Requirement for the Candida albicans FAS2 gene for infection in a rat model of oropharyngeal candidiasis

• Published in: Microbiology (Society for General Microbiology) Vol. 142; no. 9; pp. 2509 - 2514
• Main Authors: Zhao, Xiao-Jiong, McElhaney-Feser, Gail E, Bowen, William H, Cole, Michael F, Broedel, Sheldon E., Jr, Cihlar, Ronald L
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.09.1996; Society for General Microbiology
• Subjects: Alleles; Animals; Biological and medical sciences; Blotting, Southern; Candida albicans - genetics; Candida albicans - growth & development; Candida albicans - pathogenicity; Candidiasis, Oral - genetics; Cloning, Molecular; Culture Media; Fatty Acid Synthases - genetics; Fatty Acid Synthases - metabolism; Fatty Acids - metabolism; Fundamental and applied biological sciences. Psychology; Microbiology; Mutagenesis, Insertional; Mycology; Pathogenicity, host-agent relations, miscellaneous strains, epidemiology; Plasmids; Polysorbates - metabolism; Rats; Rats, Sprague-Dawley; Sequence Deletion; Candida albicans; Animal model; Candidiasis; Yeast; Mycosis; Rat; Virulence; Rodentia; Host agent relation; Oropharynx; Fungi; Infection; Oral cavity; Vertebrata; Mammalia; Animal; Infectivity; ENT disease; Fungi Imperfecti; Thallophyta
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-142-9-2509

Department of Microbiology and Immunology, Georgetown University, Washington, DC 20007, USA Department of Dental Research, University of Rochester, Rochester, NY, USA ChekTec Corporation, Baltimore, MD 21227, USA 4 Author for correspondence: Ronald L. Cihlar. Tel: +1 202 687 1136. Fax: +1 202 687 1800. e-mail: rcihla01@gumedlib.dml.georgetown.edu ABSTRACT The virulence of Candida albicans strains deficient in fatty acid synthase activity by virtue of disruption/deletion of the FAS2 gene was examined in a rat model of oropharyngeal candidiasis. The FAS2 alleles of C. albicans CA14 ( ura3::imm434 / ura3::imm434 ) were sequentially disrupted with a cassette that included a portion of FAS2 from which a 984 bp fragment containing the FAS condensing reaction domain was deleted and replaced with hisG-URA3-hisG sequences. Verification of fatty acid synthase inactivation was obtained from assays of enzyme activity. Strains in which a single allele was disrupted (CFD1 and CFD3) exhibited an approximately 20% reduction in activity, when compared to wild-type. In addition, fatty acid synthase activity was abolished in a FAS2 null mutant strain (CFD2), and growth of CFD2 occurred only when the growth medium was supplemented with Tween 40 and certain fatty acids. Strain CFD2 was avirulent in the rat model, indicating that fatty acid synthase activity is required for C. albicans oropharyngeal infection. Strains with a single FAS2 allele disruption colonized the oral cavity, but the number of cells recovered from infected animals was approximately fivefold less than for the parental strain. The results suggest that FAS may be exploited as a possible target for the development of new antifungal agents. Keywords: Candida albicans , FAS2 , null mutants, avirulence, oropharyngeal