title: Melanization of a meristematic mutant of Fonsecaea monophora increases tolerance to stress factors while no effects on antifungal susceptibility.
abstract: Melanin is a complex polymer, which is widely distributed in nature, and is known as an important virulence factor in opportunistic and pathogenic fungi. In this study, three melanin mutants of Fonsecaea monophora from a case of chromoblastomycosis were generated from a parent strain that lacked hyphal morphology but was meristematic instead. Two albino mutants, one of which (CBS 125187) produced secreted melanin and another (CBS 125149) lacked melanin, grew faster than a mutant with cell-wall-associated and secreted melanin (CBS 125188) and than the meristematic parent strain (CBS 122845) (P < 0.05). The albino strains were also more sensitive to low pH, high UV radiation, and oxidative stress (P < 0.05). However, susceptibility testing against eight antifungal agents showed no statistical difference (P > 0.05). The discovery of three melanin mutants of a single meristematic mutant provided an alternative way to study the role of cell-wall-associated and secreted melanins in the pathogenesis of black fungi.
authors.affiliation: Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, 107 West Yanjiang Rd, Guangzhou, 510120, China.
authors.forename: Jiufeng
authors.initials: J
authors.lastname: Sun
authors.forename: Junmin
authors.initials: J
authors.lastname: Zhang
authors.forename: M J
authors.initials: MJ
authors.lastname: Najafzadeh
authors.forename: Hamid
authors.initials: H
authors.lastname: Badali
authors.forename: Xiqing
authors.initials: X
authors.lastname: Li
authors.forename: Liyan
authors.initials: L
authors.lastname: Xi
authors.forename: G S
authors.initials: GS
authors.lastname: de Hoog
mesh_terms: D000369:Aged, 80 and over; D000935:Antifungal Agents / Q000494:pharmacology*; D001203:Ascomycota / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D001483:Base Sequence; D002862:Chromoblastomycosis / Q000382:microbiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008543:Melanins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D018384:Oxidative Stress; D010858:Pigmentation / Q000235:genetics; D017422:Sequence Analysis, DNA; D013312:Stress, Physiological / Q000235:genetics*; D014466:Ultraviolet Rays
chemical_list: D000935:Antifungal Agents; D008543:Melanins