Cryptococcus neoformans isolates from Yaoundé HIV infected patients exhibited intra individual genetic diversity and variation in antifungal susceptibility profiles between isolates from the same patient.

This study investigated the intra individual genetic diversity and the antifungal susceptibility of C. neoformans isolates from Yaoundé (Cameroon) HIV infected patients with cryptococcal meningitis. Twenty five clinical isolates were obtained during a prospective study. Five colonies were randomly collected from each initial sample. The 150 obtained isolates (125 colonies and 25 initial samples) were submitted to serotyping by multiplex PCR. Genotyping analyses were achieved by restriction fragment length polymorphism and mini- and microsatellite length polymorphism. The antifungal susceptibility testing was carried out using the Sensititre Yeast One kit. Seven antifungals were tested: itraconazole, fluconazole, amphotericin B, ketoconazole, flucytosine, posaconazole and voriconazole. The 150 isolates were identified as C. neoformans serotype A and genotype VNI. The microsatellites and minisatellites sequence analyses generated 15 genotypes. Six out of 25 (24%) patients were found to be infected by 2 different genotypes. Antifungal susceptibility showed several profiles: posaconazole (0.015-0.25µg/mL), amphotericin B (0.06-1µg/mL), fluconazole (0.5-16µg/mL), itraconazole (0.008-0.12µg/mL), ketoconazole (0.008-0.12µg/mL), 5-fluorocytosine (0.25-16µg/mL), voriconazole (0.008-0.12µg/mL). It was noticed that isolates from the same patient might present different susceptibility profiles to an antifungal drug with more than 4 dilutions differences. The achieved results high...
Source: Journal of Medical Microbiology - Category: Microbiology Authors: Tags: J Med Microbiol Source Type: research