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=10

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=<p><italic>Candida albicans</italic> is commensal in human microbiota and is known to be the commonest opportunistic pathogen, having variable clinical outcomes that can lead to up to 60% mortality. Such wide clinical behaviour can be attributed to its phenotypical plasticity and high genetic diversity. This study characterised 10 Colombian clinical isolates which had already been identified as <italic>C. albicans</italic> 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 <italic>C. africana</italic> and <italic>C. albicans</italic>. This study was aimed at evaluating atypical isolates’ pathogenic capability in the <italic>Galleria mellonella</italic> model; susceptibility profiles were determined and MLST was used for molecular characterisation. Cluster analysis, enabling unbiased bootstrap to classify the isolates and establish their cluster membership and e-BURST, was used for establishing clonal complexes (CC). Both approaches involved using representative MLST data from the 18 traditional <italic>C. albicans</italic> clades, as well as <italic>C. albicans</italic>-associated and minor species. Ten 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 represented 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 the isolates studied here was demonstrated by the contrast between phenotypical traits (<italic>C. africana</italic>-like), molecular markers (<italic>C. albicans</italic>-like), virulence, and antifungal resistance, highlighting the widely described genetic plasticity for this genus. Our results showed that the atypical isolates forming well-differentiated groups belonged to <italic>C. albicans</italic>. Our findings could contribute towards developing molecular epidemiology approaches for managing hospital-acquired infection.</p>