Prevalence and virulence factors of Candida spp. associated with blow flies

• Main Authors: Wimonrat GunTang, Nathamon Kamonvoradej, Chitchanok Chomchat, Sangrawee Suriyakan, Sangob Sanit, Jintana Wongwigkarn, Nophawan Bunchu, Damrongpan Thongwat, Supaporn Lamlertthon
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2017-05-01
• Series: Asian Pacific Journal of Tropical Biomedicine
• Subjects: Blow flies; Candida albicans; β-Hemolysin; Phospholipase; Antifungal resistance
• Online Access: http://www.sciencedirect.com/science/article/pii/S2221169116304324

Objective: To investigate the prevalence of Candida spp. and the virulence factors of Candida albicans (C. albicans) isolated from external surfaces of blow flies collected from Mae Sot, Tak Province, Thailand. Methods: The blow flies were collected by sterile sweep nets from three areas in Mae Sot. Yeast isolation was first performed on Sabouraud dextrose agar (SDA) supplemented with chloramphenicol and cycloheximide. The yeast isolates were then identified by using chromogenic agar, a yeast identification test kit, a germ tube formation test and a carbohydrate utilization test. The β-hemolysis was determined on 7% sheep blood agar, while phospholipase activity was measured on SDA agar supplemented with 10% egg yolk suspension. Antifungal susceptibility testing was determined by broth micro-dilution testing against ketoconazole and amphotericin B. Results: The prevalence rate of Candida spp. on the external surfaces of the blow flies was 78.1%. All C. albicans isolated from the blow fly demonstrated β-hemolysin and potent phospholipase activities and 47.1% of C. albicans were resistant to ketoconazole with MIC values 128 μg/mL. Conclusions: The results indicate that blow flies could play an essential role in the transmission of potentially pathogenic and antifungal resistant C. albicans into the environment. Further investigation on other virulence factors and genetic relatedness among isolates from the blow flies, the environment and clinical specimens is required to confirm this role.