AUTHOR=Tian Sufei , Bing Jian , Chu Yunzhuo , Li Hailong , Wang Qihui , Cheng Shitong , Chen Jingjing , Shang Hong 

TITLE=Phenotypic and genetic features of a novel clinically isolated rough morphotype Candida auris

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1174878

DOI=10.3389/fmicb.2023.1174878

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p><italic>Candida auris</italic> is a newly emerging pathogenic fungus of global concern and has been defined by the World Health Organization (WHO) as a member of the critical group of the most health-threatening fungi.</p></sec><sec><title>Methods</title><p>This study reveals and reports for the first time that a rough morphotype <italic>C. auris</italic> strain causes urinary tract infections in non-intensive care unit (ICU) inpatients. Furthermore, the morphology, the scanning electronmicroscopy (SEM), Whole-genome resequencing and RNA sequencing of <italic>C. auris</italic> possessing rough morphotype colonies compared to their smooth morphotype counterparts.</p></sec><sec><title>Results</title><p>The newly identified phenotypic variation of <italic>C. auris</italic> appears round, convex, dry, and burr-like with a rough texture. SEM shows that rough type <italic>C. auris</italic> has a rough and uneven colony surface with radial wrinkles and irregular spore arrangement. Cells of the rough morphotype <italic>C. auris</italic> naturally aggregate into clusters with tight connections in the liquid, and it seems that the cell division is incomplete. A genome-wide analysis of the rough type <italic>C. auris</italic> confirmed its genetic association with the smooth type of <italic>C. auris</italic> prevalent in China (Shenyang) two years ago; however, single nucleotide polymorphism (SNP) mutations of five genes (<italic>ACE2</italic>, <italic>IFF6</italic>, <italic>RER2</italic>, <italic>UTP20</italic>, and <italic>CaO19.5847</italic>) were identified more recently. RNA-seq revealed <italic>IFF2/HYR3</italic>, <italic>DAL5</italic>, <italic>PSA31</italic>, and <italic>SIT1</italic> were notably up-regulated, while multiple cell wall-associated genes (<italic>ALS1</italic>, <italic>MNN1</italic>, <italic>PUL1</italic>, <italic>DSE1</italic>, <italic>SCW11</italic>, <italic>PGA38</italic>, <italic>RBE1</italic>, <italic>FGR41</italic>, <italic>BGLI</italic>, <italic>GIT3</italic>, <italic>CEP3</italic>, and <italic>SAP2</italic>) were consistently down-regulated in rough morphotype <italic>C. auris</italic>.</p></sec><sec><title>Discussion</title><p>The rough phenotypic variation of <italic>C. auris</italic> is likely to be related to the structural and functional changes in cell wall proteins. This novel rough morphotype <italic>C. auris</italic> will provide a basis for further studies concerning the evolutionary characteristics of <italic>C. auris</italic>.</p></sec>