Genotypic and phenotypic portrait of Candida albicans clinical isolates colonizing the airways of patients with cystic fibrosis

• Published in: Access microbiology Vol. 3; no. 12
• Main Authors: Gnaien, Mayssa, Kallel, Aicha, Khalsi, Fatma, Hamouda, Samia, Smaoui, Hanen, Khemiri, Monia, Hadj Fredj, Sondes, Messaoud, Taieb, Boussetta, Khadija, Kallel, Kalthoum, d'Enfert, Christophe, Bougnoux, Marie-Elisabeth, Mardassi, Helmi, Znaidi, Sadri
• Format: Journal Article
• Language: English
• Published: 17-12-2021
• ISSN: 2516-8290; 2516-8290
• DOI: 10.1099/acmi.cc2021.po0015

Candida albicans
colonizes the respiratory tract of patients with Cystic Fibrosis (CF). It competes with CF-associated pathogens, such as
Pseudomonas aeruginosa
and
Staphylococcus aureus
, and contributes to disease severity. We serially recovered 160
C. albicans
clinical isolates over a period of 30 months from the sputum of 23 pediatric and 2 adult antifungal-naive CF patients at Children’s Hospital Tunis and characterized the genotype and phenotype of a subset of strains using multilocus sequence typing (MLST) and growth assays on multiple stress-, filamentous growth- and biofilm-inducing media. Out of 16 patients regularly sampled for at least 9 months, 8 and 4 were chronically and transiently colonized with
C. albicans
, respectively. MLST analyses of 56 strains originating from 15 patients indicated that each patient was colonized with a single strain, while 8 patients (53%) carried isolates from clade 4 known to be enriched with strains from Middle East-Africa. A subset of these isolates with the same sequence type and colonizing 3 unrelated patients displayed altered susceptibility to cell wall-perturbing agents, suggesting changes in cell wall structure/function during growth in the CF lung. We also observed differential ability to filament and/or form biofilms in a set of identical isolates from clade 10 sampled over a period of 9 months in a pediatric CF patient, suggesting alterations in phenotypes associated with virulence. Our findings will rely on future whole-genome sequencing analyses to identify polymorphisms that could explain the emergence of new traits in
C. albicans
strains thriving in the CF host environment.