Yeast species in the respiratory samples of COVID-19 patients; molecular tracking of .

Introduction: Although the existence of species in the respiratory tract is often considered commensal, it is crucial to recognize the significance of colonization in immunocompromised or COVID-19 patients. The emergence of as an emerging pathogen further emphasizes the importance of monitoring yeast infection/colonization, particularly in COVID-19 patients.

Methods: 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 underwent specific nested PCR followed by sequence analysis.

Results: 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. (n=132, 39.52%) was the most common species, followed by (n=67, 20%), (n=56, 16.76%), (n=18, 5.4%), (n=17, 5.08%), (n=10, 3%), (n=9, 2.6%), (n=7, 2.1%), (n=5, 1.5%), (n=3, 0.9%), (n=2, 0.6%), (n=1, 0.3%), (n=1, 0.3%), and spp. (n=1, 0.3%). 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 were unsuccessful.

Conclusion: While colonization remains prevalent, our study found no evidence of lung infection. Since the role of colonization in airway secretions remains ambiguous due to limited research, further studies are imperative to shed light on this matter.