the utility of (1→3)-β-d-glucan testing in possible Candida meningitis.

Topics: Adult; beta-Glucans; Candida albicans; Candidiasis; Female; Humans; Immunocompetence; Meningitis, Fungal; Substance Abuse, Intravenous

With the rapid growth in fungal infections and drug-resistant fungal strains, antifungal vaccines have become an especially attractive strategy to tackle this important health problem. β-Glucans, a class of extracellular carbohydrate antigens abundantly and consistently expressed on fungal cell surfaces, are intriguing epitopes for antifungal vaccine development. β-Glucans have a conserved β-1,3-glucan backbone with sporadic β-1,3- or β-1,6-linked short glucans as branches at the 6-O-positions, and the branches may play a critical role in their immunologic functions. To study the immunologic properties of branched β-glucans and develop β-glucan-based antifungal vaccines, three branched β-glucan oligosaccharides with 6-O-linked β-1,6-tetraglucose, β-1,3-diglucose, and β-1,3-tetraglucose branches on a β-1,3-nonaglucan backbone, which mimic the structural epitopes of natural β-glucans, were synthesized and coupled with keyhole limpet hemocyanin (KLH) to form novel synthetic conjugate vaccines. These glycoconjugates were proved to elicit strong IgG antibody responses in mice. It was also discovered that the number, size, and structure of branches linked to the β-glucan backbone had a significant impact on the immunologic property. Moreover, antibodies induced by the synthetic oligosaccharide-KLH conjugates were able to recognize and bind to natural β-glucans and fungal cells. Most importantly, these conjugates elicited effective protection against systemic Candida albicans infection in mice. Thus, branched oligo-β-glucans were identified as functional epitopes for antifungal vaccine design and the corresponding protein conjugates as promising antifungal vaccine candidates.

Topics: Animals; Antibody Formation; beta-Glucans; Candida albicans; Candidiasis; Disease Models, Animal; Drug Discovery; Female; Fungal Vaccines; Immunoglobulin G; Mice; Mice, Inbred C57BL; Oligosaccharides; Vaccines, Conjugate

Microbiological documentation of peritoneal candidiasis (PC) is hampered by the low numbers of yeasts observable by direct microscopic examination and recoverable by culture methods. The performance of a polymerase chain reaction (PCR) DNA Low-Density Microarray System (CLART STIs B) was compared to that of BACTEC FX automated culture method for the detection of Candida spp. in 161 peritoneal fluids (PF) from patients with peritonitis. The clinical utility of (1-3)-β-d-glucan (BDG) antigenemia in the diagnosis of PC was evaluated in 42 of these patients. The overall agreement between the PCR assay and the culture method was good (κ = 0.790), and their sensitivities were 93.5% and 74.19%, respectively. Serum BDG levels in patients with Candida spp. in PFs (median, 200.3 pg/mL; Range, 22.0-523.4 pg/mL) was significantly higher (P = 0.002) than those found in patients without the yeast (median, 25.3 pg/mL; Range, 0-523.4 pg/mL). Our study demonstrates the potential clinical utility of molecular methods and the measurement of serum BDG levels for the diagnosis of PC.

Topics: Adult; Aged; Aged, 80 and over; Ascitic Fluid; beta-Glucans; Candidiasis; DNA, Fungal; Female; Humans; Male; Microarray Analysis; Middle Aged; Peritoneal Cavity; Peritonitis; Polymerase Chain Reaction; Proteoglycans; Sensitivity and Specificity; Serum; Young Adult

Antifungal vaccines have recently engendered considerable excitement for counteracting the resurgence of fungal infections. In this context, β-glucan, which is abundantly expressed on all fungal cell surfaces, functionally necessary for fungi, and immunologically active, is an attractive target antigen. Aiming at the development of effective antifungal vaccines based on β-glucan, a series of its oligosaccharide derivatives was designed, synthesized, and coupled with a carrier protein, keyhole limpet hemocyanin (KLH), to form new semisynthetic glycoconjugate vaccines. In this article, a convergent and effective synthetic strategy using preactivation-based iterative glycosylation was developed for the designed oligosaccharides. The strategy can be widely useful for rapid construction of large oligo-β-glucans with shorter oligosaccharides as building blocks. The KLH conjugates of the synthesized β-glucan hexa-, octa-, deca-, and dodecasaccharides were demonstrated to elicit high titers of antigen-specific total and IgG antibodies in mice, suggesting the induction of functional T cell-mediated immunity. Moreover, it was revealed that octa-, deca-, and dodeca-β-glucans were much more immunogenic than the hexamer and that the octamer was the best among these. The results suggested that the optimal oligosaccharide sequence of β-glucan required for exceptional immunogenicity was a hepta- or octamer and that longer glucans are not necessarily better antigens, a finding that may be of general importance. Most importantly, the octa-β-glucan-KLH conjugate provoked protective immunity against Candida albicans infection in a systemic challenge model in mice, suggesting the great potential of this glycoconjugate as a clinically useful immunoprophylactic antifungal vaccine.

Topics: Animals; Antifungal Agents; Antigens, Fungal; beta-Glucans; Candida albicans; Candidiasis; Drug Discovery; Female; Fungal Vaccines; Mice; Mice, Inbred C57BL; Oligosaccharides

Colonization of patients occurs before development into invasive candidiasis. There is a need to determine the incidences of Candida colonization and infection in SICU patients, and evaluate the usefulness of beta-D-glucan (BDG) assay in diagnosing invasive candidiasis when patients are colonized.. Clinical data and fungal surveillance cultures in 28 patients were recorded from November 2010, and January to February 2011. Susceptibilities of Candida isolates to fluconazole, voriconazole, amphotericin B, micafungin, caspofungin and anidulafungin were tested via Etest. The utilities of BDG, Candida score and colonization index for candidiasis diagnosis were compared via ROC.. 30 BDG assays were performed in 28 patients. Four assay cases had concurrent colonization and infection; 23 had concurrent colonization and no infection; three had no concurrent colonization and infection. Of 136 surveillance swabs, 52 (38.24 %) were positive for Candida spp, with C. albicans being the commonest. Azole resistance was detected in C. albicans (7 %). C. glabrata and C. tropicalis were, respectively, 100 and 7 % SDD to fluconazole. All 3 tests showed high sensitivity of 75-100 % but poor specificity ranging 15.38-38.46 %. BDG performed the best (AUC of 0.89).. Despite that positive BDG is common in surgical patients with Candida spp colonization, BDG performed the best when compared to CI and CS.

Topics: Adult; Aged; Aged, 80 and over; Amphotericin B; Anidulafungin; Antifungal Agents; beta-Glucans; Candida; Candida albicans; Candida glabrata; Candidiasis; Candidiasis, Invasive; Carrier State; Caspofungin; Critical Care; Echinocandins; Female; Fluconazole; Humans; Incidence; Intensive Care Units; Lipopeptides; Male; Micafungin; Microbial Sensitivity Tests; Middle Aged; Sensitivity and Specificity; Singapore; Tertiary Care Centers; Voriconazole

Candida lusitaniae is usually susceptible to echinocandins. Beta-1,3-glucan synthase encoded by FKS genes is the target of echinocandins. A few missense mutations in the C. lusitaniae FKS1 hot spot 1 (HS1) have been reported. We report here the rapid emergence of antifungal resistance in C. lusitaniae isolated during therapy with amphotericin B (AMB), caspofungin (CAS), and azoles for treatment of persistent candidemia in an immunocompromised child with severe enterocolitis and visceral adenoviral disease. As documented from restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD) analysis, the five C. lusitaniae isolates examined were related to each other. From antifungal susceptibility and molecular analyses, 5 different profiles (P) were obtained. These profiles included the following: profile 1 (P1) (CAS MIC [μg/ml], 0.5; fluconazole [FLC] MIC, 0.25), determined while the patient was being treated with liposomal AMB for 3 months; P2 (FLC MIC [μg/ml], 0.25; CAS MIC, 4), while the patient was being treated with CAS for 2 weeks; P3 (CAS MIC [μg/ml], 0.5; FLC MIC, 32), while the patient was being treated with azoles and CAS initially followed by azoles alone for a week; P4 (CAS MIC [μg/ml], 8; FLC MIC, 8), while the patient was being treated with both drugs for 3 weeks; and P5 (AMB MIC [μg/ml], 0.125; CAS MIC, 8), while the patient was being treated with AMB and FLC for 2 weeks. CAS resistance was associated with resistance not only to micafungin and anidulafungin but also to AMB. Analysis of CAS resistance revealed 3 novel FKS1 mutations in CAS-resistant isolates (S638Y in P2; S631Y in P4; S638P in P5). While S638Y and -P are within HS1, S631Y is in close proximity to this domain but was confirmed to confer candin resistance using a site-directed mutagenesis approach. FLC resistance could be linked with overexpression of major facilitator gene 7 (MFS7) in C. lusitaniae P2 and P4 and was associated with resistance to 5-flurocytosine. This clinical report describes resistance of C. lusitaniae to all common antifungals. While candins or azole resistance followed monotherapy, multidrug antifungal resistance emerged during combined therapy.

Topics: Amino Acid Sequence; Antifungal Agents; beta-Glucans; Candida; Candidiasis; DNA, Fungal; Drug Monitoring; Drug Resistance, Multiple, Fungal; Female; Galactose; Humans; Immunocompromised Host; Infant; Leukemia, Myeloid, Acute; Mannans; Microbial Sensitivity Tests; Molecular Sequence Data; Mutation; Polymorphism, Restriction Fragment Length

The clinical success of the echinocandins, which can only be administered parentally, has validated β-1,3-glucan synthase (GS) as an antifungal target. Semi-synthetic modification of enfumafungin, a triterpene glycoside natural product, was performed with the aim of producing a new class of orally active GS inhibitors. Replacement of the C2 acetoxy moiety with various heterocycles did not improve GS or antifungal potency. However, replacement of the C3 glycoside with an aminoether moiety dramatically improved oral pharmacokinetic (PK) properties while maintaining GS and antifungal potency. Installing an aminotetrazole at C2 in conjunction with an N-alkylated aminoether at C3 produced derivatives with significantly improved GS and antifungal potency that exhibited robust oral efficacy in a murine model of disseminated candidiasis.

Topics: Administration, Oral; Animals; Antifungal Agents; Aspergillus fumigatus; beta-Glucans; Candida albicans; Candidiasis; Glucosyltransferases; Glycosides; Half-Life; Mice; Microbial Sensitivity Tests; Structure-Activity Relationship; Terpenes; Triterpenes

The current standard of treatment of invasive candidiasis with echinocandins requires once-daily therapy. To improve quality of life, reduce costs, and improve outcome, we studied the pharmacokinetics (PK), efficacy, and safety of alternate dosing regimens of micafungin (MFG) for the treatment of experimental subacute disseminated candidiasis.. MFG was administered for 12 days starting 24 hours after intravenous inoculation of 1 × 10(3) Candida albicans blastoconidia. Study groups consisted of MFG at 1 mg/kg every 24 hours (MFG1), 2 mg/kg every 48 hours (MFG2), and 3 mg/kg every 72 hours (MFG3), and untreated controls. PK of MFG were determined on day 7 by high-performance liquid chromatography and modeled using nonparametric adaptive grid program. A 2-compartment PK model with volume of the central compartment (Vc), clearance (SCL), and the intercompartmental rate constants Kcp and Kpc was used. The fungal burden in 7 tissues was determined 312 hours after the initiation of therapy.. PK of MFG were linear and the parameter means ± SD were Vc = 0.41 ± 0.18 L, Kcp = 2.80 ± 1.55/hour, Kpc = 1.71 ± 0.93/hour, and SCL = 0.16 ± 0.003 L/hour (r(2) = 0.99). The area under the plasma drug concentration - time curve for MFG1, MFG2, and MFG3 was 198.7 ± 19.8, 166.3 ± 36.7, and 192.8 ± 46.2 mg × hour/L, respectively (P = .24). All treatment groups showed significant and comparable resolution of (1→3)-β-D-glucan levels and clearance of C. albicans from liver, spleen, kidney, brain, lung, vitreous humor, and vena cava in comparison to untreated controls (P ≤ .05). There were no differences in hepatic or renal function among study groups.. Less fractionated MFG regimens of every 48 and 72 hours are safe and as effective in experimental disseminated candidiasis as once-daily therapy in neutropenic hosts.

Topics: Animals; Antifungal Agents; beta-Glucans; Candida albicans; Candidiasis; Candidiasis, Invasive; Colony Count, Microbial; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Echinocandins; Female; Lipopeptides; Micafungin; Neutropenia; Proteoglycans; Rabbits

Inflammasomes are central mediators of host defense to a wide range of microbial pathogens. The nucleotide-binding domain and leucine-rich repeat containing family (NLR), pyrin domain-containing 3 (NLRP3) inflammasome plays a key role in triggering caspase-1-dependent IL-1β maturation and resistance to fungal dissemination in Candida albicans infection. β-Glucans are major components of fungal cell walls that trigger IL-1β secretion in both murine and human immune cells. In this study, we sought to determine the contribution of β-glucans to C. albicans-induced inflammasome responses in mouse dendritic cells. We show that the NLRP3-apoptosis-associated speck-like protein containing caspase recruitment domain protein-caspase-1 inflammasome is absolutely critical for IL-1β production in response to β-glucans. Interestingly, we also found that both complement receptor 3 (CR3) and dectin-1 play a crucial role in coordinating β-glucan-induced IL-1β processing as well as a cell death response. In addition to the essential role of caspase-1, we identify an important role for the proapoptotic protease caspase-8 in promoting β-glucan-induced cell death and NLRP3 inflammasome-dependent IL-1β maturation. A strong requirement for CR3 and caspase-8 also was found for NLRP3-dependent IL-1β production in response to heat-killed C. albicans. Taken together, these results define the importance of dectin-1, CR3, and caspase-8, in addition to the canonical NLRP3 inflammasome, in mediating β-glucan- and C. albicans-induced innate responses in dendritic cells. Collectively, these findings establish a novel link between β-glucan recognition receptors and the inflammatory proteases caspase-8 and caspase-1 in coordinating cytokine secretion and cell death in response to immunostimulatory fungal components.

Topics: Animals; beta-Glucans; Candida albicans; Candidiasis; Carrier Proteins; Caspase 8; Cell Death; Dendritic Cells; Fungal Polysaccharides; Humans; Interleukin-1beta; Lectins, C-Type; Macrophage-1 Antigen; Mice; Mice, Knockout; NLR Family, Pyrin Domain-Containing 3 Protein

A mouse anti-anti-anti-idiotypic (Id) IgM monoclonal antibody (mAb K20, Ab4), functionally mimicking a Wyckerhamomyces anomalus (Pichia anomala) killer toxin (KT) characterized by fungicidal activity against yeasts presenting specific cell wall receptors (KTR) mainly constituted by β-1,3-glucan, was produced from animals presenting anti-KT Abs (Ab3) following immunization with a rat IgM anti-Id KT-like mAb (mAb K10, Ab2). MAb K10 was produced by immunization with a KT-neutralizing mAb (mAb KT4, Ab1) bearing the internal image of KTR. MAb K20, likewise mAb K10, proved to be fungicidal in vitro against KT-sensitive Candida albicans cells, an activity neutralized by mAb KT4, and was capable of binding to β-1,3-glucan. MAb K20 and mAb K10 competed with each other and with KT for binding to C. albicans KTR. MAb K20 was used to identify peptide mimics of KTR by the selection of phage clones from random peptide phage display libraries. Using this strategy, four peptides (TK 1-4) were selected and used as immunogen in mice in the form of either keyhole limpet hemocyanin (KLH) conjugates or peptide-encoding minigenes. Peptide and DNA immunization could induce serum Abs characterized by candidacidal activity, which was inhibited by laminarin, a soluble β-1,3-glucan, but not by pustulan, a β-1,6-glucan. These findings show that the idiotypic cascade can not only overcome the barrier of animal species but also the nature of immunogens and the type of technology adopted.

