P494 Comparison of Candida
colonization in intensive care unit patients with and without COVID-19: First prospective cohort study from Turkey
Authors: Küçükkaya İlvana Çaklovica , Orhun Günseli , Çağatay Arif Atahan , Kalaycı Sadık , Esen Figen , Şahin Fikrettin , Ağaçfidan Ali , Erturan Zayre 
Published: September 2022

Abstract

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM

Objectives
Candida species, as the main component of human mycobiome, are the most common cause of fungal infections in intensive care units (ICU). ICU patients with COVID-19 are more prone to fungal infections, due to various causes like mechanical ventilation, use of steroids, or long-term hospitalization. There is yet no extended prospective study examining Candida colonization rates, epidemiology of species, and predisposing factors in this population. This is the first prospective cohort study comparing the time-varying colonization features of Candida species in ICU patients with and without COVID-19.

Methods
This study was performed between March 2021-December 2021 in ICUs of Istanbul University, Istanbul Faculty of Medicine, Department of Anesthesiology and Reanimation. COVID-19 and non-COVID-19 ICU patients who were ≥ 18 years and expected to stay in the ICU for at least 7 days were included in the study.
Samples were taken at certain time intervals from different body parts of the patients [mouth, skin (axilla), rectal, and urine] (Table 1) and evaluated at Istanbul University, Istanbul Faculty of Medicine, Department of Medical Microbiology, Mycology Laboratory. All specimens were inoculated on CHROMagar Candida media (CHROMagar Candida, France) to detect mixed growth and CHROMagar Candida Plus media (CHROMagar Candida Plus, France) to avoid missing Candida auris.
Cultures were incubated at 35-37⁰C for 48 h and phenotypically different colonies on primary media were subcultured on corn meal-tween-80 agar for determining their morphology. All strains were identified to the species level using MALDI-TOF MS (Version 4.1.80; Biotyper Bruker) in Yeditepe University, Faculty of Engineering, Genetics and Bioengineering Department. Patient groups were compared statistically in terms of isolated Candida species and distribution according to regions.

Results
The study consisted of 122 ICU patients including 62 COVID-19 (25 female; 37 male; mean age:63.29 years) and 60 non-COVID-19 (24 female; 36 male; mean age:63.9 years).
A total of 1464 samples (756 COVID-19 and 708 non-COVID-19 patients) were taken (Table 1) and fungi grew in 340 (23.2%) samples. Mixed growth was observed in 108 cultures; was more frequently in COVID-19 patients (P &lt; .05), and significantly higher in oral specimens (P &lt; .05).
Out of a total of 471 strains that were obtained from fungal cultures, C. albicans (42.25%) and C. glabrata (24.2%) were most frequently isolated. Candida auris was not observed in this period (Table 2).
Patients with COVID-19 were found more frequently colonized in oral (P &lt; .001), rectal (P &lt; .05) regions and urine (P &lt; .001) compared with non-COVID-19 patients. There was no growth in the axillary region in any of the patients.
Non-albicans Candida strains were found significantly more frequent in patients with COVID-19 in oral (P &lt; .001) and rectal regions (P &lt; .05).

Conclusion
In this study, we found significantly higher oral, rectal, and urine Candida colonization rates in COVID-19 ICU patients compared with non-COVID-19 individuals. Increased oral Candida colonization can be the result of insufficient oral care application to these patients in the ICUs due to infection control anxiety, and also mechanical ventilation.
Because non-albicans Candida strains were found significantly more frequent in COVID-19 patients, intrinsically resistant isolates should be kept in mind before administering antifungals.
The high mixed growth rate detected in all individuals and especially in COVID-19 patients will affect the antifungal therapy and therefore emphasized the importance of using chromogenic media for routine evaluation.