Isolation and Detection of Yeast Biofilms From Urine Catheters of Infectious Patients

Background: Recent evidences have revealed that in more than 65% of microbial infections, biofilms have critical roles. The ability of yeasts to form biofilms on surface of medical devices such as urine catheters is an important reason of the capability of these microorganisms to cause human disease. Objectives: The aim of this study was to isolate and identify yeasts on the surfaces of urine catheters and to investigate their ability to form biofilms. Patients and Methods: In this research, 55 urine catheters from patients of ICU award of Army Family Hospital in Tehran (Iran) were assayed. The catheters were taken aseptically to the laboratory for studying biofilms. Then they were sonicated and cultured on Sabouraud dextrose agar, CHROM agar and Corn meal agar. Examination of germ tube, sugar absorption and PCR method by two primers of ITS1 and ITS4 were used to identify pathogenic yeasts. Results: According to the classical methods and molecular techniques, Candida albicans, C. krusei, C. glabrata and C. tropicalis were identified. Conclusions: The results show that yeast biofilms can form on the surface of catheters. Candida species are the yeasts which were isolated from these surfaces of infectious patients. C. tropicalis was the most abundant species which was isolated from the patients of this study.