Topics: Amino Acid Sequence; Animals; Antibodies, Anti-Idiotypic; beta-Glucans; Candida albicans; Candidiasis; Fungal Proteins; Fungal Vaccines; Hemocyanins; Killer Factors, Yeast; Mice; Molecular Mimicry; Molecular Sequence Data; Mycotoxins; Peptide Library; Peptides; Pichia; Rats; Receptors, Cell Surface; Vaccination; Vaccines, DNA; Vaccines, Subunit

Emerging evidence indicates that innate immunodeficiency syndromes are linked to mutations in innate receptors and to specific infections. X-linked lymphoproliferative syndrome type-2 (XLP-2) is associated with deficiency in X-linked inhibitor of apoptosis protein (XIAP), with poorly understood molecular mechanisms. Here we showed that XIAP deficiency selectively impaired B-cell chronic lymphocytic leukemia/lymphoma 10 (BCL10)-mediated innate responses to dectin-1 ligands but did not affect responses to various Toll-like receptor agonists. Consequently, Xiap(-/-) mice became highly vulnerable on Candida albicans infection. The compromised early innate responses led to the persistent presence of C albicans and inflammatory cytokines in Xiap(-/-) mice. Furthermore, priming of Xiap(-/-) mice with the dectin-1 ligand curdlan alone resulted in XLP-2-like syndromes. Restoration of dectin-1-induced Rac1 activation and phagocytosis by resolvin D1, but not up-regulation of nuclear factor-κB, rescued Xiap(-/-) mice from C albicans lethal infection. Therefore, development of XLP-2 in XIAP-deficient patients could be partly due to sustained inflammation as a consequence of defective BCL10-dependent innate immunity toward specific pathogens. Importantly, our results suggest the potential therapeutic value of resolvin D1 in the treatment of XLP-2 and innate immunodeficiency syndromes.

Topics: Adaptor Proteins, Signal Transducing; Animals; B-Cell CLL-Lymphoma 10 Protein; beta-Glucans; Candida albicans; Candidiasis; ErbB Receptors; Genetic Diseases, X-Linked; Humans; Imidazoles; Immunity, Innate; Inhibitor of Apoptosis Proteins; Lectins, C-Type; Lipopeptides; Lipopolysaccharides; Lymphoproliferative Disorders; Lysine; Lysophospholipids; Macrophages; Mice; NF-kappa B; Phagocytosis; Poly I-C; Protein Binding; Receptors, Antigen, T-Cell; Toll-Like Receptors; Tumor Necrosis Factor-alpha; Ubiquitination

Epigenetic reprogramming of myeloid cells, also known as trained immunity, confers nonspecific protection from secondary infections. Using histone modification profiles of human monocytes trained with the Candida albicans cell wall constituent β-glucan, together with a genome-wide transcriptome, we identified the induced expression of genes involved in glucose metabolism. Trained monocytes display high glucose consumption, high lactate production, and a high ratio of nicotinamide adenine dinucleotide (NAD(+)) to its reduced form (NADH), reflecting a shift in metabolism with an increase in glycolysis dependent on the activation of mammalian target of rapamycin (mTOR) through a dectin-1-Akt-HIF-1α (hypoxia-inducible factor-1α) pathway. Inhibition of Akt, mTOR, or HIF-1α blocked monocyte induction of trained immunity, whereas the adenosine monophosphate-activated protein kinase activator metformin inhibited the innate immune response to fungal infection. Mice with a myeloid cell-specific defect in HIF-1α were unable to mount trained immunity against bacterial sepsis. Our results indicate that induction of aerobic glycolysis through an Akt-mTOR-HIF-1α pathway represents the metabolic basis of trained immunity.

Topics: Aerobiosis; Animals; beta-Glucans; Candida albicans; Candidiasis; Disease Models, Animal; Epigenesis, Genetic; Female; Glucose; Glycolysis; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Immunity, Innate; Immunologic Memory; Male; Mice; Mice, Inbred C57BL; Monocytes; Sepsis; Staphylococcal Infections; Staphylococcus aureus; TOR Serine-Threonine Kinases; Transcriptome

Dectin-1 functions as a pattern recognition receptor for sensing fungal infection. It has been well-established that Dectin-1 induces innate immune responses through caspase recruitment domain-containing protein 9 (CARD9)-mediated NF-κB activation. In this study, we find that CARD9 is dispensable for NF-κB activation induced by Dectin-1 ligands, such as curdlan or Candida albicans yeast. In contrast, we find that CARD9 regulates H-Ras activation by linking Ras-GRF1 to H-Ras, which mediates Dectin-1-induced extracellular signal-regulated protein kinase (ERK) activation and proinflammatory responses when stimulated by their ligands. Mechanistically, Dectin-1 engagement initiates spleen tyrosine kinase (Syk)-dependent Ras-GRF1 phosphorylation, and the phosphorylated Ras-GRF1 recruits and activates H-Ras through forming a complex with CARD9, which leads to activation of ERK downstream. Finally, we show that inhibiting ERK activation significantly accelerates the death of C. albicans-infected mice, and this inhibitory effect is dependent on CARD9. Together, our studies reveal a molecular mechanism by which Dectin-1 induces H-Ras activation that leads to ERK activation for host innate immune responses against fungal infection.

Topics: Animals; beta-Glucans; Candida albicans; Candidiasis; CARD Signaling Adaptor Proteins; Enzyme Activation; Extracellular Signal-Regulated MAP Kinases; Female; Fungi; Humans; Immunity, Innate; Lectins, C-Type; Mice; Mice, Knockout; Multiprotein Complexes; Mycoses; NF-kappa B; Protein Binding; ras Proteins; ras-GRF1; Signal Transduction

Life-threatening intraabdominal candidiasis (IAC) occurs in 30 to 40% of high-risk surgical intensive care unit (ICU) patients. Although early IAC diagnosis is crucial, blood cultures are negative, and the role of Candida score/colonization indexes is not established.. The aim of this prospective Fungal Infection Network of Switzerland (FUNGINOS) cohort study was to assess accuracy of 1,3-β-d-glucan (BG) antigenemia for diagnosis of IAC.. Four hundred thirty-four consecutive adults with abdominal surgery or acute pancreatitis and ICU stay 72 hours or longer were screened: 89 (20.5%) at high risk for IAC were studied (68 recurrent gastrointestinal tract perforation, 21 acute necrotizing pancreatitis). Diagnostic accuracy of serum BG (Fungitell), Candida score, and colonization indexes was compared.. Fifty-eight of 89 (65%) patients were colonized by Candida; 29 of 89 (33%) presented IAC (27 of 29 with negative blood cultures). Nine hundred twenty-one sera were analyzed (9/patient): median BG was 253 pg/ml (46-9,557) in IAC versus 99 pg/ml (8-440) in colonization (P < 0.01). Sensitivity and specificity of two consecutive BG measurements greater than or equal to 80 pg/ml were 65 and 78%, respectively. In recurrent gastrointestinal tract perforation it was 75 and 77% versus 90 and 38% (Candida score ≥ 3), 79 and 34% (colonization index ≥ 0.5), and 54 and 63% (corrected colonization index ≥ 0.4), respectively. BG positivity anticipated IAC diagnosis (5 d) and antifungal therapy (6 d). Severe sepsis/septic shock and death occurred in 10 of 11 (91%) and 4 of 11 (36%) patients with BG 400 pg/ml or more versus 5 of 18 (28%, P = 0.002) and 1 of 18 (6%, P = 0.05) with BG measurement less than 400 pg/ml. β-Glucan decreased in IAC responding to therapy and increased in nonresponse.. BG antigenemia is superior to Candida score and colonization indexes and anticipates diagnosis of blood culture-negative IAC. This proof-of-concept observation in strictly selected high-risk surgical ICU patients deserves investigation of BG-driven preemptive therapy.

Topics: Adult; Aged; Aged, 80 and over; beta-Glucans; Candidiasis; Cohort Studies; Colony Count, Microbial; Female; Humans; Intensive Care Units; Intestinal Perforation; Intraabdominal Infections; Male; Middle Aged; Pancreatitis, Acute Necrotizing; Prospective Studies; Recurrence; Sensitivity and Specificity; Young Adult

We have evaluated the in vitro activity of caspofungin against 36 wild-type strains of Candida parapsilosis sensu stricto using 3 techniques: broth microdilution, disk diffusion, and the determination of minimal fungicidal concentration (MFC). The first 2 methods showed a good in vitro activity of caspofungin, but the MFCs were ≥2 dilutions above their corresponding MICs. In a murine model of disseminated infection, we evaluated the efficacy of caspofungin at 5 mg/kg against 8 strains of C. parapsilosis representing different degrees of in vitro susceptibility (0.12-1 μg/mL). All the isolates responded to treatment and (1→3)-β-D-glucan levels were reduced in all the cases; however, the study revealed differences among isolates, since caspofungin reduced the tissue burden of mice infected with isolates with MICs ≤0.5 μg/mL but was less effective against those with MICs of 1 μg/mL.

Topics: Animals; beta-Glucans; Candida; Candidiasis; Caspofungin; Colony Count, Microbial; Disease Models, Animal; Echinocandins; Lipopeptides; Male; Mice; Microbial Sensitivity Tests; Proteoglycans; Treatment Outcome

Galectin-3 is a β-galactoside-binding animal lectin with diverse functions, including regulation of T helper (Th) 1 and Th2 responses. Current data indicate that galectin-3 expressed in dendritic cells (DCs) may be contributory. Th17 cells have emerged as critical inducers of tissue inflammation in autoimmune disease and important mediators of host defense against fungal pathogens, although little is known about galectin-3 involvement in Th17 development. We investigated the role of galectin-3 in the induction of Th17 immunity in galectin-3-deficient (gal3(-/-)) and gal3(+/+) mouse bone marrow-derived DCs. We demonstrate that intracellular galectin-3 negatively regulates Th17 polarization in response to the dectin-1 agonist curdlan (a β-glucan present on the cell wall of fungal species) and lipopolysaccharide, agents that prime DCs for Th17 differentiation. On activation of dectin-1, gal3(-/-) DCs secreted higher levels of the Th17-axis cytokine IL-23 compared with gal3(+/+) DCs and contained higher levels of activated c-Rel, an NF-κB subunit that promotes IL-23 expression. Levels of active Raf-1, a kinase that participates in downstream inhibition of c-Rel binding to the IL23A promoter, were impaired in gal3(-/-) DCs. Modulation of Th17 by galectin-3 in DCs also occurred in vivo because adoptive transfer of gal3(-/-) DCs exposed to Candida albicans conferred higher Th17 responses and protection against fungal infection. We conclude that galectin-3 suppresses Th17 responses by regulating DC cytokine production.

Topics: Adoptive Transfer; Animals; beta-Glucans; Candida albicans; Candidiasis; Cell Polarity; Chickens; Cytokines; Dendritic Cells; Enzyme Activation; Extracellular Signal-Regulated MAP Kinases; Galectin 3; Immunity; Interleukin-23; Lectins, C-Type; Lipopolysaccharides; Mice; Mice, Inbred C57BL; Models, Biological; Proto-Oncogene Proteins c-raf; Proto-Oncogene Proteins c-rel; Signal Transduction; Th17 Cells

Topics: beta-Glucans; Brain Chemistry; Brain Diseases; Candida albicans; Candidiasis; Child, Preschool; Granuloma; Humans; Proteoglycans

Topics: beta-Glucans; Candidiasis; Female; Humans; Intraabdominal Infections; Male

The diagnosis of neonatal invasive Candida infections (ICIs) is problematic because the clinical signs are not specific and blood cultures are rarely positive. Hence, new diagnostic markers are needed.. To assess the contribution of serum (1-3)-β-d-glucan (BDG) levels to the diagnosis of neonatal ICIs and to analyse the change in this parameter during antifungal therapy.. This retrospective study (December 2010-March 2012) was performed at Amiens University Medical Center (Amiens, France). We included newborns in whom a BDG assay was performed for a suspected ICI and classified as infected (n = 18) or non-infected (n = 43).. Sixty-one patients (median (IQR) gestational age: 28.5 weeks (26.7-30.6); birth weight: 1000 g (910-1440)) were included. The BDG level was higher in the infected group (364 pg/ml (131-976) vs. 89 pg/ml (30-127); p < 0.001). The optimal BDG cut-off for distinguishing between non-infected and infected patients was 125 pg/ml (Se = 84%, Sp = 75%). The BDG level fell over the course of antifungal therapy.. Our study results suggest that BDG levels were increased in neonatal invasive Candida infections (cut-off for BDG positivity > 125 pg/ml). The change in the serum BDG levels may be of value in evaluating the efficacy of antifungal therapy.

Topics: Antifungal Agents; Bacteremia; beta-Glucans; Biomarkers; Candidiasis; Female; Humans; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Male; Pregnancy; Proteoglycans; Retrospective Studies

Limited data exist on Candida endocarditis (CE) outcome in the era of new antifungals. As early diagnosis of CE remains difficult, non-culture-based tools need to be evaluated. Through the French prospective MYCENDO study (2005-2007), the overall characteristics and risk factors for death from CE were analysed. The contribution of antigen detection (mannan/anti-mannan antibodies and (1,3)-β-d-glucans) and molecular tools was evaluated. Among 30 CE cases, 19 were caused by non-albicans species. Sixteen patients (53%) had a predisposing cardiac disease, which was a valvular prosthesis in ten (33%). Nine patients (30%) were intravenous drug users; none of them had right-sided CE. Among the 21 patients who were not intravenous drug users, 18 (86%) had healthcare-associated CE. Initial therapy consisted of a combination of antifungals in 12 of 30 patients (40%). Thirteen patients (43%) underwent valve replacement. The median follow-up was 1 year after discharge from hospital (range, 5 months to 4 years) and hospital mortality was 37%. On univariate analysis, patients aged ≥60 years had a higher mortality risk (OR 11, 95% CI 1.2-103.9; p 0.024), whereas intravenous drug use was associated with a lower risk of death (OR 0.12, 95% CI 0.02-0.7; p 0.03). Among 18 patients screened for both serum mannan/anti-mannan antibodies and (1,3)-β-d-glucans, all had a positive result with at least one of either test at CE diagnosis. Real-time PCR was performed on blood (SeptiFast) in 12 of 18, and this confirmed the blood culture results. In conclusion, CE prognosis remains poor, with a better outcome among younger patients and intravenous drug users. Detection of serum antigens and molecular tools may contribute to earlier CE diagnosis.

Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Antibodies, Fungal; Antifungal Agents; Antigens, Fungal; Aortic Valve; beta-Glucans; Candida; Candidiasis; Child; DNA, Fungal; Endocarditis; Female; Fluconazole; Follow-Up Studies; Humans; Kaplan-Meier Estimate; Male; Microbial Sensitivity Tests; Middle Aged; Prospective Studies; Proteoglycans; Risk Factors; Substance Abuse, Intravenous; Treatment Outcome; Young Adult

Fungal peritonitis is an unusual but severe complication of continuous peritoneal dialysis. The role of 1,3-β-D-glucan is unknown in early diagnosis and in treatment monitoring of peritoneal candidiasis. This case report shows the utility of 1,3-β-D-glucan monitoring in management of Candida peritonitis in a child undergoing continuous peritoneal dialysis.

Topics: Ascitic Fluid; beta-Glucans; Candidiasis; Child, Preschool; Drug Monitoring; Humans; Male; Peritoneal Dialysis; Peritonitis; Proteoglycans

The sensitivity of blood cultures for diagnosing invasive candidiasis (IC) is poor.. We performed a validated Candida real-time polymerase chain reaction (PCR) and the Fungitell 1,3-β-D-glucan (BDG) assay on blood samples collected from prospectively identified patients with IC (n = 55) and hospitalized controls (n = 73). Patients with IC had candidemia (n = 17), deep-seated candidiasis (n = 33), or both (n = 5). Controls had mucosal candidiasis (n = 5), Candida colonization (n = 48), or no known Candida colonization (n = 20).. PCR using plasma or sera was more sensitive than whole blood for diagnosing IC (P = .008). Plasma or sera PCR was more sensitive than BDG in diagnosing IC (80% vs 56%; P = .03), with comparable specificity (70% vs 73%; P = .31). The tests were similar in diagnosing candidemia (59% vs 68%; P = .77), but PCR was more sensitive for deep-seated candidiasis (89% vs 53%; P = .004). PCR and BDG were more sensitive than blood cultures among patients with deep-seated candidiasis (88% and 62% vs 17%; P = .0005 and .003, respectively). PCR and culture identified the same Candida species in 82% of patients. The sensitivity of blood cultures combined with PCR or BDG among patients with IC was 98% and 79%, respectively.. Candida PCR and, to a lesser extent, BDG testing significantly enhanced the ability of blood cultures to diagnose IC.

Topics: beta-Glucans; Candida; Candidemia; Candidiasis; Candidiasis, Invasive; DNA, Fungal; Humans; Prospective Studies; Proteoglycans; Reagent Kits, Diagnostic; Real-Time Polymerase Chain Reaction; Sensitivity and Specificity

We examined the effect of the oral administration of β-D-glucan derived from Aureobasidium pullulans ADK-34 (AP-FBG) on Candida albicans or methicillin-resistant Staphylococcus aureus (MRSA) infection in immunosuppressed mice. Mice pretreated with cyclophosphamide (CY) were intraperitoneally administered AP-FBG for 4 days and then infected with 6×10(4) C. albicans cells. In a preliminary experiment, the survival time of the Candida-infected mice treated with AP-FBG was clearly prolonged. Similarly, the effect of the oral administration of AP-FBG was examined. Mice were orally given 2.5% AP-FBG in feed for 42 days from 14 days prior to 2×10(4) C. albicans cells infection. The survival time of mice treated with AP-FBG was significantly prolonged and the viable cell count in the kidneys of the survivors was significantly decreased at 30 days after infection. The effects of the oral administration of AP-FBG on intestinal MRSA infection were also examined. Mice were given 2.5% AP-FBG orally in feed for 30 days before and after oral MRSA infection and treated with CY 12 days after the infection. The number of viable MRSA cells or the IgA production in feces did not significantly change, while AP-FBG administration seemed to relieve temporally the loss of body weight of mice.. These results suggest that oral pre-administration of AP-FBG promoted resistance of CY-treated mice to C. albicans and lessened the weight reduction of CY-mice infected by MRSA.

Topics: Administration, Oral; Animals; Ascomycota; beta-Glucans; Candidiasis; Cyclophosphamide; Immunocompromised Host; Immunosuppression Therapy; Life Support Care; Methicillin-Resistant Staphylococcus aureus; Mice; Staphylococcal Infections; Weight Loss

Ocular candidiasis is a major complication of Candida bloodstream infection (BSI). This study was performed to reveal the clinical characteristics of ocular candidiasis. Of the 220 patients with Candida BSI, 204 cases received ophthalmology consultations between January 2005 and December 2011 at 2 teaching hospitals. Fifty-four (26.5%) cases had findings consistent with the diagnosis of ocular candidiasis. Of these 54 cases, 43 (79.6%) were diagnosed within 7 days after a positive blood culture. Among ocular candidiasis cases, more cases were due to Candida albicans (P =0.034 odds ratio [OR]; 3.68 95% confidence interval [CI] 1.11-12.2) and had higher β-d-glucan values (P = 0.001 OR; 9.99 95% CI 2.60-21.3). We need to consider fundoscopic examination to be performed within the first 7 days of therapy, especially for those patients who have C. albicans BSIs and higher β-d-glucan values. Additionally, follow-up fundoscopic examination should be considered before stopping therapy for high-risk patients.

Topics: Adult; Aged; Aged, 80 and over; beta-Glucans; Candidemia; Candidiasis; Diagnostic Techniques, Ophthalmological; Eye Infections, Fungal; Female; Humans; Incidence; Male; Middle Aged; Multivariate Analysis; Odds Ratio; Risk Factors

We report findings for a 74-year-old woman with Candida tropicalis endophthalmitis for whom an increase in b-D-glucan level and worsening of endophthalmitis were observed after intravenous injection of micafungin, an echinocandin antifungal agent. Endogenous endophthalmitis caused by C. tropicalis developed in both eyes. On the basis of her surgical history, laboratory data,and lesions, tentative diagnosis of fungal endophthalmitis was made. She was then treated with fluconazole and itraconazole, but the b-D-glucan level did not decrease, and there was no improvement of the endophthalmitis. The fluconazole was discontinued and replaced by micafungin.Unexpectedly, the level of b-D-glucan increased and endophthalmitis did not improve. The micafungin was immediately stopped and replaced by intravenous fluconazole with amphotericin B syrup, but the itraconazole was continued. Marked resolution of the vitreous inflammation was observed in both eyes, and the serum b-D-glucan level was reduced. Because active macular infiltrates were observed in the right eye, vitrectomy was performed. The micafungin minimum inhibitory concentration against the C. tropicalis strain isolated from our patient was 0.03 lg/ml. This paradoxical effect of micafungin should be remembered, and b-D-glucan level should be frequently monitored after intravenous injection of micafungin.

Topics: Aged; Antifungal Agents; beta-Glucans; Candida tropicalis; Candidiasis; Echinocandins; Endophthalmitis; Female; Fundus Oculi; Humans; Itraconazole; Lipopeptides; Micafungin

Yeasts and their glycan components can have a beneficial or adverse effect on intestinal inflammation. Previous research has shown that the presence of Saccharomyces cerevisiae var. boulardii (Sb) reduces intestinal inflammation and colonization by Candida albicans. The aim of this study was to identify dietary yeasts, which have comparable effects to the anti-C. albicans and anti-inflammatory properties of Sb and to assess the capabilities of yeast cell wall components to modulate intestinal inflammation. Mice received a single oral challenge of C. albicans and were then given 1.5% dextran-sulphate-sodium (DSS) for 2 weeks followed by a 3-day restitution period. S. cerevisiae strains (Sb, Sc1 to Sc4), as well as mannoprotein (MP) and β-glucan crude fractions prepared from Sc2 and highly purified β-glucans prepared from C. albicans were used in this curative model, starting 3 days after C. albicans challenge. Mice were assessed for the clinical, histological and inflammatory responses related to DSS administration. Strain Sc1-1 gave the same level of protection against C. albicans as Sb when assessed by mortality, clinical scores, colonization levels, reduction of TNFα and increase in IL-10 transcription. When Sc1-1 was compared with the other S. cerevisiae strains, the preparation process had a strong influence on biological activity. Interestingly, some S. cerevisiae strains dramatically increased mortality and clinical scores. Strain Sc4 and MP fraction favoured C. albicans colonization and inflammation, whereas β-glucan fraction was protective against both. Surprisingly, purified β-glucans from C. albicans had the same protective effect. Thus, some yeasts appear to be strong modulators of intestinal inflammation. These effects are dependent on the strain, species, preparation process and cell wall fraction. It was striking that β-glucan fractions or pure β-glucans from C. albicans displayed the most potent anti-inflammatory effect in the DSS model.

Topics: Animals; Anti-Inflammatory Agents; beta-Glucans; Candida albicans; Candidiasis; Cell Wall; Complex Mixtures; Female; Interleukin-10; Intestinal Diseases; Intestines; Mice; Mice, Inbred BALB C; Saccharomyces cerevisiae; Tumor Necrosis Factor-alpha

Topics: Amphotericin B; Antifungal Agents; beta-Glucans; Biofilms; Biomarkers; Candida; Candidiasis; Catheterization, Central Venous; Drug Resistance, Fungal; Humans; Liposomes

Perception of external stimuli and generation of an appropriate response are crucial for host colonization by pathogens. In pathogenic fungi, mitogen activated protein kinase (MAPK) pathways regulate dimorphism, biofilm/mat formation, and virulence. Signaling mucins, characterized by a heavily glycosylated extracellular domain, a transmembrane domain, and a small cytoplasmic domain, are known to regulate various signaling pathways. In Candida albicans, the mucin Msb2 regulates the Cek1 MAPK pathway. We show here that Msb2 is localized to the yeast cell wall and is further enriched on hyphal surfaces. A msb2Δ/Δ strain formed normal hyphae but had biofilm defects. Cek1 (but not Mkc1) phosphorylation was absent in the msb2Δ/Δ mutant. The extracellular domain of Msb2 was shed in cells exposed to elevated temperature and carbon source limitation, concomitant with germination and Cek1 phosphorylation. Msb2 shedding occurred differentially in cells grown planktonically or on solid surfaces in the presence of cell wall and osmotic stressors. We further show that Msb2 shedding and Cek1 phosphorylation were inhibited by addition of Pepstatin A (PA), a selective inhibitor of aspartic proteases (Saps). Analysis of combinations of Sap protease mutants identified a sap8Δ/Δ mutant with reduced MAPK signaling along with defects in biofilm formation, thereby suggesting that Sap8 potentially serves as a major regulator of Msb2 processing. We further show that loss of either Msb2 (msb2Δ/Δ) or Sap8 (sap8Δ/Δ) resulted in higher C. albicans surface β-glucan exposure and msb2Δ/Δ showed attenuated virulence in a murine model of oral candidiasis. Thus, Sap-mediated proteolytic cleavage of Msb2 is required for activation of the Cek1 MAPK pathway in response to environmental cues including those that induce germination. Inhibition of Msb2 processing at the level of Saps may provide a means of attenuating MAPK signaling and reducing C. albicans virulence.

Topics: Animals; Aspartic Acid Proteases; beta-Glucans; Biofilms; Candida albicans; Candidiasis; Cell Membrane; Culture Media; Environment; Enzyme Activation; Fungal Proteins; Hyphae; MAP Kinase Signaling System; Mice; Mitogen-Activated Protein Kinase 3; Models, Biological; Mouth Diseases; Mutation; Pepstatins; Pharyngeal Diseases; Phosphorylation; Plankton; Proteolysis

There is an increasing interest in the development of therapeutic antibodies (Ab) to improve the control of fungal pathogens, but none of these reagents is available for clinical use. We previously described a murine monoclonal antibody (mAb 2G8) targeting β-glucan, a cell wall polysaccharide common to most pathogenic fungi, which conferred significant protection against Candida albicans, Aspergillus fumigatus and Cryptococcus neoformans in animal models. Transfer of this wide-spectrum, antifungal mAb into the clinical setting would allow the control of most frequent fungal infections in many different categories of patients. To this aim, two chimeric mouse-human Ab derivatives from mAb 2G8, in the format of complete IgG or scFv-Fc, were generated, transiently expressed in Nicotiana benthamiana plants and purified from leaves with high yields (approximately 50 mg Ab/kg of plant tissues). Both recombinant Abs fully retained the β-glucan-binding specificity and the antifungal activities of the cognate murine mAb against C. albicans. In fact, they recognized preferentially β1,3-linked glucan molecules present at the fungal cell surface and directly inhibited the growth of C. albicans and its adhesion to human epithelial cells in vitro. In addition, both the IgG and the scFv-Fc promoted C. albicans killing by isolated, human polymorphonuclear neutrophils in ex vivo assays and conferred significant antifungal protection in animal models of systemic or vulvovaginal C. albicans infection. These recombinant Abs represent valuable molecules for developing novel, plant-derived immunotherapeutics against candidiasis and, possibly, other fungal diseases.

Topics: Animals; Antibodies, Fungal; Antibodies, Monoclonal; Antigens, Fungal; Aspergillus fumigatus; beta-Glucans; Candida albicans; Candidiasis; Cell Adhesion; Cell Line; Cell Wall; Cryptococcus neoformans; Female; Humans; Immunoglobulin Fc Fragments; Immunoglobulin G; Immunotherapy; Mice; Models, Animal; Mycoses; Nicotiana; Plant Leaves; Plantibodies; Rats; Recombinant Fusion Proteins; Single-Chain Antibodies

The purpose of this pilot study was to determine whether β-d-glucan (BG) was associated with Candida in the lung and risk of death in patients with suspected ventilator-associated pneumonia (VAP).. In a single-center observational study, we enrolled eligible adults within 24 hours of intensive care unit admission. Patients who developed suspected VAP were divided into 3 groups according to culture results. Serum BG levels and clinical outcomes were collected.. Fifty-seven patients were included; 26 had no growth, 19 patients grew pathogenic bacteria only, and 12 patients grew only Candida. The proportion of patients with a positive BG tended to be greater in the Candida group (66.7% vs 26.3% in bacteria group vs 50.0% in culture-negative group, P = .09). The BG-positive patients were much more likely to die by day 28 than the BG-negative patients (odds ratio, 4.2; 95% confidence limits, 1.1-15.7; P = .03). Patients with both BG positivity and Candida in their lung secretions were much more likely to die compared with patients who did not.. β-d-Glucan positivity in patients with a suspected VAP may be a marker for Candida in the lung and worse outcomes. Further validation of this postulate is warranted.

Topics: Aged; Aged, 80 and over; beta-Glucans; Biomarkers; Candida; Candidiasis; Critical Illness; Female; Hospital Mortality; Humans; Intensive Care Units; Lung; Male; Middle Aged; Ontario; Pilot Projects; Pneumonia, Ventilator-Associated; Prognosis; Prospective Studies; Risk Factors

The Candida albicans gene PGA26 encodes a small cell wall protein and is upregulated during de novo wall synthesis in protoplasts. Disruption of PGA26 caused hypersensitivity to cell wall-perturbing compounds (Calcofluor white and Congo red) and to zymolyase, which degrades the cell wall β-1,3-glucan network. However, susceptibility to caspofungin, an inhibitor of β-1,3-glucan synthesis, was decreased. In addition, pga26Δ mutants show increased susceptibility to antifungals (fluconazol, posaconazol or amphotericin B) that target the plasma membrane and have altered sensitivities to environmental (heat, osmotic and oxidative) stresses. Except for a threefold increase in β-1,6-glucan and a slightly widened outer mannoprotein layer, the cell wall composition and structure was largely unaltered. Therefore, Pga26 is important for proper cell wall integrity, but does not seem to be directly involved in the synthesis of cell wall components. Deletion of PGA26 further leads to hyperfilamentation, increased biofilm formation and reduced virulence in a mouse model of disseminated candidiasis. We propose that deletion of PGA26 may cause an imbalance in the morphological switching ability of Candida, leading to attenuated dissemination and infection.

