Point prevalence, microbiology and antifungal susceptibility patterns of oral Candida isolates colonizing or infecting Mexican HIV/AIDS patients and healthy persons

We have conducted a longitudinal study over a 3-year period to address the point prevalence, microbiological characteristics and antifungal susceptibility patterns of yeast isolates colonizing or infecting the oral cavities of 111 HIV-infected (51 adults, 60 children) and 201 non HIV-infected (109 adults, 92 children) Mexican persons. Regarding the epidemiology of oral candidiasis, Candida albicans was the most frequent species isolated. Seventy-one out of 85 isolates from colonized persons were C. albicans (83.5%), 27 isolates of them were from HIV-infected children and 44 from non HIV-infected patients. Sixty-two isolates belonged to serotype A which was the most prevalent serotype of C. albicans. Non-albicans species (Candida glabrata, Candida tropicalis and Candida parapsilosis, and Saccharomyces cerevisiae) were isolated from 16.5% of colonized patients and from 38.5% patients with candidiasis or Candida-related lesions. There were nine episodes of infection or colonization by at least 2 different yeast species. In the case of HIV/AIDS patients, it was determined that yeast carriage was not associated with the number of CD4+ cells or the viral load, but HAART reduced the prevalence of oral candidiasis. Overall, most patients harbored strains in vitro susceptible to fluconazole, however 10.8% of the yeasts were resistant to one or more azole antifungal agents and 29% were intermediate susceptible to them. On the contrary, 5-fluorocytosine was very active against all isolates tested, and amphotericin B was active against 97.9% of them.