VARIATIONS IN FLUCONAZOLE SUSCEPTIBILITY AND DNA SUBTYPING OF MULTIPLE CANDIDA-ALBICANS COLONIES FROM PATIENTS WITH AIDS AND ORAL CANDIDIASIS SUFFERING ONE OR MORE EPISODES OF INFECTION

Five Candida albicans colonies from each infection in AIDS patients re ceiving fluconazole therapy for oropharyngeal candidiasis over a 2-yea r period were evaluated by antifungal susceptibility testing and DNA s ubtyping, and the results were correlated with clinical response to de termine the occurrence of clinically significant Selection of more-res istant C. albicans over multiple infections, A total of 534 C. albican s isolates were obtained from 38 patients who exhibited 84 episodes of infection, Antifungal susceptibility testing revealed that the MICs f or 93% of the isolates were less than or equal to 8.0 mu g/ml and the MICs for 7% of the isolates were greater than or equal to 64 mu g/ml. DNA subtyping revealed 70 different subtypes, with 78% of patients wit h one infection exhibiting one DNA subtype and 80% of patients with mo re than one infection exhibiting multiple DNA subtypes, Also, patients who had multiple infections had lower CD4 counts than those with sing le infections, Differences between the single-infection group and the multiple-infection group regarding the number of DNA subtypes and CD4 counts were both statistically significant, Of the 74 evaluable infect ions all were successfully treated with regular-dose (100-mg/day) fluc onazole, except for three patients who ultimately responded to higher- dose fluconazole, Only one patient may have shown clinically significa nt selection of a more-resistant C. albicans strain over multiple cour ses of treatment, Interestingly, MICs reached only 8.0 mu g/ml, even t hough doses of 400 mg of fluconazole were necessary for clinical cure.