Distribution of Candida Species and Molecular Typing of C. albicans Isolates in a Mexico City Tertiary Care Hospital from 2011 to 2013

Abstract

The incidence of yeast infections has increased significantly over the past few years, constituting a leading cause of morbidity and mortality among hospitalised patients. The rapid identification of candidiasis is important for the clinical management of patients and to facilitate tracing the sources of infections in hospitalized patients. Here, we report a retrospective, single-centre study of Candida spp. distribution and antifungal susceptibility from January 2011 to May 2013 at a hospital in México City, regarding the importance of elucidating the identity of the infection-causing Candida species in order to improve prophylactic measures and treatment. Clinical data were collected from patient medical records and the laboratory database. Isolates were initially identified using standard mycology techniques, and then confirmed by PCR-based system using amplification of intergenic spacers (rDNA ITS) and restriction length polymorphism of PCR products after sequence-specific enzymatic cleavage (PCR-RFLP). We observed no shift from C. albicans to non-albicans Candida species: Candida albicans (73.7%) was the most prevalent species isolated, while C. dubliniensis was not identified in this study. Antifungal susceptibility was determined using FUNGITEST ® ; 17.4% of C. albicans isolates were resistant to fluconazole and 21.7% to itraconazole. Multiplex PCR microsatellite analysis of the clinical C. albicans isolates using primers for the CAI, CAIII and CAVI loci identified 29 different alleles for CAI, 8 alleles for CAIII and 31 for CAVI. The combined discriminatory power of these three microsatellites was 0.98, which was considered reliable for molecular typing. Genetic analysis of these isolates revealed a clonal population with a total of 62 genotypes from the examined isolates.