DNA Fingerprinting of Candida Isolates from Institutionalised HIV/AIDS Orphans

Objective: To verify through DNA fingerprinting, whether there is a cross-infection of oral yeasts between HIV/AIDS children living in homes for abandoned/orphaned children. Epidemiological studies on infecting agents in a specific geographical area, require the identification to sub-species level in order to understand the pathogenicity, origin and modes of transmission. In a recent survey on the oral yeast carriage of institutionalised HIV/AIDS children, the prevalence of C. albicans and C. dubliniensis differed significantly from what was previously found in adult HIV/AIDS patients. This was suggestive of a possible cross-infection between the children in these homes. Methods: DNA extracted from 25 C. albicans and 12 C. dubliniensis isolates were fingerprinted, with the Ca3 and Cd25 probes, respectively. Fingerprinting patterns were analysed and dendrograms constructed, using Dendron software. Results: None of the fingerprinted strains were from children with clinically detectable candidiasis. In one home only, two isolates of C. albicans obtained from two different children, shared an identical fingerprinting pattern, while in another home two children had C. dubliniensis isolates that were identical. The fingerprinting results further revealed five isolates that were phenotypically identified as C. dubliniensis, to be C. albicans. In six children, two isolates of C. albicans that appeared distinctly different based on colony morphology were obtained per patient. Nevertheless, these pairs of isolates had identical or highly similar Ca3 fingerprinting patterns, with a maximum of one to two band differences in the hypervariable region of the Ca3 patterns. Conclusion: The results revealed a limited sharing of commensal strains of C. albicans and C. dubliniensis among asymptomatic HIV/AIDS children living in close proximity. This work was supported by a MRC grant to EB.