Topics: Animals; Antifungal Agents; beta-Glucans; Biofilms; Candida albicans; Candidiasis; Caspofungin; Cell Membrane; Cell Wall; Echinocandins; Female; Fungal Proteins; Glycosylphosphatidylinositols; Humans; Hyphae; Immunologic Factors; Lipopeptides; Mice; Models, Animal; Sequence Deletion; Stress, Physiological; Virulence

Multiple sclerosis (MS) is a chronic, inflammatory disease of the central nervous system, whose causes are still unknown. We have proposed that MS, as well as some ophthalmologic diseases, are associated with fungal infection. In the present study, we closely monitored a patient with MS over a three-year period. Antibodies against different Candida spp. were detected in peripheral blood serum, although the titer of these antibodies fluctuated. The presence of fungal macromolecules, such as proteins, polysaccharides, and DNA, was also tested. In several sera samples, antigens related to C. famata were evidenced by the slot-blot test using a rabbit polyclonal antibody against these species, while high levels of β-1,3 glucan were detected with the commercial Fungitell assay. Despite the variations by sample, we concluded that all fungal macromolecules, that is, proteins, polysaccharides, and DNA, were present in blood from the MS patient which was analyzed. Several fungal species were identified using polymerase chain reaction (PCR) followed by sequencing. Antibodies against Candida spp. as well as C. famata-related antigens were also detected in cerebrospinal fluid (CSF). Our findings provide support for the notion that disseminated mycosis is present in this patient.

Topics: Adult; Antibodies, Fungal; Antigens, Fungal; beta-Glucans; Candida; Candidiasis; DNA, Fungal; Humans; Longitudinal Studies; Male; Multiple Sclerosis; Polymerase Chain Reaction

Candida albicans frequently infects medical devices by growing as a biofilm, i.e., a community of adherent organisms entrenched in an extracellular matrix. During biofilm growth, Candida spp. acquire the ability to resist high concentrations of antifungal drugs. One recently recognized biofilm resistance mechanism involves drug sequestration by matrix β-1,3 glucan. Using a candidate gene approach, we investigated potential C. albicans β-1,3-glucan regulators, based on their homology to Saccharomyces cerevisiae, including SMI1 and protein kinase C (PKC) pathway components. We identified a role for the SMI1 in biofilm matrix glucan production and development of the associated drug resistance phenotype. This pathway appears to act through transcription factor Rlmp and glucan synthase Fks1p. The phenotypes of these mutant biofilms mimicked those of the smi1Δ/smi1Δ biofilm, and overexpression of FKS1 in the smi1Δ/smi1Δ mutant restored the biofilm resistant phenotype. However, control of this pathway is distinct from that of the upstream PKC pathway because the pkc1Δ/pkc1Δ, bck1Δ/bck1Δ, mkk2Δ/mkk2Δ, and mkc1Δ/mkc1Δ biofilms retained the resistant phenotype of the parent strain. In addition, resistance to cell-perturbing agents and gene expression data do not support a significant role for the cell wall integrity pathway during the biofilm formation. Here we show that Smi1p functions in conjunction with Rlm1p and Fks1p to produce drug-sequestering biofilm β-glucan. Our work provides new insight into how the C. albicans biofilm matrix production and drug resistance pathways intersect with the planktonic cell wall integrity pathway. This novel connection helps explain how pathogens in a multicellular biofilm community are protected from anti-infective therapy.

Topics: Animals; Antifungal Agents; beta-Glucans; Biofilms; Candida albicans; Candidiasis; Catheters; Cell Wall; Drug Resistance, Fungal; Fluconazole; Fungal Proteins; Gene Expression Regulation, Fungal; Gene Knockout Techniques; Glucosyltransferases; Mice; Protein Kinase C; Rats; Virulence

We have evaluated the in vitro activity of anidulafungin (AFG) against 31 strains of Candida parapsilosis sensu stricto by using broth microdilution, disk diffusion, and minimal fungicidal concentration (MFC) determination procedures. The two first methods showed a high level of activity of the drug, while MFCs were 1 to 5 dilutions higher than their corresponding MICs. To assess if MICs were predictive of in vivo outcomes, six strains representing different AFG MICs (0.12 to 2 μg/ml) were tested in a murine model of disseminated infection treated with different doses of the drug (1, 5, or 10 mg/kg of body weight). AFG was able to prolong the survival of mice infected with all the strains tested but was able to reduce the tissue burden of those mice infected only with the strains that showed the lowest MIC (0.12 μg/ml).

Topics: Anidulafungin; Animals; Antifungal Agents; beta-Glucans; Candida; Candidiasis; Echinocandins; Kaplan-Meier Estimate; Male; Mannans; Mice; Microbial Sensitivity Tests

The plasmatic levels of 1,3-beta-d-glucan (BDG) were >523 pg/ml in 4 children, 2 low-birth-weight neonates and 2 stem cell transplant recipients, with the following invasive fungal diseases (IFD) proven apart from this BDG test: 3 cases of Candida parapsilosis candidemias and 1 case of disseminated aspergillosis. The BDG test may be useful for identification of IFD in pediatrics.

Topics: Aspergillosis; Aspergillus; beta-Glucans; Candida; Candidiasis; Child; Female; Fungemia; Humans; Immunocompromised Host; Infant, Newborn; Male; Proteoglycans

Serum (1 --> 3)-beta-D-glucan levels and clinical findings were evaluated in 229 inpatients with connective tissue diseases (CTDs) during the period between June and October 2004. The mean serum (1 --> 3)-beta-D-glucan level was 129.7 +/- 207.6 pg/mL in patients with a definitive diagnosis of fungal infections and 10.5 +/- 8.6 pg/mL in patients without fungal infections. Analysis of the diagnostic sensitivity/specificity for various (1 --> 3)-beta-D-glucan cutoff levels gave the best results for a cutoff level of 15 pg/mL, with a sensitivity of 92.3% and specificity of 81.3%. This level was therefore determined to be the optimal cutoff in patients with CTDs.

Topics: Adult; Aged; Aspergillosis; beta-Glucans; Biomarkers; Candidiasis; Connective Tissue Diseases; False Positive Reactions; Female; Humans; Male; Middle Aged; Proteoglycans; Sensitivity and Specificity

Patients taking immunosuppressive drugs, like cyclosporine A (CsA), that inhibit calcineurin are highly susceptible to disseminated fungal infections, although it is unclear how these drugs suppress resistance to these opportunistic pathogens. We show that in a mouse model of disseminated Candida albicans infection, CsA-induced susceptibility to fungal infection maps to the innate immune system. To further define the cell types targeted by CsA, we generated mice with a conditional deletion of calcineurin B (CnB) in neutrophils. These mice displayed markedly decreased resistance to infection with C. albicans, and both CnB-deficient and CsA-treated neutrophils showed a defect in the ex vivo killing of C. albicans. In response to the fungal-derived pathogen-associated molecular pattern zymosan, neutrophils lacking CnB displayed impaired up-regulation of genes (IL-10, Cox2, Egr1, and Egr2) regulated by nuclear factor of activated T cells, the best characterized CnB substrate. This activity was Myd88 independent and was reproduced by stimulation with the beta(1,3) glucan curdlan, indicating that dectin-1, rather than toll-like receptors, is the upstream activator of calcineurin. Our results suggest that disseminated fungal infections seen in CsA-treated patients are not just a general consequence of systemic suppression of adaptive immunity but are, rather, a result of the specific blockade of evolutionarily conserved innate pathways for fungal resistance.

Topics: Animals; Antifungal Agents; beta-Glucans; Calcineurin; Candida albicans; Candidiasis; Cyclosporine; Disease Susceptibility; Homeostasis; Humans; Immunity, Innate; Immunosuppressive Agents; Mice; Mycoses; Neutrophils; Polysaccharides, Bacterial; Zymosan

Preparations and in vitro antifungal activities of triazolopyridines, imidazopyridines, and a pyrazolopyridine were reported. Among those scaffolds, triazolopyridine was found to be the specific inhibitor of the synthesis of beta-1,6-glucan, an essential component of the fungal cell wall, and to show potent antifungal activities against several Candida species.

Topics: Antifungal Agents; beta-Glucans; Candida; Candidiasis; Drug Stability; Humans; Imidazoles; Microsomes, Liver; Pyrazoles; Pyridines; Saccharomyces cerevisiae; Triazoles

Surveillance cultures may be helpful in identifying patients at increased risk of developing invasive candidiasis. However, only scant information exists on the effect of Candida colonization on serum levels of diagnostic biomarkers. This prospective surveillance study determined the extent of Candida colonization among pediatric cancer patients and its possible impact on serum levels of (1-3)-β-D-glucan (BDG), Candida mannan and Candida DNA.. A total of 1075 swabs originating from oropharynx (n = 294), nostrils (n = 600), rectum (n = 28), groin (n = 50), ear (n = 54), and axilla (n = 49) of 63 pediatric cancer patients were cultured for the isolation of Candida spp. Patients yielding Candida spp. from any sites were considered as colonized. Serum samples were collected from patients at the time of first surveillance culture for detection of BDG by Fungitell kit and Candida mannan by Platelia Candida Ag. Candida DNA was detected by using panfungal primers and identification was carried out by using species-specific primers and DNA sequencing.. Seventy-five (7.6%) swab cultures from 35 (55.5%) patients yielded Candida spp. These isolates included C. albicans (n = 62), C. dubliniensis (n = 8), C. glabrata and C. tropicalis (n = 2 each) and C. krusei (n = 1). Eleven patients were colonized at three or more sites. Eight of 36 serum samples from 6 colonized patients yielded BDG values higher than the currently recommended cut-off value of ≥80 pg/ml. However, none of the serum samples yielded Candida mannan levels ≥0.5 ng/ml and PCR test for Candida DNA was also negative in all the serum samples of colonized patients. During the study period, only two colonized patients subsequently developed candidemia due to C. tropicalis. Besides positive blood cultures, C. tropicalis DNA, BDG and Candida mannan were also detected in serum samples of both the patients.. The present study demonstrates that while mucosal colonization with Candida species in pediatric cancer patients is common, it does not give rise to diagnostically significant levels of Candida mannan or Candida DNA in serum specimens. However, BDG values may be higher than the cut-off value in some pediatric patients without clinical evidence of invasive Candida infection. The study suggests the utility of Candida mannan or Candida DNA in the diagnosis of invasive candidiasis, however, the BDG levels in pediatric cancer subjects should be interpreted with caution.

Topics: Adolescent; beta-Glucans; Candida; Candidiasis; Child; Child, Preschool; DNA, Fungal; DNA, Ribosomal Spacer; Humans; Infant; Leukemia; Mannans; Polymerase Chain Reaction; Proteoglycans

Topics: beta-Glucans; Candidiasis; Fungal Proteins; Fungal Vaccines; Humans; Vaccines, Conjugate

Experience with anidulafungin against Candida krusei is limited. Immunosuppressed mice were injected with 1.3 x 10(7) to 1.5 x 10(7) CFU of C. krusei. Animals were treated with saline, 40 mg/kg fluconazole, 1 mg/kg amphotericin B, or 10 and 20 mg/kg anidulafungin for 5 days. Anidulafungin improved survival and significantly reduced the number of CFU/g in kidneys and serum beta-glucan levels.

Topics: Anidulafungin; Animals; Antifungal Agents; beta-Glucans; Candida; Candidiasis; Disease Models, Animal; Echinocandins; Kidney; Male; Mice

Invasive fungal infections are associated with high morbidity and increased mortality. This study was performed to assess the epidemiology of fungal infections and to determine (1,3)-beta-D-glucan serum concentrations in patients admitted to intensive care units (ICUs).. Overall 197 patients were admitted to nine medical and surgical intensive care units (ICUs) at a 2200-bed university hospital during a 3-month period. Retrospectively, the patients were split into three groups: group A comprised 24 patients with proven invasive fungal infections admitted for a median of 40 days. Group B comprised 58 patients who were admitted to the ICU for 30 days but without fungal infection. One hundred and fifteen post-operative patients served as controls (group C). The levels of (1,3)-beta-D-glucan were monitored in all patients twice weekly during their ICU admittance.. Average (1,3)-beta-D-glucan concentrations were significantly higher in the patients with fungal infections compared to group B and group C (median 44 vs. 22 and 12.9 pg/ml, respectively; p<0.001). For a serum (1,3)-beta-D-glucan level of 40 pg/ml, the sensitivity, the specificity, the positive predictive value, the negative predictive value, the area under the curve of the receiver operating characteristics (AUC ROC) curve, the likelihood ratio (LR)+ and LR- were 52.2, 75.9, 46.2, 80, 0.7, 2.16, and 0.63, respectively, on day 7. Patients in group A had bacterial infections significantly more often than patients in group B (p=0.003). The hospitalization before ICU admittance for group A was significantly longer than for groups B and C (median 19 (group A) vs. 6 (group B) vs. 10 (group C) days; p<0.05).. Longer hospitalization and multiple bacterial infections were found to be the main risk factors for invasive fungal infections. Long-term ICU patients have elevated (1,3)-beta-D-glucan levels, not only due to invasive fungal infections, but also due to the serious underlying diseases and conditions, inter-current complications, and intensive care measures. Yet, persistently high serum levels of (1,3)-beta-D-glucan in ICU patients may be indicative of invasive fungal infections and warrant additional diagnostic efforts.

Topics: Aspergillosis; Aspergillus; beta-Glucans; Candida; Candidiasis; Female; Humans; Incidence; Intensive Care Units; Length of Stay; Male; Mycoses; Predictive Value of Tests; Proteoglycans

Although clinical experience in neonates with candidiasis exists for amphotericin B and fluconazole, these standard treatments are often hindered by drug-associated toxicity or development of resistant strains. The aim of the present study was therefore to investigate the efficacy and tolerability of a new antifungal agent, micafungin (MCFG), for treating Candida infections in premature infants.. This was a retrospective cohort study. Premature infants diagnosed with Candida infections from October 2003 to July 2004 were brought to the neonatal intensive care unit at the Center of Perinatal Medicine, Nara Medical University Hospital. Four newborns were given 0.5-1.0 mg/kg per day micafungin.. Four premature infants (mean +/- SD gestational age, 24.1 +/- 0.9 weeks; mean +/- SD birthweight, 579.3 +/- 80.5 g) experienced complications from Candida infection; two cases of the fungal infection were caused by Candida glabrata and two cases were caused by Candida albicans. MCFG was administered at 0.5 or 1.0 mg/kg per day (mean dosage days, 9.8 +/- 3.1 days) and it decreased beta-D-glucan levels while improving clinical symptoms in all cases. Additionally, there were no apparent side-effects.. MCFG is both effective and tolerable for use in premature infants suffering from Candida infections.

