AUTHOR=Rodríguez-Leguizamón Giovanni , Ceballos-Garzón Andrés , Suárez Carlos F. , Patarroyo Manuel A. , Parra-Giraldo Claudia M. 

TITLE=Robust, Comprehensive Molecular, and Phenotypical Characterisation of Atypical Candida albicans Clinical Isolates From Bogotá, Colombia

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=Volume 10 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2020.571147

DOI=10.3389/fcimb.2020.571147

ISSN=2235-2988

ABSTRACT=Candida albicans is commensal in human microbiota and is known to be the commonest opportunistic pathogen, with variable clinical outcomes that can lead to up to 60% mortality. Such wide clinical behaviour can be attributed to their phenotypical plasticity and high genetic diversity. This study characterised ten Colombian clinical isolates which had already been identified as C. albicans by molecular tests; however, previous bioinformatics analysis of protein mass spectra and phenotypical characteristics has shown that this group of isolates has atypical behaviour, sharing characteristics of both C. africana and C. albicans. This study was aimed at evaluating atypical isolates’ pathogenic capability in the Galleria mellonella model; susceptibility profiles were determined and MLST was used for molecular characterisation. Cluster analysis enabling unbiased bootstrap to classify the isolates and establishing their cluster membership and e-BURST was used to stablishing clonal complexes (CC). Both approaches involved using representative MLST data from the eighteen traditional C. albicans clades, as well as C. albicans-associated and minor species. 10 atypical isolates were distributed as follows: 6/10 (B71, B41, B60, R6, R41 and R282) were grouped into a statistically well-supported atypical cluster (AC) and constituted a differentiated CC 6. 2/10 of the isolates were clearly grouped in clade 1 and were concurrent in CC 4 (B80, B44). Another 2/10 atypical isolates were grouped in clade 10 and concurred in CC 7 (R425, R111); most atypical isolates were related to geographically distant isolates and some ended up representing new ST. Isolates B41 and R41 in the AC had greater virulence. Isolate B44 was fluconazole-resistant and was grouped in clade 1. The atypical nature of studied isolates was evidenced by the contrast between phenotypical traits (C. africana-like), molecular markers (C. albicans-like), virulence and antifungal resistance, showing the genetic plasticity widely described for this genus. Our results showed that the studied atypical isolates forming well-differentiated groups belonged to C. albicans. Our findings could contribute to develop molecular epidemiology approaches to manage hospital-acquired infections.