CORRELATION BETWEEN IN-VITRO SUSCEPTIBILITY OF CANDIDA-ALBICANS AND FLUCONAZOLE-RESISTANT OROPHARYNGEAL CANDIDIASIS IN HIV-INFECTED PATIENTS

Twenty-five patients seen consecutively at an HIV outpatient clinic wh o had clinical evidence of oropharyngeal candidiasis and two or more o ral swabs positive for yeasts on culture were studied retrospectively. For each of the 65 isolates susceptibility to fluconazole was evaluat ed by the disk diffusion test and determination of the minimal inhibit ory concentration (MIC). A correlation was sought between clinical res istance and in vitro susceptibility data. Seven patients were non-resp onders and 19 were responders (one patient figuring in both groups). S ignificant differences were observed between the two groups with respe ct to the median interval after the diagnosis of AIDS (27 months in no n-responders and 2 months in responders; p = 0.001), the median CD4+ c ell count (6 and 21 cells/mm(3) respectively; p = 0.005) and the media n number of previous episodes of oropharyngeal candidiasis treated wit h fluconazole (13 and 2 episodes respectively; p = 0.001). Candida alb icans was identified in 64 of 65 cultures. The correlation between MIC values and diameters of inhibition was good (r = 0.85; p < 0.001). Th e degree of in vitro susceptibility of the isolates to fluconazole sho wed a significant difference between non-responders and responders (me an inhibition diameters 13 and 36 mm respectively; p < 0.001) with a t entative cut-off value of 25 mm. An advanced stage of HIV infection an d previous exposure to fluconazole could be risk factors for the devel opment of fluconazole-resistant oropharyngeal candidiasis. Candida alb icans strains with decreased in vitro susceptibility to fluconazole we re responsible for the clinical resistance which could be predicted by a simple disk diffusion test.