Topics: Antifungal Agents; beta-Glucans; Candidiasis; Echinocandins; Female; Humans; Infant, Extremely Low Birth Weight; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Lipopeptides; Male; Micafungin; Retrospective Studies; Treatment Outcome

The objective of this prospective study was to determine if Candida albicans is present in the milk of women suffering from symptoms of severe nipple and deep breast pain.. The symptomatic group included women who reported sore, inflamed, or traumatized nipples or intense stabbing or burning pain. The control group included breastfeeding women without symptoms. The skin of the nipple and areola were washed with detergent and thoroughly rinsed. Milk samples were analyzed for (1 --> 3)-beta-D-glucan and grown on Candida growth medium.. There was no significant difference in (1 --> 3)-beta-D-glucan levels between the control and symptomatic group. No Candida species were culturable either before or after the addition of iron to stimulate growth, with the exception of one patient. The addition of pure C. albicans to milk samples suggested that milk does not inhibit Candida growth.. These data suggest that C. albicans is not present in milk ducts and may not be associated with this syndrome.

Topics: Adult; beta-Glucans; Breast Feeding; Candida albicans; Candidiasis; Case-Control Studies; Female; Humans; Mastitis; Milk, Human; Nipples; Pain; Prospective Studies

Beta-1,6-glucan is a fungus-specific cell wall component that is essential for the retention of many cell wall proteins. We recently reported the discovery of a small molecule inhibitor of beta-1,6-glucan biosynthesis in yeasts. In the course of our study of its derivatives, we found a unique feature in their antifungal profile. D21-6076, one of these compounds, exhibited potent in vitro and in vivo antifungal activities against Candida glabrata. Interestingly, although it only weakly reduced the growth of Candida albicans in conventional media, it significantly prolonged the survival of mice infected by the pathogen. Biochemical evaluation of D21-6076 indicated that it inhibited beta-1,6-glucan synthesis of C. albicans, leading the cell wall proteins, which play a critical role in its virulence, to be released from the cell. Correspondingly, adhesion of C. albicans cells to mammalian cells and their hyphal elongation were strongly reduced by the drug treatment. The results of the experiment using an in vitro model of vaginal candidiasis showed that D21-6076 strongly inhibited the invasion process of C. albicans without a significant reduction in its growth in the medium. These evidences suggested that D21-6076 probably exhibited in vivo efficacy against C. albicans by inhibiting its invasion process.

Topics: Animals; Antifungal Agents; beta-Glucans; Candida albicans; Candidiasis; Female; Mice; Microbial Sensitivity Tests; Microscopy, Electron, Transmission; Microscopy, Fluorescence; Molecular Structure; Virus Internalization

Invasive Candida infections are associated with a significant morbidity and mortality. Detection of circulating biomarkers has been shown to precede conventional diagnostic methods, which is important in improving outcome. We investigated the performance of multiple biomarkers using Candida antigen and anti-Candida antibody detection systems of Platelia and Serion and beta-d-glucan detection in serial serum samples from patients, treated for leukemia, with invasive candidiasis. The performance of single assays and combined detection appeared different for patients with 1 or more episodes of neutropenia and is therefore related to the phase of therapy for the underlying leukemia of the patient. These new insights may help to optimize the diagnostic strategies for the diagnosis of invasive candidiasis.

Topics: Adolescent; Adult; Aged; Antibodies, Fungal; Antigens, Fungal; beta-Glucans; Biomarkers; Candida; Candidiasis; Child; Child, Preschool; Female; Humans; Immunosuppressive Agents; Male; Middle Aged; Myeloablative Agonists; Young Adult

C. albicans triggers recurrent infections of the alimentary tract mucosa that result from biofilm growth. Although the ability of C. albicans to form a biofilm on abiotic surfaces has been well documented in recent years, no information exists on biofilms that form directly on mucosal surfaces. The objectives of this study were to characterize the structure and composition of Candida biofilms forming on the oral mucosa. We found that oral Candida biofilms consist of yeast, hyphae, and commensal bacteria, with keratin dispersed in the intercellular spaces. Neutrophils migrate through the oral mucosa and form nests within the biofilm mass. The cell wall polysaccharide beta-glucan is exposed during mucosal biofilm growth and is more uniformly present on the surface of biofilm organisms invading the oral mucosa. We conclude that C. albicans forms complex mucosal biofilms consisting of both commensal bacterial flora and host components. These discoveries are important since they can prompt a shift of focus for current research in investigating the role of Candida-bacterial interactions in the pathogenesis of mucosal infections as well as the role of beta-glucan mediated signaling in the host response.

Topics: beta-Glucans; Biofilms; Candida albicans; Candidiasis; Cell Movement; Cell Wall; Humans; Keratins; Microscopy, Confocal; Mouth Mucosa; Mucous Membrane; Neutrophils; Polysaccharides; Signal Transduction

Mycoses, candidiasis in particular, are relatively common opportunistic infections still characterized by an unacceptable high mortality rate. Furthermore, they are often complicated by resistance or refractoriness to the existing antimicrobial agents. In recent years new effective therapeutic and large-scale preventative strategies have been proposed by exploiting the identification of fungal beta-glucans as target of antifungal agents such as echinocandins, yeast killer toxins and protective antibodies. Anti-beta-glucan antibodies are detectable in animal and human sera. When elicited by glucan-based vaccines they can exert a fungicidal protective activity. Beta-glucan cell wall killer toxin receptors can elicit fungicidal protective antibodies following natural and experimental infections. When used as an immunogen a killer toxin-neutralizing monoclonal antibody (beta-glucan-like) is able to elicit a significant anticandidal protection mediated by anti-idiotypic anti-beta-glucan-like candidacidal antibodies. Polyclonal, monoclonal and recombinant anti-beta-glucan-like antibodies and peptide mimotopes are able to exert an in vitro and/or in vivo microbicidal activity against eukaryotic and prokaryotic killer toxin receptor-bearing pathogenic microorganisms. Implications and perspectives for transphyletic anti-infectious control strategies, as immunoprevention and immunotherapy, are discussed.

Topics: Antibodies, Anti-Idiotypic; Antibodies, Fungal; beta-Glucans; Candida; Candidiasis; Fungal Vaccines; Humans; Immunity

Topics: Antifungal Agents; Antigens, Fungal; Aspergillosis; beta-Glucans; Biomarkers; Candidiasis; Humans; Neutropenia; Opportunistic Infections; Proteoglycans; Sensitivity and Specificity

The treatment, diagnosis and therapeutic monitoring of hematogenous Candida meningoencephalitis (HCME) are not well understood. We therefore studied the expression of (1-->3)-beta-D-glucan (beta-glucan) in cerebrospinal fluid (CSF) and plasma in a nonneutropenic rabbit model of experimental HCME treated with micafungin and amphotericin B. Groups studied consisted of micafungin (0.5 to 32 mg/kg) and amphotericin B (1 mg/kg) treatment groups and the untreated controls (UC). Despite well-established infection in the cerebrum, cerebellum, choroid, vitreous humor (10(2) to 10(3) CFU/ml), spinal cord, and meninges (10 to 10(2) CFU/g), only 8.1% of UC CSF cultures were positive. By comparison, all 25 UC CSF samples tested for beta-glucan were positive (755 to 7,750 pg/ml) (P < 0.001). The therapeutic response in CNS tissue was site dependent, with significant decreases of the fungal burden in the cerebrum and cerebellum starting at 8 mg/kg, in the meninges at 2 mg/kg, and in the vitreous humor at 4 mg/kg. A dosage of 24 mg/kg was required to achieve a significant effect in the spinal cord and choroid. Clearance of Candida albicans from blood cultures was not predictive of eradication of organisms from the CNS; conversely, beta-glucan levels in CSF were predictive of the therapeutic response. A significant decrease of beta-glucan concentrations in CSF, in comparison to that for UC, started at 0.5 mg/kg (P < 0.001). Levels of plasma beta-glucan were lower than levels in simultaneously obtained CSF (P < 0.05). CSF beta-glucan levels correlated in a dose-dependent pattern with therapeutic responses and with Candida infection in cerebral tissue (r = 0.842). Micafungin demonstrated dose-dependent and site-dependent activity against HCME. CSF beta-glucan may be a useful biomarker for detection and monitoring of therapeutic response in HCME.

Topics: Amphotericin B; Animals; Antifungal Agents; beta-Glucans; Biomarkers; Candidiasis; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Monitoring; Echinocandins; Female; Lipopeptides; Meningitis, Fungal; Meningoencephalitis; Micafungin; Rabbits

Candida albicans, a clinically important dimorphic fungal pathogen that can evade immune attack by masking its cell wall beta-glucan from immune recognition, mutes protective host responses mediated by the Dectin-1 beta-glucan receptor on innate immune cells. Although the ability of C. albicans to switch between a yeast- or hyphal-form is a key virulence determinant, the role of each morphotype in beta-glucan masking during infection and treatment has not been addressed. Here, we show that during infection of mice, the C. albicans beta-glucan is masked initially but becomes exposed later in several organs. At all measured stages of infection, there is no difference in beta-glucan exposure between yeast-form and hyphal cells. We have previously shown that sub-inhibitory doses of the anti-fungal drug caspofungin can expose beta-glucan in vitro, suggesting that the drug may enhance immune activity during therapy. This report shows that caspofungin also mediates beta-glucan unmasking in vivo. Surprisingly, caspofungin preferentially unmasks filamentous cells, as opposed to yeast form cells, both in vivo and in vitro. The fungicidal activity of caspofungin in vitro is also filament-biased, as corroborated using yeast-locked and hyphal-locked mutants. The uncloaking of filaments is not a general effect of anti-fungal drugs, as another anti-fungal agent does not have this effect. These results highlight the advantage of studying host-pathogen interaction in vivo and suggest new avenues for drug development.

Topics: Animals; Antifungal Agents; beta-Glucans; Candida albicans; Candidiasis; Caspofungin; Cell Wall; Disease Models, Animal; Echinocandins; Epitopes; Female; Fluconazole; Host-Pathogen Interactions; Hyphae; Lectins, C-Type; Lipopeptides; Membrane Proteins; Mice; Mice, Inbred BALB C; Microscopy, Fluorescence; Mutation; Nerve Tissue Proteins; Receptors, Immunologic

The cell walls of all medically important fungi contain a unique polyglucose compound, beta(1-3) glucan. In the present study, murine monoclonal antibodies were produced against linear and beta(1-6) branched beta(1-3) glucans, and their specificities were characterized for reactivity to other beta glucans, fungal cell wall fragments, and fungal cells. Their reactivity was also compared with that of rabbit polyclonal antibodies raised against the same immunogens. Two mouse monoclonal antibodies (AG and BG) recognized immunoreactive epitopes in beta(1-3)(1-6) glucan by ELISA. In an inhibition assay of the anti-beta(1-3)(1-6) activity of the monoclonals, the homologous antigen effectively inhibited the activity as expected, while beta(1-3) also inhibited the assay but to a much lesser extent. No inhibition was obtained by beta(1-3)(1-4) or beta(1-6), while a cell wall extract of Candida albicans (PPM) effectively inhibited both monoclonals. Cell wall fragments of C. albicans (CaCW) and Cryptococcus neoformans (CnCW) inhibited the anti-beta(1-3)(1-6) activity of AG, while BG was much less or not inhibited at all. Immunofluorescence confirmed the unique antibody specificity of AG by its recognition of a beta(1-3)(1-6)-associated epitope on the cell surfaces of C. albicans,C. krusei, C. glabrata, and nonencapsulated C. neoformans. The epitope for the AG antibody is suggested to be present in the branching point of beta(1-3)(1-6), or in the randomly coiled beta(1-3) polyglucan due to the presence of branches. Thus, monoclonal antibodies to beta(1-3)(1-6) glucans may have potential as tools in the laboratory diagnosis of invasive yeast infections.

Topics: Animals; Antibodies, Fungal; Antibodies, Monoclonal; Antibody Specificity; Antigens, Fungal; beta-Glucans; Candida albicans; Candidiasis; Cell Wall; Cross Reactions; Cryptococcosis; Cryptococcus neoformans; Enzyme-Linked Immunosorbent Assay; Epitopes; Female; Fluorescent Antibody Technique; Immune Sera; Mice; Mice, Inbred BALB C; Rabbits

Diagnosis of invasive fungal infection (IFI) remains a challenge. A retrospective study was performed on 279 patients at three French university hospitals to evaluate the performance of the (1-->3)-beta-D-glucan assay (BG assay; Fungitell; Associates of Cape Cod, Inc.) for the diagnosis of IFI. The results of one serum per subject were analyzed for 117 patients who had probable or proven IFI according to the European Organization for Research and Treatment of Cancer criteria (70 invasive pulmonary aspergilloses [IPA], 27 fungal bloodstream infections, and 20 Pneumocystis jiroveci pneumonias), 40 blood donors, and 122 patients who were hospitalized in hematology wards or intensive care units and were at risk for IFI but in whom IFI had not been diagnosed. For the overall IFI diagnosis, the BG assay had 77.8% sensitivity and specificities of 92.5 and 70.5% for blood donors and patients at risk, respectively. The assay was positive in 48 patients with IPA (68%), in 23 with bloodstream infections (85.2%), and in all who had P. jiroveci pneumonias (100%), and the false-positive rate varied depending on the controls used. It allowed a higher rate of detection among IPA patients compared to the galactomannan enzyme-linked immunosorbent assay (ELISA) (48 versus 39 patients, respectively) and among candidemia patients compared to the mannan ELISA (20 versus 11 patients, respectively). This assay therefore appears to be useful in the diagnosis of IFI, particularly for serum analysis of pneumocystosis pneumonia patients, but further studies are needed to evaluate false-positive rates and its future role in IFI diagnosis.

Topics: Aspergillosis; beta-Glucans; Blood Donors; Candidiasis; False Positive Reactions; France; Fungemia; Hospitals, University; Humans; Lung Diseases, Fungal; Mycoses; Pneumonia, Pneumocystis; Proteoglycans; Reagent Kits, Diagnostic; Sensitivity and Specificity

Topics: Antifungal Agents; Antigens, Fungal; Aspergillosis; beta-Glucans; Candidiasis; Chemoprevention; Humans; Leukemia; Proteoglycans; Triazoles

Invasive fungal infections (IFIs) are life-threatening complications in neutropenic patients with hematological malignancies. Because early diagnosis of IFI is difficult, new noninvasive, culture-independent diagnostic tools are needed to improve clinical management. Recent studies have reported that detection of 1,3-beta-D-glucan (BG) antigenemia may be useful for diagnosis of IFI. The aim of the present prospective study was to evaluate the usefulness of monitoring BG in patients undergoing chemotherapy for acute leukemia.. BG antigenemia was measured by a colorimetric assay twice weekly in the absence of fever and daily in the presence of fever. IFIs were classified according to the criteria of the European Organization for Research and Treatment of Cancer/Mycoses Study Group.. During 190 consecutive neutropenic episodes (median duration, 22 days; range, 7-113 days) in 95 patients, 30 proven or probable IFIs (13 aspergillosis, 15 candidiasis, and 2 mixed IFIs) were diagnosed. Sensitivity, specificity, positive predictive value, negative predictive value, and efficiency of 2 consecutive BG values > or =7 pg/mL for diagnosis of proven or probable IFI was 0.63 (95% confidence interval, 0.44-0.79), 0.96 (95% confidence interval, 0.89-0.98), 0.79 (95% confidence interval, 0.57-0.92), 0.91 (95% confidence interval, 0.84-0.95), and 0.89, respectively. The time interval between onset of fever as first sign of IFI and BG antigenemia was significantly shorter than the time to diagnosis of IFI by clinical, microbiological, radiological, and/or histopathological criteria (P < .001). BG values >50 pg/mL were observed in only 2 patients, both of whom experienced failure of antifungal therapy.. Monitoring of BG antigenemia is a useful noninvasive method for early diagnosis of IFI in patients with acute leukemia.

