Molecular genotyping of Candidaalbicans isolated from different sites may trace the etiological infection routes: Observation in China

Abstract

Background: Invasive candidiasis is a growing concern worldwide, especially in immunocompromised patients, including ICU patients.Objectives: As Candida albicans is the leading cause of candidaemia, it is important to investigate the evolution of C. albicans in patients with candidaemia. Methods:We analysed 238 strains of C. albicans isolated from different body sites.Antifungal susceptibility testing, CAI loci genotyping and multilocus sequence typing (MLST) of all isolates were performed. The relationships among the total isolates that differed in sequence at only one of the seven housekeeping gene loci were analysed using eBURST.Results: Multilocus sequence typing analysis in 238 isolates by combining seven housekeeping alleles revealed 175 diploid sequence types, in which 84 were newly identified. eBURST analysis for these data recognised 19 clonal complexes (CCs) and 79 singletons. Besides, seventy-three CAI genotypes were identified. Blood isolates showed maximum genotypes (49), and the dominant genotypes were CAI 17-21 and CAI 21-21. Oral isolates possessed 25 CAI genotypes, and the dominant genotypes were CAI 17-21 and CAI 21-21 as well. Since isolates with CAI allele numbers <30 showed easier transmission, CAI 17-21 and CAI 21-21 were the most frequently transmitted. Finally, the CAI genotypes were classified into six groups.Conclusions: This work revealed the oral and blood strains isolated from the patients with candidaemia in ICU shared the identical dominant CAI genotypes. Our data expanded the C. albicans MLST database and helped with understanding the evolution and spread of invasive candidiasis.

Candida albicans Multilocus Sequence Typing Clade I Contributes to the Clinical Phenotype of Vulvovaginal Candidiasis Patients

“…The MLST used in this study is based on nucleotide sequence analysis of the internal regions of multiple independent housekeeping genes and has proven to be a useful method for epidemiological investigation of clinical isolates of C. albicans. MLST studies have been conducted on C. albicans isolates from the digestive tract, blood infections, oral leukoplakia, and vaginal secretions (33)(34)(35)(36)(37). In addition, MLST has been applied widely to study nosocomial infection, which is important for the prevention and control of infection (38,39).…”