Genotypic characterization of sequential Candida albicans isolates from fluconazole-treated neutropenic patients.

A polymerase chain reaction (PCR)-mediated genotyping assay for Candida albicans has been developed. By amplification of genomic regions bordered by eukaryotic or prokaryotic repeat-like motifs, differences between C. albicans isolates can be determined. The resolution of this typing procedure is at least as good as that of other genotypic assays. To ascertain the epidemiologic and clinical usefulness of this PCR genotyping, a retrospective analysis of serial C. albicans isolates from neutropenic adults treated with fluconazole was done. By PCR genotyping, 40 strains were detected in 24 patients. Eighteen C. albicans strains were found on multiple samplings in individual patients. It appears that most patients remain colonized with a C. albicans strain of constant genotypic characteristics. However, exceptions were observed. In 7 (29%) of 24 patients, strains deviating from the most frequently encountered type could be identified. All but 1 strain remained susceptible to fluconazole in vitro after treatment in vivo. It was not possible to demonstrate a relation of genotypic variation and antifungal susceptibility changes.