Genotypic variability and antifungal susceptibility of Candida tropicalis isolated from patients with candiduria.

BACKGROUND

Candida tropicalis is an emerging major human pathogen in nosocomial infections, and it is considered the second or third species of Candida most isolated from urine cultures.

AIMS: The study aimed at characterizing genotypically C. tropicalis strains from patients with candiduria in a university hospital, and assessed the antifungal susceptibility profile.

METHODS

The study was conducted with hospitalized patients who developed urinary tract infection from C. tropicalis from June 2010 to June 2011 at the Grande Dourados University Hospital of the Federal University, Dourados, MS, Brazil. Susceptibility to the antifungal agents amphotericin B and fluconazole was determined by broth microdilution. The genotypic variability of isolates of C. tropicalis was analyzed by microsatellite markers and RAPD-PCR.

RESULTS

Only one isolate was resistant to amphotericin B (MIC→16μg/ml); the others were susceptible to fluconazole and amphotericin B. The genotypic variability by RAPD-PCR resulted in distinct profiles for RAPD markers. A total of 10 alleles were observed for the microsatellite loci, URA3 and CT14, which were grouped differently, and four associations were observed for locus URA3 and eight for locus CT14.

CONCLUSIONS

C. tropicalis isolates from urine were susceptible to the antifungal agents tested. The genotyping techniques make possible proving the similarity and genetic diversity among isolates of C. tropicalis involved in nosocomial infections. This knowledge is important for the control and prevention of nosocomial infections caused by this yeast species.