Idiosyncratic response of yeasts, recovered from oropharyngeal lesions of HIV patients, to prophylactic antifungal agents, in South Western Uganda

Abstract

Background: Although cutting edge technologies have advanced overall knowledge of microbial infections, what microorganisms will do when challenged with surface active agents is incompletely understood and understanding the characteristic uniqueness of an organism when challenged with antimicrobial agents derails antibiotic stewardship programs in resource limited settings. T his study was therefore designed to determine the idiosyncratic in-vitro response of yeast strains, challenged with selected routine antifungal agents used for routine prophylactic management of HIV infected Methods: A total of 304 (235 females and 69 males) patients with different conditions were recruited. The analysis performed included: cultivation on Sabouraud Dextrose Agar, Corn Meal Agar, Potato Dextrose Agar, germ-tube test, chlamydospore production, test for ability to grow at 45 o C. For further morphologic identification, yeasts were grown on CHROMagar Candida medium at 37 + 2 0 C for 24-48 hours and sub-cultured on Pal’s agar. The minimum inhibitory concentration (MIC) of the isolates were determined by the E-test stable agar gradient method (AB BIODISK, Solna, Sweden) Results: The 304 (235 females and 69 males) recruited patients with different oral lesions consented to this study and 304 sample surveyed was guided by the upper limit required to give 95% level of confidence at an expected prevalence of about 74% (Agwu et al, 2008) using : Sample size (N) = Z 2 P (100-P)/D2 giving 296 samples, (Epi-info version 3.2 data-base; 1995), where Z is a constant given as (1.96), P is expected prevalence (74%), and D is acceptable error (5%). Informed consent was sought and obtained from the following: Uganda National Council of Science and Technology, Kampala International University Research and Ethics Committee, HIV patients of The AIDS Support Organizations,. Conclusion : Candida albicans remain significantly susceptible to tested antifungal agents. Emerging dose dependent susceptibility in non albicans oropharyngeal yeast strains is interesting in this era of increasing treatment failures due to drug resistance. Pattern of resistance recorded may suggest significant contribution of yeast in the recurrent or delayed oropharyngeal lesions of HIV population studied. Sustained surveillance with MIC which impacts treatment outcome is recommended