Prevalence and antifungal susceptibility of vaginal yeasts in outpatients attending a gynecological center in Ancona, Italy

Between February 1993 and May 1994 we studied the prevalence of fungal vulvovaginitis among women attending the Obstetric and Gynecology Clinic of the University of Ancona. Out of the 222 patients, 18 (8.2%) women had symptomatic vaginitis and 24 (10.8%) were carriers. Candida albicans was the species most frequently isolated (44.2%), followed by Torulopsis glabrata (28%) and Saccharomyces cerevisiae (16.2%), from symptomatic and carrier patients. The activity of acid proteinase was determined for C. albicans isolated from both symptomatic and carrier patients. All 13 carriers showed low activity for aspartyl proteinase (score 1+), while 5 of 6 symptomatic patients showed higher activity (score 2+), with a significant difference (p = 0.026). In general, isolates of T. glabrata and S. cerevisiae were less susceptible in vitro to fluconazole than isolates of C. albicans. We did not find any differences in fluconazole MIC results among the C. albicans strains isolated from symptomatic and carrier patients. On the other hand, the fluconazole MICs of T. glabrata and S. cerevisiae isolates showed statistically significant differences between symptomatic and carrier patients (p = 0.009 and p = 0.000, respectively). The differences in proteinase secretion between the isolates from symptomatic and carrier patients suggest a correlation between proteinase production and vaginal candidiasis caused by C. albicans. Torulopsis glabrata, however, was found to be the most common causative agent of vaginitis (7 out 19 episodes), followed by C. albicans (6 out of 19 episodes). Due to the varying patterns of antifungal susceptibility, mainly to fluconazole for the yeast isolates considered in this study, an in vitro susceptibility testing program might be useful for monitoring the outcome of this infection.