Antifungal Testing of Vaginal <i>Candida</i> Isolates in Pregnant Women: A Retrospective, Single-Center Study in Adana, Türkiye

Clinical and mycological data are essential for the optimal management of patients with <i>Candida</i> vaginitis (CV), particularly in cases of (i) azole-resistant <i>C</i>. <i>albicans</i> vaginitis, (ii) recurrent CV, and (iii) CV in pregnant women. The present retrospective single-center study investigated the antifungal activity of six commonly used antifungals against randomly selected vaginal isolates recovered from 68 pregnant women in Adana, Türkiye, including <i>C</i>. <i>albicans</i>, petite <i>C</i>. <i>glabrata</i>, non-petite <i>C</i>. <i>glabrata</i>, and <i>C</i>. <i>krusei</i>, using the disk diffusion method at pH 4 and 7. Furthermore, the antifungal activities of fluconazole and itraconazole were also assessed using the broth microdilution method. For all isolates, the mean inhibition zone diameters were narrower for itraconazole and ketoconazole and larger for miconazole at pH 4 than pH 7 (<i>p</i> < 0.05). For nystatin, zone diameters were wider in <i>C</i>. <i>albicans</i> and petite <i>C</i>. <i>glabrata</i> at pH 4 (<i>p</i> < 0.001 and <i>p</i> < 0.001). Remarkably, clotrimazole was more active at pH 4 than at pH 7, except against non-petite <i>C</i>. <i>glabrata</i> isolates. Based on the broth microdilution results, the resistance rate was higher at pH 4 than at pH 7 in all isolates. <i>Candida glabrata</i> petite isolates exhibited MIC values 2 to 5 times higher than those of the non-petite isolates for both fluconazole and itraconazole. This study highlights the potent activity of topical antifungals (miconazole, nystatin, and clotrimazole) for the treatment of CV in pregnant women and highlights the need to identify petite and non-petite mutants of vaginal <i>C</i>. <i>glabrata</i> isolates to obtain more reliable data and for antifungal susceptibility testing prior to decision-making. The results of the two antifungal susceptibility methods were compared for <i>C. albicans</i> and <i>C. glabrata</i> isolates, and the reliability of the disk diffusion test was discussed.