Extensive chromosome translocation in a clinical isolate showing the distinctive carbohydrate assimilation profile from a candidiasis patient

Variation of the electrophoretic karyotype is common among clinical strains of Candida albicans and chromosome translocation is considered one of the causes of karyotypic variation. Such chromosome translocations may be a mec hanism to confer phenotypic diversity on the imperfect fungus C. albicans. A clinical strain, TCH23, from a vaginal candidiasis patient shows distinct carbohydrate assimilation profile, serotype B, no chlamydospore formation and an atypical karyotype (Asakura et al, 1991). To examine the taxonomic r elationship among C. albicans, Candida dubliniensis and this strain, we seq uenced the internal transcribed spacer 1 (ITS1) of nuclear ribosomal DNA. T he ITS1 sequence of TCH23 was identical with that of C. albicans but not of C. dubliniensis. Thus, strain TCH23 was classified as a variant of C albic ans with an atypical phenotype. The chromosomal DNAs of this strain were re solved into 13 bands on pulse-field gel electrophoresis (PFGE). Using DNA p robes located at or near both ends of each chromosome of C. albicans, we in vestigated the chromosome organization of this strain. Referring to the Sfi I map of C albicans 1006 (Chu et al, 1993), we found that seven chromosomal DNA bands in strain TCH23 were reciprocal chromosome translocations. One h omologue from chromosomes 1, 2 and 6 and both homologues from chromosomes 4 and 7 participated in these events. One translocation product was composed of three SfiI fragments, one each from chromosomes 2, 4 and 7. We deduced the breakpoints of chromosome translocation from the physical map of this s train; between 1J and 1J1, between 2A and 2U, both ends of 4F2, between 6C and 6O and both ends of 7F. Copyright (C) 2001 John Wiley & Sons, Ltd.