Antifungal susceptibility profile and biofilm production of Candida spp. isolated from catheterised patients with urinary tract infection

Abstract

BACKGROUND: Candida species, which are present as normal flora in healthy individuals, are known to cause opportunistic infections with high rates of mortality, especially in immunocompromised individuals. Urinary tract infection (UTI) is the most common type of nosocomial infection, and about 10%-15% of them are due to Candida species. Catheter-associated infections due to Candida spp. are mainly due to biofilm formation.OBJECTIVE: This study aims to speciate Candida isolates from catheterised patients with UTI infection and to compare the antifungal susceptibility pattern with their biofilm production.MATERIALS AND METHODS: A total of 55 Candida species were isolated from the urine samples of catheterised patients with UTIs over a period of nine months. Patients' demographic details and risk factors were collected. All the isolates were identified and confirmed by routine phenotypic and genotypic techniques. The rare species that could not be identified by routine techniques were identified by sequencing the internal transcribed spacer region. Biofilm production was detected by tube method, and the antifungal susceptibility testing was done by broth microdilution method (CLSI M27-A3 guidelines).RESULTS: In our study, 55 Candida species were identified, among which the most predominant species was found to be Candida tropicalis 23 (42%). Among 48 biofilm producers (87.2%), only 2 (4.1%) isolates of Candida albicans and 3 (6.2%) isolates of C. tropicalis were resistant to Amphotericin B and Fluconazole. The MIC values for Amphotericin B, Fluconazole and Itraconazole were high in both Candida auris (2) and Candida lusitaniae (1), although one isolate of each species was a potent biofilm producer. In Candida catenulata (4), three isolates had high MIC value for Amphotericin B and two isolates had high MIC value for Itraconazole and three isolates produced biofilm.