muramidase and Candidiasis

Lysozyme and lactoferrin have anti-candidal activity. Candida dubliniensis is associated with oral candidiasis. Candida infections are managed with nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine. Candida species undergo a brief exposure to therapeutic agents in the mouth. There is no data on the influence of limited exposure to antimycotics on the sensitivity of C. dubliniensis to lactoferrin and lysozyme. Hence, this study observed the changes in the sensitivity of C. dubliniensis to anti-candidal action of lactoferrin and lysozyme after transitory exposure to sub-lethal concentrations of antifungals.. After determination of the minimum inhibitory concentration (MIC), 20 C. dubliniensis isolates were exposed to twice the concentration of MIC of nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine for 1 h. Drugs were removed by dilution and thereafter the susceptibility of these isolates to lysozyme and lactoferrin was determined by colony-forming unit quantification assay.. Exposure of C. dubliniensis to nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine resulted in an increase in susceptibility to lysozyme by 9.45, 30.82, 30.04, 50.64, 55.60, and 50.18%, respectively (p < 0.05 to p < 0.001). Exposure of C. dubliniensis to nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine resulted in an increase in susceptibility to lactoferrin by 13.54, 16.43, 17.58, 19.60, 21.32, and 18.73, respectively (p < 0.05 to p < 0.001).. Brief exposure to nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine enhances the antifungal effect of lysozyme and lactoferrin on C. dubliniensis isolates in vitro.

Topics: Anti-Infective Agents; Antifungal Agents; Candida; Candidiasis; Humans; Kuwait; Lactoferrin; Mouth Diseases; Muramidase

Lysozymes are widely distributed immune effectors exerting muramidase activity against the peptidoglycan of the bacterial cell wall to trigger cell lysis. However, some invertebrate-type (i-type) lysozymes deficient of muramidase activity still exhibit antimicrobial activity. To date, the mechanism underlying the antimicrobial effect of muramidase-deficient i-type lysozymes remains unclear. Accordingly, this study characterized a novel i-type lysozyme, Splys-i, in the mud crab Scylla paramamosain. Splys-i shared the highest identity with the Litopenaeus vannamei i-type lysozyme (Lvlys-i2, 54% identity) at the amino acid level. Alignment analysis and 3D structure comparison show that Splys-i may be a muramidase-deficient i-type lysozyme because it lacks the two conserved catalytic residues (Glu and Asp) that are necessary for muramidase activity. Splys-i is mainly distributed in the intestine, stomach, gills, hepatopancreas, and hemocytes, and it is upregulated by Vibrio harveyi or Staphylococcus aureus challenge. Recombinant Splys-i protein (rSplys-i) can inhibit the growth of Gram-negative bacteria (V. harveyi, Vibrio alginolyticus, Vibrio parahemolyticus, and Escherichia coli), Gram-positive bacteria (S. aureus, Bacillus subtilis, and Bacillus megaterium), and the fungus Candida albicans to varying degrees. In this study, two binding assays and a bacterial agglutination assay were conducted to elucidate the potential antimicrobial mechanisms of Splys-i. Results demonstrated that rSplys-i could bind to all nine aforementioned microorganisms. It also exhibited a strong binding activity to lipopolysaccharide from E. coli and lipoteichoic acid and peptidoglycan (PGN) from S. aureus but a weak binding activity to PGN from B. subtilis and β-glucan from fungi. Moreover, rSplys-i could agglutinate these nine types of microorganisms in the presence of Ca

Topics: Agglutination; Animals; Anti-Infective Agents; Arthropod Proteins; Brachyura; Candidiasis; Carbon-Nitrogen Lyases; Cell Growth Processes; Cloning, Molecular; Immunity, Innate; Intestinal Mucosa; Lipopolysaccharides; Muramidase; Protein Binding; Proteoglycans; Sequence Alignment; Staphylococcal Infections; Staphylococcus aureus; Vibrio; Vibrio Infections

