A New Method of Antibiotyping Yeasts for Subspecies Discrimination and Distribution in Human Clinical Specimens

A study of the antibiotypes of 764 isolates of the genera Candida and Torulopsis from different clinical specimens is reported. The typing method was based on the susceptibility results obtained by the standardized and partially automated kit ATB-Fungus (API-bioMérieux), giving to each strain a code of six figures, according to these criteria: susceptibility to 5-fluorocytosine, amphotericin B, nystatin, miconazole, econazole, and ketoconazole. Candida albicans serotypes were determined by the Candida Check test (Iatron, Japan). Twenty-six antibiotypes were found in C. albicans (482 isolates), 21 types in serotype A, and 15 in serotype B strains. Candida parapsilosis (115 isolates) was divided into 11 antibiotypes, Torulopsis glabrata (53 isolates) into five, Candida guilliermondii (36 isolates) into 10 and Candida tropicalis (31 isolates) into eight. Depending on the sample origin, 000000 (susceptibility to all the antifungals tested) was the predominant C. albicans antibiotype (92.9% of blood isolates, 41.2% of vaginal isolates, 33.3% of respiratory isolates, 31.01% or oral and digestive tract isolates, and 25.0% of nail and skin isolates). No predominant antibiotypes were found in strains from respiratory tract, skin ad nails. A reproducibility close to 99% was found with the test. Simplicity and standardization could make this method useful for typing Candida and Torulopsis isolates.