laminaran and Candidiasis

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Polysaccharide-encapsulated fungi are the chief source of diseases in immunocompromised hosts such as those infected with human immunodeficiency virus or neutropenia patients. Currently available polysaccharide-protein conjugate vaccines are mainly T cell dependent and are usually ineffective in weakened immune systems. In this study, laminarin, a well-characterized β-1,3-glucan, was conjugated with a prokaryotically expressed recombinant fragment (amino acids [aa] 39 to 272) of calreticulin (rCRT/39-272), which exhibits extraordinarily potent immunogenicity and adjuvanticity in experimental animals. The resultant conjugate reserves the immunostimulatory effect of rCRT/39-272 on naïve murine B cells and is capable of eliciting anti-β-glucan IgG (mostly IgG1) responses in not only BALB/c mice but also athymic nude mice. Laminarin-CRT-induced mouse antibodies (Abs) are able to bind with Candida albicans and inhibit its growth in vitro. In addition, vaccination with laminarin-CRT partially protects mice from lethal C. albicans challenge. These results imply that rCRT/39-272 could be used as an ideal carrier or adjuvant for carbohydrate vaccines aimed at inducing or boosting IgG responses to fungal infections in immunodeficient hosts.

Topics: Adjuvants, Immunologic; Animals; Antibodies, Fungal; Calreticulin; Candida albicans; Candidiasis; Female; Fungal Vaccines; Glucans; Immunoglobulin G; Mice; Mice, Inbred BALB C; Mice, Nude; Polysaccharides; Recombinant Proteins; Survival Analysis; Vaccines, Conjugate; Vaccines, Synthetic

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

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

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

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 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

Peptides derived from the sequence of a single-chain, recombinant, antiidiotypic antibody (IdAb; KT-scFv) acting as a functional internal image of a microbicidal, wide-spectrum yeast killer toxin (KT) were synthesized and studied for their antimicrobial activity by using the KT-susceptible Candida albicans as model organism. A decapeptide containing the first three amino acids (SAS) of the light chain CDR1 was selected and optimized by alanine replacement of a single residue. This peptide exerted a strong candidacidal activity in vitro, with a 50% inhibitory concentration of 0.056 microM, and was therefore designated killer peptide (KP). Its activity was neutralized by laminarin, a beta1-3 glucan molecule, but not by pustulan, a beta1-6 glucan molecule. KP also competed with the binding of a KT-like monoclonal IdAb to germinating cells of the fungus. In a rat model of vaginal candidiasis, local, postchallenge administration of KP was efficacious in rapidly abating infections caused by fluconazole-susceptible or -resistant C. albicans strains. In systemic infection of BALB/c or SCID mice preinfected intravenously with a lethal fungal load, KP caused a highly significant prolongation of the median survival time, with >80% of the animals still surviving after >60 days, whereas >90% of control mice died within 3 to 5 days. KP is therefore the first engineered peptide derived from a recombinant IdAb retaining KT microbicidal activity, probably through the interaction with the beta-glucan KT receptor on target microbial cells.

Topics: Amino Acid Sequence; Animals; Antibodies, Anti-Idiotypic; Antibodies, Monoclonal; Base Sequence; Candidiasis; Candidiasis, Vulvovaginal; Female; Glucans; Immunoglobulin Fragments; Killer Factors, Yeast; Mice; Mice, Inbred BALB C; Mice, SCID; Molecular Sequence Data; Mycotoxins; Oligopeptides; Peptides; Polysaccharides; Protein Engineering; Rats; Recombinant Proteins

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

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