Colonization and azole resistance of oropharyngeal <i>Candida</i> fungi in intensive care patients with COVID-19

Abstract

Patients with COVID-19 are susceptible to developing oropharyngeal candidiasis and invasive candidiasis. Invasive fungal infections can complicate the clinical course of COVID-19 and are associated with a substantially increased mortality. An important reason for the successful treatment of candidiasis is to determine the sensitivity of clinical fungal isolates to antimycotics. A microbiological study of oropharyngeal swabs was performed in 54 patients aged 33 to 94 years (mean age 67.4 years) with severe and extremely severe COVID-19, who were treated in the intensive care unit at the height of clinical manifestations. Most patients (95%) had comorbidities: hypertension (68.5%), diabetes mellitus (24%), coronary artery disease (22.2%), chronic heart failure (38.9%), obesity (23.8%), cardiac arrhythmias (20.4%), chronic cerebral ischemia (56.1%), varicose veins of the lower extremities (5.5%), chronic kidney disease (20.4%), liver cirrhosis (5.5%), HIV infection (5.5%). A comparative analysis of oropharyngeal microbial biocenosis showed differences in the frequency of occurrence of opportunistic microbial species, as well as in the number of members in microbial associations. Polyspecific fungal-bacterial associations were more common and dominated polyspecific bacterial associations. According to the results, a high frequency of oropharyngeal colonization in patients with severe COVID-19 by strains of fungi of the genus Candida was established. The vast majority of strains of fungi of the genus Candida (85.2%) were resistant to antimycotics of the azole group. A high frequency (85.2%) of oropharyngeal colonization in resuscitation patients with azole-resistant strains of fungi of the genus Candida was revealed. C. albicans dominated among Candida. C. albicans was isolated in 37 (68.5%) patients, C. pararapsilosis in 6 (11.1%), C. tropicalis in 3 (5.5%), C. krusei in 2 (3.7%)%), C. kefyr in 1 (1.9%), C. glabrata in 1 (1.9%) patient. In 11 (20.4%) patients, associations of C. albicans and other Candida species were identified. The level of fungi in the material was etiologically significant ( 104105 CFU/tamp.) in 80% of patients. The vast majority of strains (more than 70%) were resistant to fluconazole and voriconazole, which should be taken into account when prescribing candidiasis therapy in patients with COVID-19. The MIC for fluconazole against C. albicans strains was 1024 g/ml for 4 isolates, 512 g/ml for 7 isolates, and 128 g/ml for 15 isolates. The maximum MIC values for voriconazole against C. albicans was 256 g/ml.