Clonal population structure and genetic diversity of Candida albicans in AIDS patients from Abidjan (Côte d'Ivoire)

We have investigated the genotype at 14 enzyme-encoding loci in 275 isolates of the pathogenic yeast Candida albicans sampled from 42 HIV-positive patients (all but one with AIDS) from Abidjan (Côte d'Ivoire). We separately analyzed the following variables: patient, residence, age, gender, T cell count, hospitalization (yes or no), drug treatment, date of sampling, multilocus genotype, and serotype. The most important factors contributing to the genetic variability of C. albicans are individual patient and gender. Our data manifest that the population size of the parasite is relatively small within each patient, although larger in women than in men, and that, at least for the patients involved in the study, the transmission rate of C. albicans between human adults is very low. Most important is the inference that the prevailing mode of reproduction of C. albicans in natural populations is clonal, so that sexual reproduction is extremely rare, if it occurs at all.

Oropharyngeal candidiasis in AIDS patients from Abidjan (Ivory Coast): antifungal susceptibilities and multilocus enzyme electrophoresis analysis of Candida albicans isolates

Multilocus enzyme electrophoresis (MEE) and in vitro antifungal susceptibility testing were used to investigate the Candida albicans strain diversity in twenty nine AIDS patients from Abidjan (Ivory Coast). All patients were monitored for a first episode of oropharyngeal candidiasis and were randomly clustered into three groups of therapy: ketoconazole, amphotericin B or nystatin. Oral swabs were collected before every treatment, 14 and 30 days after the initiation of the therapy; a total of 67 isolates were investigated. No resistant or less susceptible isolate to any antifungal agent was found despite the emergence of clinical relapses, mainly for patients treated with nystatin or amphotericin B. The MEE analysis revealed 27 different electrophoretic types (ETs). Genetic distances between ETs were statistically analyzed and represented on a dendrogram. The 27 ETs clustered into three groups; in each group, ETs represented variants of the same strain. A segregation of the C. albicans isolates seemed to be as a function of the serotype.