Deciphering Colonies of Phenotypic Switching-Derived Morphotypes of the Pathogenic Yeast Candida tropicalis

Cássia Milena de Souza; Alane Tatiana Pereira Moralez; Murilo Moreira Dos Santos; Mario Sérgio Mantovani; Luciana Furlaneto-Maia; Marcia Cristina Furlaneto

doi:10.1007/s11046-022-00663-4

Deciphering Colonies of Phenotypic Switching-Derived Morphotypes of the Pathogenic Yeast Candida tropicalis

Mycopathologia. 2022 Dec;187(5-6):509-516. doi: 10.1007/s11046-022-00663-4. Epub 2022 Sep 4.

Authors

Cássia Milena de Souza¹, Alane Tatiana Pereira Moralez¹, Murilo Moreira Dos Santos¹, Mario Sérgio Mantovani², Luciana Furlaneto-Maia³, Marcia Cristina Furlaneto⁴

Affiliations

¹ Department of Microbiology, Center of Biological Sciences, Paraná State University of Londrina, Rodovia Celso Garcia Cid, Pr 445 Km 380, C.P. 6001, Londrina, Paraná, 86051990, Brazil.
² Department of General Biology, State University of Londrina, Londrina, Paraná, Brazil.
³ Technological Federal University of Paraná, Londrina, Paraná, Brazil.
⁴ Department of Microbiology, Center of Biological Sciences, Paraná State University of Londrina, Rodovia Celso Garcia Cid, Pr 445 Km 380, C.P. 6001, Londrina, Paraná, 86051990, Brazil. furlaneto@uel.br.

PMID: 36057915
DOI: 10.1007/s11046-022-00663-4

Abstract

Background: Phenotypic switching generates fungal colonies with altered morphology and allows pathogens to adapt to changing environments.

Objective: This study investigated the structure and genetic factors of switched morphotypes colonies in Candida tropicalis.

Methods: Morphotypes of C. tropicalis comprised the clinical strain 49.07 that exhibited smooth colony phenotype and switched (crepe and rough) morphotypes that showed colonies with marked structural variations, including wrinkled surface, depressions areas, and irregular edges (structured morphology). The morphotypes were analyzed for the presence and distribution of the extracellular matrix (ECM) at the ultrastructural level-SEM. The composition of the ECM and the percentage of hyphae in colonies were evaluated. The expression of EFG1 (Enhanced filamentous growth protein 1), WOR1 (White-opaque regulator 1), and BCR1 (Biofilm and cell wall regulator 1) in the morphotypes was measured by RT-qPCR.

Results: Colonies of the switched variants exhibited distinct arrangements of ECM compared to the smooth phenotype (clinical strain). In addition, rough variant colonies showed higher amounts of total carbohydrates and proteins in ECM (p < 0.05). Switched (crepe and rough) colonies exhibited a higher percentage of hyphae throughout their development (p < 0.05). The mRNA expression levels of EFG1, WOR1, and BCR1 in the rough morphotype were significantly higher than they were in the smooth morphotype. In addition, there was a positive correlation between the expression of these genes and filamentation (hyphae formation) of the rough morphotype (r² > 0.9472, p < 0.05).

Conclusion: Structural variations in switched morphotypes colonies of C. tropicalis seem to be associated with increased hyphae growth and the amount and distribution of ECM. Switched colonies have distinct expressions of the EFG1, WOR1, and BCR1 master regulators genes.

Keywords: Colony structure; Extracellular matrix; Hyphae; Phenotypic switching; Transcription factors.

MeSH terms

Biofilms
Candida tropicalis* / genetics
Extracellular Matrix
Hyphae* / genetics
Phenotype