Topics: Adult; Aged; Antigens, Fungal; Aspergillosis; beta-Glucans; Candidiasis; Female; Fungemia; Humans; Leukemia, Myeloid, Acute; Male; Middle Aged; Mycoses; Neutropenia; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Predictive Value of Tests; Proteoglycans; Sensitivity and Specificity

Beta-glucan is one of the most abundant polysaccharides in fungal pathogens, yet its importance in antifungal immunity is unclear. Here we show that deficiency of dectin-1, the myeloid receptor for beta-glucan, rendered mice susceptible to infection with Candida albicans. Dectin-1-deficient leukocytes demonstrated significantly impaired responses to fungi even in the presence of opsonins. Impaired leukocyte responses were manifested in vivo by reduced inflammatory cell recruitment after fungal infection, resulting in substantially increased fungal burdens and enhanced fungal dissemination. Our results establish a fundamental function for beta-glucan recognition by dectin-1 in antifungal immunity and demonstrate a signaling non-Toll-like pattern-recognition receptor required for the induction of protective immune responses.

Topics: Animals; beta-Glucans; Candida; Candidiasis; Female; Genetic Predisposition to Disease; Lectins, C-Type; Leukocytes; Membrane Proteins; Mice; Mice, Knockout; Nerve Tissue Proteins

Biofilms are microbial communities that are associated with solid surfaces such as intravascular catheters. Candida species are a major cause of medical device-associated infections. Twenty percent to 70% of all candidemias are associated with this biofilm process. Diagnosis and effective treatment of Candida device-associated infections requires removal of the involved device. The ability to identify a biofilm device infection before catheter removal may obviate removal of a substantial number of devices. Prior studies in our laboratory identified cell wall changes (specifically, increased beta -1,3 glucan) associated with biofilm, compared with planktonic C. albicans. Both in vitro and in vivo (catheter) biofilm models were used to determine whether biofilm cells secreted more beta -1,3 glucan and whether these differences could be used to discern the presence of a Candida biofilm infection with 3 species (C. albicans, C. glabrata, and C. parapsilosis). A limulus lysate assay was used to quantify beta -1,3 glucan in supernatants from planktonic or biofilm cultures and in the serum of rats with an intravascular catheter biofilm infection or disseminated candidiasis. beta -1,3 glucan was detected from both in vitro and in vivo models from each condition. However, the concentrations of beta -1,3 glucan from the biofilm conditions were 4-10-fold greater in vitro (P<.001) and were 10-fold greater in vivo (P<.001), despite equal or fewer numbers of cells in the biofilm conditions. These results suggest the secreted polysaccharide beta -1,3 glucan may serve as a useful tool for the diagnosis of Candida biofilm and device-associated infections.

Topics: Animals; beta-Glucans; Biofilms; Candida; Candida albicans; Candida glabrata; Candidiasis; Catheterization, Central Venous; Disease Models, Animal; Humans; Limulus Test; Microscopy, Confocal; Rats

1,3-Beta-D-Glucan serum levels have demonstrated good diagnostic sensitivity and specificity for the diagnosis of candidiasis in adult patients, but normal levels for children have not been established. We found higher 1,3-beta-D-glucan levels in children than those previously reported in adults.

Topics: Adolescent; Age Factors; beta-Glucans; Biomarkers; Candidiasis; Child; Child, Preschool; Female; Humans; Infant; Male; Microbiological Techniques; Sensitivity and Specificity

The functional consequences of treating human monocytes with purified and chemically characterized Candida albicans beta-glucan -- a major microbial pathogen associated molecular pattern -- on their differentiation into dendritic cells (DC) were investigated. We show here that beta-glucan-treated monocytes differentiated into mature DC (Glu-MoDC) with altered phenotype and functional behavior, similarly to DC derived from C. albicans germ-tubes-infected monocytes (Gt-MoDC). They failed to express CD1a and to up-regulate CD80 and DR molecules. Moreover, they produced IL-10 but not IL-12 and primed naive T cells without inducing their functional polarization into effector cells. Since C. albicans beta-glucan is a mixture of both beta-(1,3) and beta-(1,6) glucan, we investigated their relative contribution by the use of non-Candida beta-glucan structural analogs. We found that high molecular weight (MW) glucans beta-(1,6) pustulan and beta-(1,3) curdlan totally mimicked the effect of C. albicans beta-glucan, while the low MW beta-(1,3) glucan laminarin did not have any effect. Because beta-glucan is a common constituent of all fungi and is abundantly released in vivo during systemic fungal infection, this novel effect of beta-glucan has potential implications for host-parasite relationship in candidiasis and other mycoses. In particular, our data suggest that beta-glucan could bias noninfected, bystander monocytes, thus aggravating the general immunodeficiency, predisposing to systemic fungal infection.

Topics: Antigen Presentation; beta-Glucans; Candida albicans; Candidiasis; Cell Differentiation; Cell Proliferation; Cell Wall; Cells, Cultured; Cytokines; Dendritic Cells; Humans; Monocytes; Phenotype; T-Lymphocytes

For the rapid diagnosis of systemic Candida infection, we compared the performance of an established seminested polymerase chain reaction (snPCR), serological tests for (1 --> 3)-beta-D-glucan assay and Candida mannan antigen assay, and blood culture in our murine model for Candida albicans translocation. In this mouse model, C. albicans disseminated to the liver from the intestine after day 6.5; the snPCR and blood culture results became positive from days 8 to 8.5 in about 60% of infected mice with culture-proven translocation, and in 100% on day 9. Both (1 --> 3)-beta-D-glucan and Candida mannan antigen were elevated in the serum as early as day 6.5 of infection, though they did not identify Candida species. Because the established snPCR can differentiate four clinically important Candida species and conventional microbiological methods require at least 48 h to identify Candida species in blood samples, the snPCR assay is advantageous for rapidly identifying Candida species in the blood. Therefore, the combination of the serological assays and the snPCR seems to be valuable for the early diagnosis of systemic C. albicans infection.

Topics: Animals; Bacterial Translocation; beta-Glucans; Blood; Candida albicans; Candidiasis; Disease Models, Animal; DNA, Bacterial; Feces; Fungemia; Liver; Mannans; Mice; Polymerase Chain Reaction; Proteoglycans; Sensitivity and Specificity; Serologic Tests

Candidemia is a major infectious complication of seriously immunocompromised patients. In the absence of specific signs and symptoms, there is a need to evolve an appropriate diagnostic approach. A number of methods based on the detection of Candida mannan, nucleic acid and (1,3)-beta- D- glucan (BDG) have been used with varying specificities and sensitivities. In this retrospective study, attention has been focused to evaluate the usefulness of two or more disease markers in the diagnosis of candidemia.. Diagnostic usefulness of Platelia Candida Ag for the detection of mannan, Platelia Candida Ab for the detection of anti-mannan antibodies, Fungitell for the detection of BDG, and of a semi-nested PCR (snPCR) for the detection Candida species-specific DNA have been retrospectively evaluated using 32 sera from 27 patients with culture-proven candidemia, 51 sera from 39 patients with clinically suspected candidemia, sera of 10 women with C. albicans vaginitis, and sera of 16 healthy controls.. Using cut-off values recommended by the manufacturers, the sensitivity of the assays for candidemia patients were as follows: Candida snPCR 88%, BDG 47%, mannan 41%, anti-mannan antibodies 47%, respectively. snPCR detected 5 patients who had candidemia due to more than one Candida species. The sensitivities of the combined tests were as follows: Candida mannan and anti-mannan antibodies 75%, and Candida mannan and BDG 56%. Addition of snPCR data improved the sensitivity further to 88%, thus adding 10 sera that were negative by BDG and/or mannan. In clinically suspected, blood culture negative patients; the positivities of the tests were as follows: Candida DNA was positive in 53%, BDG in 29%, mannan in 16%, and anti-mannan antibodies in 29%. The combined detection of mannan and BDG, and mannan, BDG and Candida DNA enhanced the positivity to 36% and 54%, respectively. None of the sera from Candida vaginitis patients and healthy subjects were positive for Candida DNA and mannan.. The observations made in this study reinforce the diagnostic value of snPCR in the sensitive and specific diagnosis of candidemia and detection of more than one Candida species in a given patient. Additionally, in the absence of a positive blood culture, snPCR detected Candida DNA in sera of more than half of the clinically suspected patients. While detection of BDG, mannan and anti-mannan antibodies singly or in combination could help enhancing sensitivity and eliminating false positive tests, a more extensive evaluation of these assays in sequentially collected serum samples is required to assess their value in the early diagnosis of candidemia.

Topics: Antibodies, Fungal; Antibody Specificity; Antigens, Fungal; beta-Glucans; Candida; Candidiasis; DNA, Fungal; Fungemia; Immunoassay; Immunoenzyme Techniques; Mannans; Polymerase Chain Reaction; Proteoglycans; Reagent Kits, Diagnostic; Retrospective Studies; Sensitivity and Specificity

Most invasive fungal infections such as candidemia are frequent in patients with hematologic malignancies. We measured cytokines/chemokines (IL-6, IL-8, monocytic chemoattractant protein 1, RANTES and epithelial neutrophil-activating peptide 78), soluble molecules (sFas, sE-selectin and soluble vascular cell adhesion molecule 1) and platelet activation markers (soluble CD40 ligand, sP-selectin and platelet-derived microparticles) in patients with hematologic malignancies under prophylactic treatment with an antifungal drug (fosfluconazole). We classified patients into 2 groups by the level of beta-D-glucan. The level of C-reactive protein was higher in the high beta-D-glucan group (>5 pg/ml) than in the low beta-D-glucan group. However, there were no differences in the levels of other parameters (peripheral blood cells, glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, lactate dehydrogenase, blood urea nitrogen and creatinine). Patients in the high beta-D-glucan group exhibited a significant elevation of several chemokines, soluble molecules and platelet activation markers compared with those in the low beta-D-glucan group, but the levels of IL-8, monocytic chemoattractant protein 1 and sFas did not differ significantly. The levels of C-reactive protein and IL-6 increased significantly after 1 or 2 weeks on fosfluconazole in both groups. In contrast, the high beta-D-glucan group exhibited a significant decrease in chemokines, soluble markers and platelet-derived microparticles compared with the low beta-D-glucan group after treatment with fosfluconazole, although the patients in the low beta-D-glucan group exhibited no significant changes. Furthermore, the levels of RANTES, epithelial neutrophil-activating peptide 78, soluble vascular cell adhesion molecule 1 and sE-selectin correlated positively with platelet-derived microparticles in the high beta-D-glucan group. These findings suggest that fungal infection may modulate the vascular events in which some platelet-related chemokines are involved.

Topics: Adult; Aged; Aged, 80 and over; Antifungal Agents; Antineoplastic Combined Chemotherapy Protocols; beta-Glucans; Biomarkers; Candidiasis; Cell Adhesion Molecules; Chemokines; Female; Fluconazole; Fungemia; Hematologic Neoplasms; Humans; Male; Middle Aged; Neutropenia; Organophosphates; Platelet Activation; Prodrugs

Topics: beta-Glucans; Biological Assay; Candidiasis; Humans; Mycoses

We have recently detected an anti-beta-glucan antibody in normal human and normal mouse sera. The anti-beta-glucan antibody showed reactivity to pathogenic fungal Aspergillus and Candida cell wall glucan. Anti-beta-glucan antibody could bind whole Candida cells. It also enhanced the candidacidal activity of macrophages in vitro. The anti-beta-glucan antibody titer of DBA/2 mice intravenously administered either Candida or Aspergillus solubilized cell wall beta-glucan decreased remarkably dependent on dose. Moreover, in deep mycosis patients, the anti-beta-glucan antibody titer decreased, and this change correlated with clinical symptoms and other parameters such as C-reactive protein. It was suggested that the anti-beta-glucan antibody formed an antigen-antibody complex and participated in the immune response as a molecule recognizing pathogenic fungi.

Topics: Animals; Antibodies, Fungal; Antibody Specificity; Antigen-Antibody Complex; Antigens, Fungal; Aspergillosis; Aspergillus; beta-Glucans; Candida; Candidiasis; Cell Wall; Female; Humans; Immunity, Innate; In Vitro Techniques; Male; Mice; Mice, Inbred DBA

The Fungitell assay (Associates of Cape Cod, Inc.) is a commercial test that detects (1-3)-beta-D-glucan (BG) and is intended for diagnosis of invasive fungal infections. To evaluate the Fungitell assay, we tested serum and plasma samples from healthy blood donors and from patients with blood cultures positive for yeast or bacteria. All 36 blood donors were BG negative, and 13 of 15 candidemic patients were BG positive. Of 25 bacteremic patients, 14 (10 with gram-positive bacteremia) were BG positive. One of the latter patients with Staphylococcus aureus bacteremia also had invasive candidiasis, based on histological findings in a tissue biopsy; therefore, the BG result was a true positive. The sensitivity, specificity, and positive and negative predictive values of the Fungitell assay, by patient, for these three groups were 93.3%, 77.2%, 51.9%, and 97.8%, respectively. We also performed the Fungitell assay on sera that had been tested for Aspergillus galactomannan or Histoplasma antigen. All six Histoplasma antigen-positive patients and 31 of 32 Aspergillus galactomannan-positive patients were also BG positive. BG results for the 10 Histoplasma antigen-negative and the 32 Aspergillus galactomannan-negative patients varied, but we were unable to confirm many of the results. Between-run coefficients of variance (CVs) for the assay ranged from 3.2% to 16.8%; within-run CVs were < or =4.8%. The correlation coefficient for an interlaboratory reproducibility study was 0.9892. Concentrations of hemoglobulin, bilirubin, and triglycerides that caused 20% interference were 588, 72, and 466 mg/dl, respectively. Our results suggest that the Fungitel assay may be most useful for excluding invasive fungal infection.

