Phenotypic characterization and adhesive properties of vaginal Candida spp. strains provided by the CHU Farhat Hached (Sousse, Tunisia).

Background: Vulvovaginal candidiasis is a common infection among women worldwide, being Candida albicans the most commonly isolated species. Therefore, controlling this opportunistic yeast is one of the key factors for reducing nosocomial infection.

Aims: We investigated several virulence properties of 28 vaginal strains of Candida isolated from Tunisian women suffering from vulvovaginitis. We also analyzed the virulence properties of a clinical Candida krusei strain and five Candida reference strains.

Methods: Candida strains were subjected to microscopic analysis and culture in Candida ID2 chromogenic medium. The adhesive properties of these strains were estimated by the microtiter plate - the safranin-staining - and the Congo red agar (CRA) methods, for determining yeast ability to form biofilms on biomaterials used in urinary catheter manufacturing. Their potency to produce hydrolytic enzymes was also studied.

Results: Our results showed that nine out of the total studied strains produced phospholipase. In addition, very high protease activity was detected in 23 Candida strains. All Candida strains were beta-hemolytic and adhered to polystyrene microtiter plates in varying degrees. Two vaginal C. albicans strains were strongly adhesive to polystyrene and glass slides. Also, our results showed that vaginal Candida strains were more adhesive to the three tested materials than the reference strains.

Conclusions: This study shows the presence of a range of virulence and adhesion factors in clinical isolates of vaginal Candida. Consequently, control and treatment of vaginal candidiasis as a means to prevent biofilm formation on urinary catheters is of crucial importance.