GENETIC-VARIABILITY OF CANDIDA-ALBICANS IN HIV-INFECTION

Oral candidiasis is the most common oral manifestation of HIV infectio n, but it is unclear whether, in addition to immune dysfunction, this predisposition is related to changes in the biotypes or genotypes of i nfecting Candida. The objective of this study was to compare the genet ic variability of Candida albicans isolated from 50 HIV infected patie nts (25 Candida carriers and 25 candidiasis patients) and 50 age and c andidiasis matched control subjects. Candidal DNA was extracted, purif ied, cleaved with Bg/II and electrophoresed on agarose gels to reveal restriction fragment length polymorphism (RFLP) banding patterns. Anal ysis of the RFLP patterns revealed a total of 16 genotypes that could reproducibly be identified: designated genotypes A to P. Genotypes A a nd B predominated, accounting for 48 per cent and 30 per cent, respect ively, of all isolates analysed. C. albicans isolated from control sub jects showed comparatively little genetic diversity, regardless of the presence of candidiasis. In contrast, isolates from HIV infected pati ents indicated an increase in the number of unique, genetically divers e genotypes and a reduction in the proportion of genotype B isolates, especially in HIV candidiasis patients (P<0.05). This apparent selecti on of Candida isolates in HIV infection may be associated with the eme rgence of strains with an enhanced ability to cause disease in the pre sence of immune dysfunction.