Topics: Aspergillosis; Aspergillus; beta-Glucans; Candidiasis; Fungemia; Histoplasma; Histoplasmosis; Humans; Reagent Kits, Diagnostic; Reproducibility of Results

Invasive candidiasis in patients who are immunocompromised or in intensive care units (ICUs) presents both diagnostic and therapeutic problems. We previously described antibodies that were directed against Candida albicans cell wall fragments (CW), periodate-treated CW (CW(IO4)), phosphopeptidomannan (PPM), and beta(1-3) glucan. In this study, circulating fungal antigens [mannan and beta(1-3) glucan] and immunoglobulin G (IgG) subclass antibodies to these cell wall antigens (anti-CW) were analyzed in patients with systemic candidiasis. Sera were collected from 14 patients on two or three consecutive occasions, starting on the day when candidiasis was culture proven. The sera were analyzed by enzyme-linked immunosorbent assay. The control groups consisted of lactating mothers (n = 9) (group I) who had breast milk that was positive for C. albicans and also had acute inflammation of the nipples, and age-matched blood donors (n = 10) (group II). Within the first 3 weeks of Candida infection all of the patients were positive for beta(1-3) glucan by the Gluspecy test, but no patients were positive for mannan in the less-sensitive Pastorex Candida test. The controls were negative for both beta(1-3) glucan (<20 pg/ml) and mannan (<2.5 ng/ml). IgG1 anti-CW and IgG2 anti-PPM antibodies were the most discriminatory antibodies. The ratio of IgG1 anti-CW to IgG2 anti-PPM was significantly lower in nonsurviving patients than in the other patients within the first week of candidiasis (P = 0.019). The IgG2 levels of anti-CW(IO4) and antiglucan antibodies correlated strongly (r = 0.681; P < 0.0001), and the absence of these antibodies was associated with increased levels of beta(1-3) glucan. Increased levels of IgG1 anti-CW or IgG2 anti-PPM antibodies (titer of > or = 3 logs) or of a combination of the two antibodies (log sum, > or = 5) showed 92% sensitivity, 100% specificity, and positive predictive values. In conclusion, beta(1-3) glucan and the two subclass antibodies appear to be early specific markers for the laboratory diagnosis of candidiasis. Furthermore, the kinetics of beta(1-3) glucan appearance in serum may assist in evaluating the therapeutic efficacy of antifungal treatments.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Fungal; Antibody Specificity; Antigen-Antibody Complex; beta-Glucans; Candida albicans; Candidiasis; Cell Wall; Female; Glucans; Humans; Immunoglobulin G; Male; Middle Aged; Predictive Value of Tests; Sensitivity and Specificity

The Glucatell (1-->3)- beta-D-glucan (BG) detection assay (Associates of Cape Cod) was studied as a diagnostic adjunct for invasive fungal infections (IFIs). On the basis of findings from a preliminary study of 30 candidemic subjects and 30 healthy adults, a serum BG level of >or=60 pg/mL was chosen as the cutoff. Testing was performed with serial serum samples obtained from 283 subjects with acute myeloid leukemia or myelodysplastic syndrome who were receiving antifungal prophylaxis. At least 1 serum sample was positive for BG at a median of 10 days before the clinical diagnosis in 100% of subjects with a proven or probable IFI. IFIs included candidiasis, fusariosis, trichosporonosis, and aspergillosis. Absence of a positive BG finding had a 100% negative predictive value, and the specificity of the test was 90% for a single positive test result and >or=96% for >or=2 sequential positive results. The Glucatell serum BG detection assay is highly sensitive and specific as a diagnostic adjunct for IFI.

Topics: Adult; beta-Glucans; Candidiasis; Fungemia; Humans; Leukemia, Myeloid, Acute; Limulus Test; Mycoses; Myelodysplastic Syndromes; Neutropenia; Polysaccharides; Predictive Value of Tests; Proteoglycans; Reagent Kits, Diagnostic; Sensitivity and Specificity

The purpose of the study was to investigate whether examination for plasma beta-D-glucan, a cell wall constituent of fungi, is useful for selecting surgical patients with Candida colonization who would benefit from empiric antifungal therapy. We administered fluconazole to postoperative patients with Candida colonization who have risk factors for candidemia and complained of persistent fever despite prolonged antibacterial therapy. We then analyzed the clinical outcomes regarding the number of sites colonized with Candida spp. and plasma beta-D-glucan. Of the 32 patients positive for alpha-D-glucan, 15 (46.9%) responded to the empiric therapy; only 9% of those who were negative responded (p < 0.01). In the multiple logistic regression analysis, being positive for alpha-D-glucan was a significant factor predicting response, with an adjusted odds ratio of 12.9 in patients with Candida colonization [95% confidence interval (CI) 2.07-80.73) (p < 0.01). In addition, the number of sites colonized with Candida spp. was a significant factor predicting response, with an estimated exposure odds ratio of 7.57 for those who were colonized at three or more sites compared with those colonized at one site (95% CI 1.20-47.70) (p = 0.031). In patients with Candida colonization, assessment of beta-D-glucan was useful for deciding whether to start empiric therapy for suspected candidiasis in surgical patients.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antifungal Agents; Ascomycota; beta-Glucans; Candidiasis; Female; Fluconazole; Glucans; Humans; Logistic Models; Male; Middle Aged; Odds Ratio; Patient Selection; Postoperative Complications; Predictive Value of Tests; Prospective Studies; Treatment Outcome

Major problems in the management of keratomycosis stem from the difficulty of its diagnosis and limited choice of antifungal agents. In the present paper we propose a new method of detecting (1,3)-beta-D-glucan, one of the major components of fungal cell wall, in tears from an animal model of keratomycosis. In addition, we investigated the efficacy of topical application of micafungin, a new antifungal agent that inhibits the activity of (1,3)-beta-D-glucan synthase in this animal model.. Candida albicans (5 x 10(5) organisms) was inoculated into the corneal stroma of 20 New Zealand White rabbits. The animals were randomly assigned to two groups and treated with subconjunctival injection of 0.5 mL of saline or 0.1% micafungin every day for 3 weeks. The clinical course of keratomycosis in both groups was compared. Before and 3 weeks after the injection of saline or micafungin, 5 microL of tears in each eye were collected by capillary tube. The concentration of (1,3)-beta-D-glucan was quantitatively measured by modified Limulus test.. The concentration of (1,3)-beta-D-glucan was significantly higher in keratomycosis model animals than in controls (mean +/- SD, 17.4 +/- 9.4 pg/mL and 2.8 +/- 1.8 pg/mL, respectively) at 21 days after treatment. Subconjunctival injection of micafungin had no significant effect on ocular lesions of keratomycosis until 9 days, after which ocular lesions significantly improved. Subconjunctival application of micafungin decreased the concentration of (1,3)-beta-D-glucan in tears to 4.9 +/- 3.0 pg/mL at 21 days after treatment.. Increased levels of (1,3)-beta-D-glucan in tears were detected in this model of keratomycosis. Measuring the concentration of (1,3)-beta-D-glucan in tears may be a reliable noninvasive method for the diagnosis of keratomycosis. Topical application of micafungin was effective in the treatment of keratomycosis.

Topics: Animals; beta-Glucans; Candidiasis; Corneal Diseases; Echinocandins; Eye Infections, Fungal; Glucosyltransferases; Limulus Test; Lipopeptides; Lipoproteins; Male; Micafungin; Peptides, Cyclic; Rabbits; Tears

In order to assess the performance of different methods for the detection of fungal antigens, data of five Austrian hospitals were evaluated. The enzyme immunoassay (EIA) Platelia Aspergillus Antigen (Bio-Rad, USA) was used for the diagnosis of invasive aspergillosis and compared with clinical data. It could be shown that it is more effective to investigate at least two sequential sera than only one sole serum. For several high-risk patients diagnosis could be improved or confirmed by investigating other body fluids such as cerebrospinal fluid or bronchoalveolar lavage fluid in addition to sera. For invasive Candida infections several diagnostic kits detecting antigens are commercially available. The performance of the EIA Platelia Candida Antigen (Bio-Rad, USA), the latexagglutination test Cand-Tec (Ramco, USA) and the detection of (1-3)-Beta-D-Glucan using the test kit Glucatell (CAPE COD, USA) were evaluated. The detection of (1-3)-Beta-D-Glucan by means of Glucatell showed the highest sensitivity as all sera of 15 patients with invasive candidosis showed positive results. The other tests showed positive and negative results independently of the occurrence of an invasive infection. However, the number of tested sera is too small to decide which test is the most appropriate for establishing an early and definite diagnosis. Prospective studies in combination with clinical data are still needed for definite evaluation.

Topics: Antigens, Fungal; Aspergillosis; Aspergillus; Austria; beta-Glucans; Bronchoalveolar Lavage Fluid; Candida; Candidiasis; Humans; Immunoenzyme Techniques; Latex Fixation Tests; Predictive Value of Tests; Proteoglycans; Sensitivity and Specificity

We evaluated the clinical usefulness of a polymerase chain reaction (PCR) assay amplifying the 18S ribosomal RNA gene of fungi for the diagnosis of deep candidiasis, compared with that of the beta-glucan test or Cand-Tec test. Thirty critically ill patients who had received prolonged care with intravenous hyperalimentation and endotracheal intubation in the intensive care unit and were suspected of having deep fungal infections were examined. Twenty-one were fungi positive in the PCR assay (70%). Among 24 samples in which the PCR assay, beta-glucan test and Cand-Tec test were performed simultaneously, 75% of the samples (18/24) were fungi positive in the PCR assay, whereas only 54% (13/24) had positive reactions in the beta-glucan test and 21% (5/24) in the Cand-Tec test. The results of the Cand-Tec test showed no relationship with those of the PCR or beta-glucan test. The lower limit of detection in the PCR assay was 4-5 CFU/ml of C. albicans in blood. No fungal organism was amplified from the serum of 20 healthy individuals. The results of the PCR assay and beta-glucan test showed a significant correlation in this study, but the PCR assay proved to be more sensitive than the beta-glucan test (p < 0.05), and to be more useful for the clinical diagnosis and monitoring of deep Candidiasis.

Topics: beta-Glucans; Candida; Candidiasis; Colony Count, Microbial; DNA Primers; DNA, Fungal; Electrophoresis, Agar Gel; Female; Fungemia; Genes, Fungal; Glucans; Humans; Male; Polymerase Chain Reaction; Reproducibility of Results; RNA, Fungal; RNA, Ribosomal, 18S; Sensitivity and Specificity

Clinical evaluation was retrospectively made of the results of serological diagnostic methods using plasma and/or sera of patients for the diagnosis of aspergillosis, candidosis, and pneumocystosis. Specimens were drawn from 8 patients with invasive aspergillosis, 3 with aspergilloma, 9 with candidosis, 4 with pneumocystosis, and 15 with no fungal infections. In invasive aspergillosis, the sensitivities of the (1-3)-beta-D-glucan measurement test using chromogenic and turbidimetric methods were 78.6% and 82.1%, with specificities of 75% and 87.5%, respectively. The sensitivity of the Pastorex Aspergillus test for invasive aspergillosis was 16.7%, with a specificity of 92.3%. In candidosis, the sensitivities of the (1-3)-bata-D-glucan test using the above two methods were 84.2% and 100%, with specificities of 75% and 87.5%, respectively. The sensitivity of the CAND-TEC test and the Pastorex Candida test for candidosis were 68.8% and 16.7%, with specificities of 57.1% and 100%, respectively. These results indicate that the (1-3)-bata-D-glucan measurement methods are more reliable in clinical application than the other antigen detection methods, but they still lack efficiency in differentiating fungal infections such as aspergillosis, candidosis and pneumocystosis. For a more exact diagnosis of systemic fungal infections, detailed studies on the clinical symptoms are considered essential.

Topics: Aspergillosis; beta-Glucans; Biomarkers; Candidiasis; Glucans; Humans; Pneumocystis Infections; Sensitivity and Specificity

Clinical evidence suggests that microangiopathy may be induced by fungal infection. The present study evaluated the toxic effect of (1-->3) beta-D glucan, a major component of fungal cell wall, on cultured transformed glomerular endothelial cells (TF-GEN). When TF-GEN were exposed to increasing concentrations of (1-->3) beta-D glucan (beta-DG; 115 to 430 pg/ml) for 1 to 3 hours, concentration- and time-dependent increases in hydroxyl radical production were demonstrated by electron paramagnetic resonance spectrometry using 5, 5-dimethyl-1-pyrrolyne-N-oxide as a spin trap agent. The amount of radicals induced by 230 or 430 pg/ml beta-DG was comparable to that induced by E. coli LPS (1 or 10 microg/ml). The beta-DG-induced free radical production was associated with a subsequent increase in LDH release from TF-GEN. When TF-GEN pretreated with U78517F (0.1 or 1.0 microM), a lipophilic antioxidant, were stimulated with LPS (1 or 10 microg/ml) or beta-DG (230 pg/ml) for 3 hours, free radical production by TF-GEN was significantly reduced in cells pretreated with the higher concentration of U78517F. Thus, fungal (1-->3) beta-D glucan induces glomerular endothelial injury by stimulating cellular free radical production. Such a mechanism may underlie microangiopathy in systemic fungal infections.

Topics: Animals; beta-Glucans; Candida albicans; Candidiasis; Cattle; Cell Wall; Chromans; Electron Spin Resonance Spectroscopy; Endothelium, Vascular; Free Radical Scavengers; Free Radicals; Glucans; Kidney Glomerulus; Piperazines; Vascular Diseases

Candida spp. is a medically important fungi which induces disseminated candidiasis and candidemia in hospitalized immunocompromised patients. The cell wall of Candida is mainly composed of two polysaccharides, mannan and beta-glucan, and at least part of beta-glucan is basically insoluble in H2O or NaOH. We became interested in when and how particulate beta-glucan changes to the soluble form. However, the fate of wall components has not been examined in detail. In this study, modification and solubilization of the cell wall beta-glucan were analyzed in vivo and in vitro. Cells of Candida, intravenously administered to mice (1 mg/mouse), were immediately deposited mainly in liver as determined by 3H-labeled cells. Beta-Glucans were detected in these mice for at least for 6 months by the beta-glucan specific assay. During this period, the insoluble cell wall beta-glucan was gradually solubilized in these organs, probably by oxidative stress of macrophages. Candida cells and particulate beta-glucans were also gradually solubilized in vitro using sodium hypochlorite solution, but part of the cell wall beta-glucan was still insoluble even after treatment with concentrated hypochlorite solution for one day at room temperature. These findings strongly suggested that the fungal cell wall beta-glucans were quite resistant to oxidative metabolism in vivo and in vitro, and thus deposited for quite long period in the host.

Topics: Animals; beta-Glucans; Candida; Candida albicans; Candidiasis; Cell Wall; Glucans; Limulus Test; Male; Mice; Mice, Inbred ICR; Oxidation-Reduction; Sodium Hydroxide; Sodium Hypochlorite

To investigate the utility of measuring blood concentrations of (1-->3)-beta-D-glucan, a component of the fungal cell wall, as an auxiliary diagnostic method for systemic candidiasis, rats were inoculated with Candida albicans and the number of C. albicans in the viscera and glucan in the blood were quantitated. The concentration of blood glucan and the number of C. albicans in the viscera were also measured both under leukopenia and with deteriorated reticuloendothelial system cell function, and when the liver and spleen had been excised. As a result, systemic candidiasis appeared in the group with leukopenia, and the number of living C. albicans increased in the kidney and liver. Together with this increase in the number of C. albicans, there was an increase in blood (1--> 3)-beta-D-glucan. Measurements of blood (1--> 3)-beta-D-glucan well reflect a proliferation of C. albicans in vivo, which would make this a useful auxiliary for the clinical diagnosis of systemic mycosis.

