AUTHOR=Rouhi Faezeh , Soltani Sajedeh , Sadeghi Somayeh , Nasri Elahe , Hosseini Mahnaz , Ghafel Safiyeh , Aboutalebian Shima , Fakhim Hamed , Mirhendi Hossein 

TITLE=Yeast species in the respiratory samples of COVID-19 patients; molecular tracking of Candida auris

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=14

YEAR=2024

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2024.1295841

DOI=10.3389/fcimb.2024.1295841

ISSN=2235-2988

ABSTRACT=<sec><title>Introduction</title><p>Although the existence of <italic>Candida</italic> species in the respiratory tract is often considered commensal, it is crucial to recognize the significance of <italic>Candida</italic> colonization in immunocompromised or COVID-19 patients. The emergence of <italic>Candida auris</italic> as an emerging pathogen further emphasizes the importance of monitoring yeast infection/colonization, particularly in COVID-19 patients.</p></sec><sec><title>Methods</title><p>In this study, respiratory samples mainly from COVID-19 patients, primarily those suspected of having a fungal infection, were cultured on Sabouraud dextrose agar plates and the yeast colonies were identified using a two-step multiplex PCR method. The samples suspected of <italic>C. auris</italic> underwent specific nested PCR followed by sequence analysis.</p></sec><sec><title>Results</title><p>A total of 199 respiratory samples were collected from 73 women and 126 men, ranging in age from 1.6 to 88 years. Among the patients, 141 had COVID-19, 32 had cancer, 5 were hospitalized in ICU, 2 had chronic obstructive pulmonary disease)COPD(, and others were patients with combination diseases. From these samples, a total of 334 yeast strains were identified. <italic>C. albicans</italic> (n=132, 39.52%) was the most common species, followed by <italic>C. tropicalis</italic> (n=67, 20%), <italic>C. glabrata</italic> (n=56, 16.76%), <italic>C. krusei</italic> (n=18, 5.4%), <italic>C. parapsilosis</italic> (n=17, 5.08%), <italic>Saccharomyces cerevisiae</italic> (n=10, 3%), <italic>C. kefyr</italic> (n=9, 2.6%), <italic>C. dubliniensis</italic> (n=7, 2.1%), <italic>C. lusitaniae</italic> (n=5, 1.5%), <italic>C. auris</italic> (n=3, 0.9%), <italic>C. guilliermondii</italic> (n=2, 0.6%), <italic>C. rugosa</italic> (n=1, 0.3%), <italic>C. intermedia</italic> (n=1, 0.3%), and <italic>Trichosporon</italic> spp. (n=1, 0.3%). <italic>C. auris</italic> was detected in a patient in ICU and two COVID-19 patients. While its presence was confirmed through sequence analysis, our extensive efforts to isolate <italic>C. auris</italic> were unsuccessful.</p></sec><sec><title>Conclusion</title><p>While <italic>C. albicans</italic> colonization remains prevalent, our study found no evidence of <italic>Candida</italic> lung infection. Since the role of <italic>Candida</italic> colonization in airway secretions remains ambiguous due to limited research, further studies are imperative to shed light on this matter.</p></sec>