AUTHOR=Aboualigalehdari Elham , Tahmasebi Birgani Maryam , Fatahinia Mahnaz , Hosseinzadeh Mehran 

TITLE=Transcription Factors of CAT1, EFG1, and BCR1 Are Effective in Persister Cells of Candida albicans-Associated HIV-Positive and Chemotherapy Patients

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.651221

DOI=10.3389/fmicb.2021.651221

ISSN=1664-302X

ABSTRACT=<sec><title>Background</title><p>Biofilm is an accumulation of cells, which are formed on mucosal surfaces of the host as well as on medical devices. The inherent resistance of <italic>Candida</italic> strains producing biofilms to antimicrobial agents is an important and key feature for biofilm growth, which can lead to treatment failure. This resistance is due to the regulatory increase of the output pumps, the presence of extracellular matrix, and the existence of persister cells. Persister cells are phenotypic variants that have MICs similar to antibiotic-sensitive populations and are able to tolerate high doses of antibiotics. The current study investigated the possible role of <italic>EFG1, BCR1</italic>, and <italic>CAT1</italic> in the establishment or maintenance of persister cells in <italic>Candida albicans</italic> strains that produce biofilms.</p></sec><sec><title>Methods</title><p>After identifying <italic>Candida</italic> isolates by molecular methods, <italic>C. albicans</italic> isolates were confirmed by sequencing. Isolation of persister cells and determination of their MIC were performed by microdilution method. Then, RNA extraction and cDNA synthesis were performed from 60 <italic>C. albicans</italic> isolates under promoting and inducing conditions. Afterward, the mean expression of <italic>BCR1, EFG1</italic>, and <italic>CAT1</italic> genes in both persister and non-persister groups was calculated using real-time qPCR. Phylogeny tree of persister and non-persister group isolates was drawn using ITS fragment.</p></sec><sec><title>Results</title><p>A total of 77 persister isolates were taken from the oral cavity of HIV patients as well as from patients undergoing chemotherapy. Biofilm intensity in persister isolates separated from HIV-infected patients was different from the non-persister group. The mean fold change of <italic>BCR1</italic> (10.73), <italic>CAT1</italic> (15.34), and <italic>EFG1</italic> (2.41) genes in persister isolates was significantly higher than these genes in isolates without persister.</p></sec><sec><title>Conclusion</title><p>It can be concluded that the most important factor in the production of persister cells is biofilm binding and production, not biofilm development or mature biofilm production, which was found in the expression of <italic>BCR1</italic> gene without change in the expression of <italic>EFG1</italic> gene in the persister group. Also, catalase plays an essential role in the production of persister in <italic>C. albicans</italic> biofilm producers with ROS detoxification.</p></sec>