title: Alteration of cell wall composition leads to amphotericin B resistance in Aspergillus flavus.
abstract: An amphotericin B (AmB)-resistant mutant was isolated from a wild-type AmB-susceptible strain of Aspergillus flavus by serial transfer of conidia on agar plates containing stepwise increased concentrations of AmB up to 100 microg ml-1. The acquired resistance of mycelia was specific for polyene-antibiotics AmB, nystatin and trichomycin. Spheroplasts derived from the resistant mycelia were as susceptible to AmB as the wild-type. Chemical analysis of the cell wall revealed that levels of alkali-soluble and -insoluble glucans were significantly higher in the resistant mycelia as compared to those in the wild-type. When resistant mycelia were treated with SDS, they adsorbed as much AmB as wild-type mycelia. These results suggest that alterations in the cell wall components of mycelia, especially 1,3-alpha-glucan and protein complex in the outermost wall layer, lead to AmB resistance in A. flavus.
authors.affiliation: Department of Biological Chemistry, Faculty of Integrated Arts and Sciences, School of Medicine, The University of Tokushima, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Seo
authors.forename: H
authors.initials: H
authors.lastname: Akiyoshi
authors.forename: Y
authors.initials: Y
authors.lastname: Ohnishi
mesh_terms: D000666:Amphotericin B / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology*; D001231:Aspergillus flavus / Q000737:chemistry / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D002473:Cell Wall / Q000737:chemistry; D004352:Drug Resistance, Microbial; D005936:Glucans / Q000737:chemistry; D009154:Mutation; D011135:Polysaccharides, Bacterial / Q000032:analysis; D011188:Potassium / Q000378:metabolism; D013104:Spheroplasts / Q000378:metabolism; D013172:Spores, Fungal / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D005936:Glucans; D011135:Polysaccharides, Bacterial; D000666:Amphotericin B; C045788:alpha-1,3-glucan; D011188:Potassium