Topics: Animals; beta-Glucans; Candida albicans; Candidiasis; Glucans; Male; Rats; Rats, Wistar

The limulus factor G reacts with (1-->3)-beta-D-glucan, a major structural component of fungal cell walls. The Fungitec G test is a colorimetric assay that measures the concentration of (1-->3)-beta-D-glucan and is used as a serodiagnostic test for deep mycosis. Wako-WB003 is another assay for (1-->3)-beta-D-glucan that determines the change in turbidity of the gelatin reaction of limulus factor G with (1-->3)-beta-D-glucan. In five rabbits inoculated intravenously with 1 x 10(7) CFU of Candida albicans, the concentration of (1-->3)-beta-D-glucan measured by the fungitec G test increased gradually reaching a peak of 660.9 +/- 427.9 pg/ml (mean +/- SD) 4 days after inoculation, but to 42.225 +/- 41.275 ng/ml on day 6 in the Wako-WB003 test. In one rabbit challenged intravenously with 5 x 10(6) CFU of C. albicans, (1-->3)-beta-D-glucan increased to 101.5 pg/ml on day 4 on the fungitec G test, whereas the level remained below the detection limit of the Wako-WB003 test throughout the course of the disease. We also detected high concentrations of (1-->3)-beta-D-glucan in 11 patients with candidemia, 4 with suspected candidemia, 1 with invasive pulmonary aspergillosis, and 12 patients with aspergilloma. The concentration of (1-->3)-beta-D-glucan measured by the Fungitec G test was > 150, > 1006.8; 312.1, and 55.6 +/- 37.4 pg/ml (range, 20.1-138.0 pg/ml), and by the Wako-WB003 test > 153.000, > 17.70, 153.000 and 2.645 +/- 7.248 ng/ml (range, < 25.20 ng/ml) in these patients, respectively. In contrast, the concentration of (1-->3)-beta-D-glucan in 9 patients with pulmonary cryptococcosis and 6 with superficial candida colonization ranged from < 13.2 and < 15.3 pg/ml in the Fungitec G test and < 0.53 and < 0.12 ng/ml in Wako-WB003 test. There was a weak relationship between the concentration of (1-->3)-beta-D-glucan measured by the Fungitec G test and Wako-WB003 test (r = 0.521). Our results indicate that the sensitivity of the Wako-WB003 test is lower than that of the Fungitec G test.

Topics: Animals; Antigens, Fungal; beta-Glucans; Candida albicans; Candidiasis; Glucans; Humans; Limulus Test; Rabbits; Regression Analysis; Sensitivity and Specificity

The present multicentre clinical study was conducted to assess the clinical utility of a new diagnostic method for deep mycosis in which (1-->3)-beta-D-glucan, a fungal cell wall component existing in plasma, was quantitatively measured by the kinetic turbidimetric Limulus test (WB003). Plasma (1-->3)-beta-D-glucan concentrations were 0.57 +/- 0.10 microgram/l in 92 healthy subjects and 0.62 +/- 0.32 microgram/l in 26 patients with non-mycotic diseases (disease control group). In comparison with these healthy subjects and patients with non-mycotic diseases, patients with mycosis had significantly higher plasma (1-->3)-beta-D-glucan concentrations: 19.63 +/- 73.28 micrograms/l in 12 patients with candidaemia, 11.28 +/- 21.42 micrograms/l in 7 patients with urinary Candida infection, 4.84 +/- 12.71 micrograms/l in 5 patients with pulmonary candidiasis, and 12.21 +/- 31.31 micrograms/l in 4 patients with invasive pulmonary aspergillosis. On the statistical analysis of these data, a cut-off value was set at 1.0 microgram/l. Using this cut-off value, 3 patients with pulmonary cryptococcosis and 4 patients (4/6) with pulmonary aspergilloma were all negative with low plasma (1-->3-beta-D-glucan levels. The test WB003 provided equivalent or higher efficiency of diagnosis of candidiasis and aspergillosis, in comparison with commercially available antigen detection kits, demonstrating its utility as a diagnostic reagent. It may also be useful in assessing therapeutic effectiveness when used periodically after treatment.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Aspergillosis; beta-Glucans; Candidiasis; Cryptococcosis; Diagnostic Errors; Evaluation Studies as Topic; Female; Fungemia; Glucans; Humans; Kinetics; Limulus Test; Lung Diseases, Fungal; Male; Middle Aged; Mycoses; Nephelometry and Turbidimetry; Time Factors; Urinary Tract Infections

A 16-year-old male with a long history of steroid-responsive nephrotic syndrome developed fever, abdominal pain, thrombocytopenia and acute renal failure. The clinical course and renal histology were similar to, but not typical of, haemolytic uremic syndrome. Positive cultures (throat, oesophagus, stool), an elevation in serum levels of specific antibody and fungal polysaccharide (1,3) beta-D-glucan and response to the antifungal therapy indicated an association between this syndrome and infection with Candida albicans.

Topics: Acute Kidney Injury; Adolescent; beta-Glucans; Candidiasis; Glucans; Hemolytic-Uremic Syndrome; Humans; Kidney Glomerulus; Male; Nephrotic Syndrome; Renal Dialysis

(1-->3)-beta-D-glucan is a characteristic fungal cell-wall constituent. To assess the clinical usefulness of this glucan in screening for invasive fungal infection or fungal febrile episodes, we measured the plasma concentration at the time of routine blood culture in 202 febrile episodes by means of factor G, a horseshoe-crab coagulation enzyme that is extremely sensitive to this polysaccharide. With a plasma cut-off value of 20 pg/mL, 37 of 41 episodes of definite fungal infections (confirmed at necropsy or by microbiology) had positive results (sensitivity 90%). All of 59 episodes of non-fungal infections, tumour fever, or collagen diseases had concentrations below the cut-off value (specificity 100%). Of 102 episodes of fever of unknown origin, 26 had plasma glucan concentrations of more than 20 pg/mL. With those 102 cases taken as non-fungal infections, the positive predictive value of the test was estimated as 59% (37/63), the negative predictive value as 97% (135/139), and the efficiency as 85% (172/202). The positive predictive value should improve if there were a sensitive gold standard that could discriminate fungal from non-fungal infections. Causative fungi included candida, aspergillus, cryptococcus, and trichosporon. Determination of plasma (1-->3)-beta-D-glucan with factor G is a highly sensitive and specific test for invasive deep mycosis and fungal febrile episodes, and will substantially benefit immunocompromised patients.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Aspergillosis; beta-Glucans; Blood Coagulation Factors; Candidiasis; Child; Child, Preschool; Female; Fever; Fungemia; Glucans; Humans; Male; Middle Aged; Mycoses; Sensitivity and Specificity; Serine Endopeptidases

It has been difficult to diagnose the deep-seated fungal infection. Limulus test which originally has been developed to detect endotoxin in blood is also activated by (1-->3)-beta-D-glucan, the cell wall component of the fungi. Factor G in limulus lysate is activated by (1-->3)-beta-D-glucan and not by endotoxin. The quantitative assay of (1-->3)-beta-D-glucan is possible by the G-test using factor G. (1-->3)-beta-D-glucan in RPMI culture medium of Candida albicans was periodically measured using G-test and the effect of antifungal drug or neutrophil to the changes of (1-->3)-beta-D-glucan in the culture medium was studied. Increase in the level of (1-->3)-beta-D-glucan was in parallel with the growth of Candida albicans. G-test may be applied to the clinical diagnosis of fungal infection.

Topics: beta-Glucans; Candida albicans; Candidiasis; Culture Media; Glucans; Humans; Limulus Test

An indirect method to measure beta-glucan, a major structural component of yeast cell walls, is available, but has the disadvantage of requiring the combined use of two assays. Recent reports describe the fungal index, which measures the difference between the conventional limulus test, in which factors C and G react with endotoxin and beta-glucan, and a new endotoxin-specific test, in which only factor C reacts with endotoxin. The G test was developed as a direct method to measure beta-glucan, and contains only factor G reacting with beta-glucan alone. In this study, the G test was examined in sera of rabbits with experimental systemic candidiasis, and compared with the fungal index and mannan assay. The G test showed positive in all rabbits with systemic candidiasis faster and with higher titers than with the fungal index. Three rabbits with fulminant systemic candidiasis showed higher levels of reactivity with the G test and the fungal index than two rabbits with mild reactions. Mannan was positive by at least one serum in four of five rabbits by the latex agglutination test, and there was a good correlation between these assays. The G test is a good serodiagnostic method for the detection of candidiasis.

Topics: Animals; Antigens, Fungal; beta-Glucans; Candidiasis; Disease Models, Animal; Evaluation Studies as Topic; Glucans; Limulus Test; Mannans; Mycology; Rabbits; Sensitivity and Specificity

The in vivo anti-Candida activities of 1,3-beta-D-glucan synthesis inhibitors L-671,329, L-646,991 (cilofungin), L-687,901 (tetrahydroechinocandin B), and L-687,781 (a papulacandin analog) were evaluated by utilizing a murine model of disseminated candidiasis that has enhanced susceptibility to Candida albicans but increased sensitivity for discriminating antifungal efficacy. DBA/2 mice were challenged intravenously with 1 x 10(4) to 5 x 10(4) CFU of C. albicans MY1055 per mouse. Compounds were administered intraperitoneally at concentrations ranging from 1.25 to 10 mg/kg of body weight twice daily for 4 days. At 6 h and 1, 2, 3, 4, 7, and 9 days after challenge, five mice per group were sacrificed and their kidneys were homogenized and plated for enumeration of Candida organisms (CFU per gram). Progressiveness of response trends and no-statistical-significance-of-trend doses were derived to rank compound efficacy. 1,3-beta-D-Glucan synthesis 50% inhibitory concentrations were determined by using a C. albicans (MY1208) membrane glucan assay. Candida and Cryptococcus neoformans MICs and minimal fungicidal concentrations were determined by broth microdilution. L-671,329, L-646,991, L-687,901, and L-687,781 showed similar 1,3-beta-D-glucan activities, with 50% inhibitory concentrations of 0.64, 1.30, 0.85, and 0.16 micrograms/ml, respectively. Data from in vitro antifungal susceptibility studies showed that L-671,329, L-646,991, and L-687,901 had similar MICs ranging from 0.5 to 1.0 micrograms/ml, while L-687,781 showed slightly higher MICs of 1.0 to 2.0 micrograms/ml for C. albicans MY1055. Lipopeptide compounds were ineffective against C. neoformans strains. Results from in vivo experiments comparing significant trend and progressiveness in response analyses indicated that L-671,329 and L-646,991 were equipotent but slightly less active than L-687-901, while L-687,781 was ineffective at 10 mg/kg. Fungicidal activities of L-671,329, L-646,991, and L-687,901 were observed in vivo, with significant reduction in Candida CFU per gram of kidneys compared with those in sham-treated mice at doses of > or = 2.5 mg/kg evident as early as 1 day after challenge.

Topics: Animals; Anti-Bacterial Agents; Antifungal Agents; Azoles; beta-Glucans; Candida albicans; Candidiasis; Echinocandins; Glucans; Kidney; Lethal Dose 50; Mice; Mice, Inbred DBA; Microbial Sensitivity Tests; Peptides; Peptides, Cyclic; Pyrans

Factor G, the coagulation enzyme from limulus amebocytes, is activated by (1-->3)-beta-D-glucan but not by endotoxin. The endotoxin-specific limulus test, which is devoid of factor G, reacts only with endotoxin. However, the conventional limulus test which includes factors G and C, reacts with not only endotoxin but also with (1-->3)-beta-D-glucan. In this study, the culture supernatant of Candida albicans in RPMI medium activated the conventional limulus test, but not the endotoxin-specific limulus test. All five rabbits inoculated intravenously with Candida albicans (1.0 x 10(7) CFU/rabbit) showed increased levels of reactivity with the conventional limulus test, whereas no elevation in the levels of the endotoxin-specific limulus test was observed in the sera of any infected rabbits. Only one serum sample from rabbit No. 5 on day 8 showed a positive Cand-tectest. The difference in the titers of the two limulus tests was suggestive of a diagnosis of Candida infection.

Topics: Amino Acid Sequence; Animals; beta-Glucans; Candida albicans; Candidiasis; Endotoxins; Glucans; Limulus Test; Molecular Sequence Data; Polysaccharides; Rabbits

A new beta-1,3-D-glucan synthesis inhibitor, L-687,781 is produced by the cultivation of Dictyochaeta simplex ATCC 20960. L-687,781 exhibits potent in vitro antifungal activity as well as anti-Pneumocystis activity in a rat model.

Topics: Animals; Antifungal Agents; beta-Glucans; Candida; Candidiasis; Cryptococcus neoformans; Disease Models, Animal; Fermentation; Fungi; Glucans; Male; Mice; Mitosporic Fungi; Pneumonia, Pneumocystis; Pyrans; Rats; Rats, Inbred Strains

In order to correctly diagnose and treat severe postoperative infections, it may be critical to detect and differentiate between endotoxin derived from Gram-negative bacteria and/or beta-glucan derived from fungi. In addition to the chromogenic assay, the turbidimetric kinetic assay has been performed for the quantification of endotoxin in plasma using Limulus amebocyte lysate as previously reported. However, it is also known that beta-glucan triggers the coagulation of Limulus amebocyte lysate. In the present study, the differentiation of beta-glucan from endotoxin and its clinical application were studied. Endotoxin was able to be inactivated in plasma using one-tenth dilution by 10 per cent ethanol or distilled water, followed by heating at 100 degrees C for 120 min, without affecting the activity of coexisting beta-glucan. The treated sample was then subjected to the turbidimetric kinetic assay using Toxinometer ET-201. Using this method, as little as 30 pg/ml of beta-glucan in the plasma may be assayed separately, with the amount of circulating beta-glucan in the plasma of normal subjects being less than 50 pg/ml. On the other hand, in patients with a fungal infection, the amount of beta-glucan in their plasma was elevated significantly. Clinically, beta-glucanemia may often occur in severe postoperative infection even if fungi are not detected.

Topics: beta-Glucans; Candidiasis; Endotoxins; Escherichia coli Infections; Glucans; Humans; Mycoses; Pseudomonas aeruginosa; Pseudomonas Infections; Reference Values; Salmonella Infections; Surgical Wound Infection

Since beta-1,3-glucan is a common component of fungal cell wall, its detection might be useful in diagnosing invasive candidiasis. Not only endotoxin but beta-1,3-glucan activates proclotting enzyme contained in a conventional chromogenic limulus test (CCLT). Endotoxin activates this enzyme through factor C, while the beta-1,3-glucan activates through factor G. Since endotoxin specific test (EST) contains factor C, endotoxin would be quantified. By subtracting EST value from CCLT value, beta-1,3-glucan would be quantified. We named this value Fungal Index (FI), and examined if it actually reflects the candidal infection. Ninety-two patients were tested for CCLT and EST prospectively. FI increased significantly in candidal infection (p less than 0.05) but remained low in GNR infection. Moreover, FI increased proportionally to the severity of candidal infection. Elevated FI decreased when antifungal therapy was successful. Thus FI was a useful index not only in the diagnosis of invasive candidiasis but also in the evaluation of antifungal therapy.

Topics: Antifungal Agents; Bacterial Infections; beta-Glucans; Candidiasis; Chromogenic Compounds; Endotoxins; Escherichia coli; Glucans; Humans; Limulus Test; Mycology; Prospective Studies