Species Distribution, Antifungal Susceptibility, and Molecular Epidemiology of Candida Species Causing Candidemia in a Tertiary Care Hospital in Bangkok, Thailand.

Thanwa Wongsuk,Siriphan Boonsilp,Uraporn Phumisantiphong,Anchalee Homkaew,Daranee Nutalai

doi:10.3390/jof7070577

Thanwa Wongsuk, Siriphan Boonsilp + Show 3 more

Open Access

https://doi.org/10.3390/jof7070577

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Abstract

Candida species represent a common cause of bloodstream infection (BSI). Given the emergence of non-albicans Candida (NAC) associated with treatment failure, investigations into the species distribution, fungal susceptibility profile, and molecular epidemiology of pathogens are necessary to optimize the treatment of candidemia and explore the transmission of drug resistance for control management. This study evaluated the prevalence, antifungal susceptibility, and molecular characteristics of Candida species causing BSI in a tertiary-level hospital in Bangkok, Thailand. In total, 54 Candida isolates were recovered from 49 patients with candidemia. C. tropicalis was the most prevalent species (33.3%), followed by C. albicans (29.6%). Most Candida species were susceptible to various antifungal agents, excluding C. glabrata and C. tropicalis, which had increased rates of non-susceptibility to azoles. Most C. glabrata isolates were non-susceptible to echinocandins, especially caspofungin. The population structure of C. albicans was highly diverse, with clade 17 predominance. GoeBURST analysis of C. tropicalis revealed associations between genotype and fluconazole resistance in a particular clonal complex. The population structure of C. glabrata appeared to have a low level of genetic diversity in MLST loci. Collectively, these data might provide a fundamental database contributing to the development of novel antifungal agents and diagnostic tests.

Highlights

Candida species are important components of the microflora of the human skin, oral and vaginal mucosa, and gastrointestinal tract
C. albicans is the main global cause of bloodstream infection (BSI), non-albicans Candida (NAC) species are of increasing concern in patients with hematological conditions, those who underwent organ transplantation, and those admitted to an intensive care unit (ICU) [6]
This study explored the species distribution, molecular epidemiology, and antifungal susceptibility profiles of Candida species causing candidemia in our hospital

Summary

Introduction

Candida species are important components of the microflora of the human skin, oral and vaginal mucosa, and gastrointestinal tract. The risk factors for Candida BSI include long-term intensive care unit (ICU) hospitalization, central venous catheterization, organ transplantation, recent broadspectrum antibiotic use, and immunodeficiency [4]. Virulence factors such as germ tube formation, adhesins, phenotypic switching, biofilm formation, and hydrolytic enzyme production contribute to the pathogenesis of candidiasis [5]. The multilocus sequence typing (MLST) technique is a widely used molecular typing method in molecular epidemiology for pathogenic Candida species including C. albicans, C. tropicalis, and C. glabrata. This method is based on the analysis of single-nucleotide polymorphisms in housekeeping gene fragments. This method provides insights into different geographical sources, anatomical sources, drug resistance acquisition transmission, and genetic variation patterns

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