Infectious diseases are detrimental to the health and economy of the livestock industry. Observations of cattle resistant to natural infections have implied the feasibility of breeding livestock for disease resistance. Studies of pigs selected for antibody (AMIR)- and cell (CMIR)-mediated immune responses have demonstrated increased immune responsiveness suggesting enhanced protection by both type 2 and type 1 responses, respectively. Additionally, natural or artificial infections of cattle suggest that the production of particular immunoglobulin (Ig) M, IgG1 and IgG2 isotypes are important for protecting against pathogens. In fact, IgG1/IgG2 ratios are often used to establish whether type 1 (CMIR) or type 2 (AMIR) responses predominate following immunization or infection. The objectives of this study were therefore; (1) to evaluate the Ig isotype bias responses to Candida albicans and hen-egg white lysozyme (HEWL) in cows classified as high responders (HR), average responders (AR) or low responders (LR) based on AMIR or CMIR; (2) to determine if ranking based on IFN-γ (a type 1 cytokine) and DTH responses were analogous in terms of ranking; and (3) to estimate IFN-γ, Ig isotypes, and DTH correlations. Antibody responses to HEWL and DTH to C. albicans were detected such that cows were phenotypically classified as HR, AR and LR for AMIR or CMIR with significant differences (p ≤ 0.05) among classified groups. C. albicans-induced IFN-γ allowed classification of cows, some of which had the same ranking as that of DTH response. The lowest IgG1/IgG2 ratio was to the C. albicans purified antigen (candin), but no differences were observed in anti-HEWL or anti-candin IgG1/IgG2 ratios between classified groups. Anti-HEWL IgG1 and IgG2 responses at day 21 post-immunization were negatively and significantly correlated with DTH to candin at 24h. There were no significant correlations between anti-HEWL or anti-candin IgG1 or IgG2 responses with IFN-γ. Based on Ig isotype bias, IFN-γ and DTH responses, it was concluded that immunization with C. albicans can be used to classify CMIR responder cows based on DTH read-out.

Topics: Animals; Antibody Formation; Candida albicans; Candidiasis; Cattle; Female; Hypersensitivity, Delayed; Immunoglobulin G; Immunoglobulin Isotypes; Immunoglobulin M; Interferon-gamma; Lactation; Muramidase; Phenotype

The study aimed to describe the patterns and density of early tracheal colonization among intubated patients and to correlate colonization status with levels of antimicrobial peptides and inflammatory cytokines.. The was a prospective cohort study.. The study was conducted in medical and cardiovascular intensive care units of a tertiary referral hospital.. Seventy-four adult patients admitted between March 2003 and May 2006 were recruited for the study.. Tracheal aspirates were collected daily for the first 4 days of intubation using standardized, sterile technique and sent for quantitative culture and cytokines, lactoferrin and lysozyme measurements.. The mean acute physiology and chronic health evaluation (APACHE II) score in this cohort was 24 +/- 7. Proportion of subjects colonized by any microorganism increased over the first 4 days of intubation (47%, 60%, 70%, 70%, P = .08), but density of colonization for bacteria or yeast did not change significantly. No known risk factors predicted tracheal colonization on day 1 of intubation. Several patterns of colonization were observed (persistent, transient, new colonization, and clearance of initial colonization).The most common organisms cultured were Candida albicans and coagulase-negative Staphylococcus. Levels of cytokines, lactoferrin, or lysozyme did not change over time and were not correlated with tracheal colonization status. Four subjects (6%) had ventilator-associated pneumonia.. The density of tracheal colonization did not change significantly over the first 4 days of intubation in medical intensive care unit patients. There was no correlation between tracheal colonization and the levels of antimicrobial peptides or cytokines. Several different patterns of colonization may have to be considered while planning interventions to reduce airway colonization.

Topics: Adult; APACHE; Candidiasis; Case-Control Studies; Colony Count, Microbial; Cross Infection; Cytokines; Female; Humans; Inflammation; Intensive Care Units; Intubation, Intratracheal; Lactoferrin; Logistic Models; Male; Middle Aged; Multivariate Analysis; Muramidase; Pneumonia, Ventilator-Associated; Prospective Studies; Respiration, Artificial; Respiratory Mucosa; Risk Factors; Staphylococcal Infections; Statistics, Nonparametric; Suction; Time Factors; Trachea

Candida albicans, as an opportunistic pathogen, causes therapeutic problems in immunocompetent individuals and frequently it initiates severe infections in immunocompromised hosts. The application of a lysozyme digest preparation from the cell walls of Nocardia opaca (Nocardia lysozyme digest; NLD), recently classified as Rhodococcus opacus, has a protective effect in intravenous (i.v.) C. albicans infections in inbred ICR mice which have normal complement production. It also significantly reduces i.v. and intraperitoneal (i.p.) infections in DBA/2 mice which are deficient in C5 complement component. A significant decrease in C. albicans recovery from kidneys was found in NLD-treated DBA/2 animals. The preparation enhanced delayed type hypersensitivity to the yeast cells in both mouse strains. C. albicans-induced popliteal lymph node reactions were increased in ICR mice. In addition, mouse splenocytes that had been inhibited in their proliferative response to phytohaemagglutinin had this response restored after exposure to the preparation. NLD decreased the sensitivity of both mouse strains to a second challenge with the pathogen. The preparation restored the impaired host response to C. albicans infection in ICR mice treated with cobra venom and cyclophosphamide.

