Fungal cell walls

Intrinsic (natural, innate) resistance. In one form of intrinsic resistance, the fungal cell wall (see Chapter 2) is considered to present a barrier to exclude or, more likely, to reduce the penetration by biocide molecules. The evidence to date is sketchy but the available information tentatively links cell wall glucan, wall thickness and consequent relative porosity to the sensitivity of Saccharomyces cerevisiae to chlorhexidine. 

IV. PARASITISM. Lysis by hydrolytic enzymes excreted by microorganisms is a well-known feature of mycoparasitism. Chitinase and P-l,3 glucanase (laminarase) are particularly important enzymes secreted by fungal mycoparasites capable of degrading the fungal cell wall components, chitin, and P-1,3 glucan (131-134). 

S. Bartnicki-Garcia and E. Lippman. Fungal cell wall composition. Handbook of Microbiology (A. L. Laskin and H. L. Lechvaluer, eds.). Chemical Rubber, Cleveland. Ohio. 1973, p. 229. 

F. Paris, J. Dexheimer, and F. Lapeyric, Cytochemical evidence of a fungal cell wall alteration during infection of Eucalyptus roots by the ectomycon hizal fungus Cenococcum geophUum. Arch Microbiol. 159 526 (1993). 

Sivan, A. and Chet, I. (1989). Degradation of fungal cell walls by Litic enzymes of Trichoderma harzianum , Journal of Genetic Microbiology, 135, 675-682. 

Collectins Alveolar type II cells and non-ciliated bronchiolar epithelial cells Bacterial and fungal cell walls and viruses Enhance phagocytosis of macrophages and neutrophils activating cells Cigarette smoke decreases the production of collectin [48] ozone decreases function [49]... 

C-n.m.r. spectroscopy is useful in monitoring the purity of polysaccharide preparations. Similarly, in a multicomponent, biological system, such as exists in fungal cell-walls, the varying proportion of each polysaccharide can be gauged, once characteristic signals have been identified. 

Caspofungin acetate (9 Cancidas ) E eumocandin Bo Lipopeptide Semi-syntiietic NP Microbial Antifungal Inhibits fungal cell wall synthesis 180-186... 

Anidulafimgin (23 Echinocandin B (24) Lipopeptide Semi-synthetic Microbial Antifungal Inhibits fungal cell wall 279-293... 

Deoxymulundo-candin (158) Echinocandin- type antifungal antibiotic Aminocandin (NXL-201, IP960, HMR-3270)(159) Antifungal (Candida sp. infections) Targets the glucan in fungal cell walls Phase I Novexel 825-827... 

Pharmacology Micafungin is a semisynthetic lipopeptide (echinocandin) synthesized by a chemical modification of a fermentation product of Coleophoma empetri F-11899. Micafungin inhibits the synthesis of 1,3- -D-glucan, an essential component of fungal cell walls, which is not present in mammalian cells. Pharmacokinetics ... 

Figure 1. Hypothetical scheme of events leading to race-cultivar specific resistance or susceptibility in the rust system. If the substrate specificity of the fungal cell wall degrading enzymes (e.g., pectinases) is suitable for degradation of a specific host cell wall component (e.g., partly esterified pectin), endogenous suppressors will be produced which prevent the elicitor induced lignification response, thus leading to susceptibility.

Caspofungin is the first of a new class termed the echinocandins. It was approved in the US and in Europe in 2001. It shows activity against infections with Aspergillus and Candida, and works by inhibiting p(, 3)-D-Glucan of the fungal cell wall. Compared to amphotericin B, caspofungin seems to have a relatively low incidence of side-effects. 

Mechanism of Action An imidazole derivative that changes the permeability of the fungal cell wall. TherapeuticEffect Inhibits fungal biosynthesis of triglycerides, phospholipids. Fungistatic. 

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