Analyses of the Global Multilocus Genotypes of the Human Pathogenic Yeast Candida tropicalis

Abstract

Candida tropicalis is a globally distributed human pathogenic yeast, especially prevalent in tropical and sub-tropical regions. Over the last several decades, a large number of studies have been published on the genetic diversity and molecular epidemiology of C. tropicalis from different parts of the world. However, the global pattern of genetic variation remains largely unknown. Here we analyzed the published multilocus sequence data at six loci for 876 isolates from 16 countries representing five continents. Our results showed that 280 of the 2677 (10.5%) analyzed nucleotides were polymorphic, resulting in a mean of 82 (a range of 38–150) genotypes per locus and a total of 633 combined diploid sequence types (DSTs). Among these, 93 combined DSTs were shared by 336 strains, including 10 by strains from different continents. Analysis of Molecular Variance (AMOVA) showed that 89% of the observed genetic variations were found within regional and national populations while < 10% was due to among-country separations. Pairwise geographic population analyses showed overall low but statistically significant genetic differentiation between most geographic populations, with the Singaporean and Indian populations being the most distinct from other populations. However, the Mantel test showed no significant correlation between genetic distance and geographic distance among the geographic populations. Consistent with high genetic variation within and limited variations among geographic populations, results from STRUCTURE analyses showed that the 876 isolates could be grouped into 15 genetic clusters, with each cluster having a broad geographic distribution. Together, our results suggest frequent gene flows among certain regional, national, and continental populations of C. tropicalis , resulting in abundant regional and national genetic diversities of this important human fungal pathogen.

Fusarium Species and Fusarium oxysporum Species Complex Genotypes Associated With Yam Wilt in South-Central China

“…However, long-distance dispersal of asexual spores by natural forces such as wind and by anthropogenic factors such as human travel and yam trade could bring pathogens from one region to another. Similar kinds of genotype sharing have been reported for other plant fungal pathogens and human fungal pathogens, including those in southern China (e.g., Li et al, 2016;Wu J. Y. et al, 2019).…”

Molecular epidemiology of Candida tropicalis isolated from urogenital tract infections

“…Moreover, in the past studies of C. albicans, the isolates obtained from different body sites also showed different genotype distribution patterns (McManus, & Coleman, 2014;Wang et al, 2015). Although genotypes were not related to anatomical sites in Wu et al's analysis (Wu et al, 2019) of the global C. tropicalis MLST database, and most genotypes and genetic clusters can colonize in various human body sites and cause infections.…”

“…The prevalence and drug resistance rates of C . tropicalis vary between and within geographical regions, and local epidemiological data are essential for management (Fernández‐Ruiz et al, 2015; Scordino et al, 2018; Tan et al, 2016; Wu et al, 2019). The molecular epidemiological study of C .…”

“…The molecular epidemiological study of C . tropicalis can explore the epidemic genotype, potential route of transmission, the genetic background of drug‐resistant strains, biological niches, and population structure (Wu, Guo, et al, 2017; Wu et al, 2019; Zuza‐Alves et al, 2017). At present, several genetic typing methods have been used to study the molecular epidemiology of C .…”

“…The prevalence and drug resistance rates of C. tropicalis vary between and within geographical regions, and local epidemiological data are essential for management (Fernández-Ruiz et al, 2015;Scordino et al, 2018;Tan et al, 2016;Wu et al, 2019). The molecular epidemiological study of C. tropicalis can explore the epidemic genotype, potential route of transmission, the genetic background of drug-resistant strains, biological niches, and population structure (Wu, Guo, et al, 2017;Wu et al, 2019;Zuza-Alves et al, 2017). At present, several genetic typing methods have been used to study the molecular epidemiology of C. tropicalis.…”