Topics: Animals; Candidiasis; Female; Hypersensitivity, Delayed; Immune Tolerance; Lymphocyte Activation; Mice; Mice, Inbred DBA; Mice, Inbred ICR; Muramidase; Nocardia

Lactoferrin and lysozyme (muramidase) are non-immune defence factors present in various exocrine secretions, including saliva. Previous studies have shown that both proteins, either singly or in combination, are bactericidal in nature and their combined activity is synergistic. As little is known of their interactions with Candida species, 20 oral isolates of C. krusei and 5 isolates of C. albicans were studied for their susceptibility to human apo-lactoferrin and lysozyme, either singly or in combination, using an in vitro assay system. The two species exhibited significant interspecies differences in susceptibility to lactoferrin (p < 0.05), but not for lysozyme; C. krusei being more sensitive to lactoferrin (c 1.4 times) than C. albicans. Both species revealed significant intraspecies differences in their susceptibility to lysozyme (p < 0.05), but not for lactoferrin. No synergistic antifungal activity of the two proteins on either Candida species was noted. The results imply that the variable expression of the fungicidal activity of lactoferrin and lysozyme on Candida species may modulate the oral carriage of yeasts in a complex manner.

Topics: Antifungal Agents; Apoproteins; Candida; Candida albicans; Candidiasis; Humans; Lactoferrin; Mouth Mucosa; Muramidase; Regression Analysis

A detoxified derivative of endotoxic lipopolysaccharides (LPS), monophosphoryl lipid A (MPL), which is capable of inducing nonspecific resistance against several infectious organisms, was tested for its capacity to activate peritoneal macrophages (M phi) from young and immunodeficient aging BALB/c and C3H/HeN mice. Superoxide generation and hydrogen peroxide release by M phi from aging mice were elevated following intraperitoneal injection with 25 micrograms of LPS or MPL, although they did not reach the peak levels achieved in LPS or MPL-treated young mice. Nitroblue tetrazolium reduction (NBT) by peritoneal M phi from aging C3H/HeN mice treated with MPL was higher than that in control aging mice, equalling that from MPL-treated young mice. LPS, its toxic counterpart, however, failed to increase NBT reduction in either group. MPL enhanced lysozyme activity in M phi from both aging and young C3H/HeN mice above initial control levels. On the other hand, LPS suppressed lysozyme activity in M phi from young, but not aging mice. Phagocytosis of Candida albicans by M phi from BALB/c mice was increased in both groups when stimulated by MPL, but not LPS. Similarly, MPL enhanced the ability to kill Candida in both aging and young BALB/c mice. This effect was not seen with LPS. Thus, a detoxified derivative of LPS was found capable of activating the respiratory burst, NBT reduction, elevating lysozyme activity, as well as phagocytosis and killing of Candida in murine peritoneal M phi from both young and aging mice.

Topics: Aging; Animals; Candidiasis; Hydrogen Peroxide; Immunity, Cellular; Immunotherapy; Lipid A; Lipopolysaccharides; Macrophages; Male; Mice; Muramidase; Oxygen Consumption; Phagocytosis; Superoxides

Topics: Animals; Candidiasis; Drug Therapy, Combination; Injections, Intradermal; Injections, Intramuscular; Injections, Intraperitoneal; Injections, Intravenous; Male; Mice; Muramidase; Rabbits; Tetracycline

Topics: Adolescent; Adult; Aged; Bacterial Infections; Burns; Candidiasis; Child; Child, Preschool; Female; Humans; Infant; Kidney Transplantation; Leukocytes; Male; Middle Aged; Muramidase; Neutrophils; Periodicity; Peroxidases; Phagocytes; Phagocytosis; Sepsis; Transplantation, Homologous; Wound Infection

Topics: Candida; Candidiasis; Hodgkin Disease; Humans; In Vitro Techniques; Leukemia; Leukocytes; Lymphoma; Multiple Myeloma; Muramidase; Neoplasms; Neutrophils; Peroxidases; Phagocytosis; Polycythemia Vera