ABSTRACT
The aim of this study is to study the epidemiology, the etiology of yeast vaginitis and the rate of incidence of yeast vaginal infection.. Also, to highlight the adherence process and the proteinase production as critical factors affecting the pathogenesis. A total of 500 female patients attending gynaecological out patients clinics of some general hospitals were tested for the presence of yeasts using vaginal swabs from the vagina. History of patients was recorded. The positive cultures were purified and identified according to the conventional yeast identification methods and by using of candifast kits. Adhesion of pathogenic yeast species was tested and observed by scanning electron microscope. Some factors affecting the adhesion of Candida albicans were studied. Also the production of proteolytic enzyme by this species was carried out. Out of the 500 studied cases, 295 [59%] were positive for yeast infection including 170 [57.6%] diabetic; 81[27.5%] postmenopause subjects; 20[6.8%]subjects using oral contraceptives; 18[6.1%] cancer patients and 7[2.4%]Hysterectomy. The identification revealed the presence of nine yeast species belonging to three genera: Candida [7 species], Debaromyces [one species] and Saccharomyces [one species]. Candida albicans was the most prevalent species [131 cases representing 44.4% of the positive cases] followed by Candida lusitaniae and Candida krusei were of moderate occurrence [25 cases [8.5%] and 23 cases [7.8%]. The adherence assay showed that the highest adherence rate [51%] was noted with vaginal epithelial cells collected from diabetic patients. Candida albicans adhesion was the highest 59% +/- 3% [P >/= 0.001, highly significant] compared with the other Candida species. Scanning electron microscopy indicated that fibril structures were prominent with adhesion of C. albicans .yeast concentration of 10[7]. 37C° and pH 3 were the best conditions for peak adhesion of C. albicans. neutral proteases [pH6.5] of C. albicans were released in appreciable amount 685?mol/ml followed by alkaline proteases[pH 8.2] while the least amount recorded was acid proteases[pH 3.5]. attention must be paid to the profoundly increase in the vaginal yeast infection among patients with different predisposing factors. Various yeast etiologic agents and their pathogenesis are explained in this work