Biofilm Formation and Antifungal Susceptibility of Candida Isolates from Various Clinical Specimens

Abstract

Authors' contributions This work was carried out in collaboration between the two authors. Author SAM planned and designed the study, wrote the protocol, collected the samples, performed the practical laboratory activities, participated in the interpretation of the results and analysis, drafted and critically revised the manuscript. Author ZZA participated in planning and designing the study, sample collection, performing the practical laboratory activities, participated in the interpretation of the results. Both author read and approved the final manuscript. ABSTRACT Background: Candida species are now recognized as major causative agents of hospital-acquired infection. Aims: To evaluate the species distribution, biofilm formation,and antifungal susceptibility (amphotericin B, ketoconazole, and fluconazole) of Candida isolates. Place and Duration of Study: This is a Six-months Cross sectional study conducted in Al-ansar hospital, Al-Madinah, Saudi Arabia. Methodology: One hundred and three isolates of Candida spp. were cultured on Sabouraud dextrose agar (SDA). Candida spp. were identified by four standard methods, CHROMagar candida, cornmeal agar, germ tube test and API 20C. Detection of Biofilm formation was done by microtitre plate and antifungal susceptibility testing was done by disc diffusion. Results: C. albicans was the most common species 61%, followed by C. tropicalis 25%, C. lusitanaie 5%, C. parapsilosis 4%, C. glabrata 4% and C. famata 1%. Biofilm formation was found to occur most frequently among non-albicans spp.(70%) than C. albicans (46%). All 591 isolates were sensitive to amphotericin B and ketoconazole. Resistance to fluconazole was found in 22.5% of non-albicans spp. and 5% of C. albicans isolates. Conclusion: The present study proved that C. albicans is still the major isolate from urinary, vaginal and respiratory samples but non-albicans spp. predominate in the blood samples and from plastic devices. The non-albicans spp. were more biofilm -producers compared to C. albicans and C. tropicalis showed the highest score of biofilm intensity (grade 4+). The species isolated are less susceptible to fluconazole.