Features of the Etiology of Pneumonia Associated With the Sars-Cov-2 Virus in the Primorsky Territory

AIM: comparative analysis of the etiological structure of pneumonia in patients with coronavirus infection caused by SARS-CoV-2 in the Primorsky Territory and assessment of antibiotic resistance of microflora. METHODS: A retrospective cohort study was conducted of 6491 medical records of patients with confirmed coronavirus infection who were hospitalized between 2021 and 2023. Bacteriological analysis of the biomaterial was performed using differential diagnostic media and identification of isolated pathogens with determination of antibiotic resistance using the BD Phoenix™ automated bacteriological analyzer. RESULTS: In 2021, pneumonias were predominantly of viral etiology, with a microbial agent detected in only 1/3 of cases. Subsequently, a feature of pneumonia in patients with laboratory-confirmed COVID-19 was a high frequency of mixed infections of bacterial etiology, as well as an increase in the proportion of opportunistic flora in the sputum microbiome (unicellular fungi of the genus Candida, Mycoplasma bacteria) with an increase of more than 6 times by 2023. The isolated bacteria were etiologically significant and belong to the ESKAPE group, in most cases they were obtained in monoculture or together with yeast fungi. Until 2022, gram-positive flora prevailed, and in 2023 its ratio with gram-negative was in equal proportions. The number of methicillin-resistant Staphylococcus aureus reached 52.7%, and resistant to most antibacterial drugs - 77.2%. Gram-positive microorganisms were resistant to penicillin and fluoroquinolone antibiotics, and gram-negative ones were resistant to third-generation cephalosporins, fluoroquinolones and carbapenems. CONCLUSION: In 2021, pneumonia in sputum was mainly Gram-positive flora, while by 2023 there was an increase in the number of Gram-negative, as well as an increase in opportunistic flora. Antibiotic resistance of the most common gram-positive microorganisms is most pronounced in relation to drugs related to penicillins and fluoroquinolones, and in gram-negative ones to 3rd generation cephalosporins, fluoroquinolones and carbopenems. Thus, the sputum microbiome in pneumonia in patients with coronavirus infection in the Primorsky Territory has its own characteristics, which should be taken into account when prescribing etiotropic therapy.