Secondary bacterial infections of the respiratory tract in COVID-19 patients.

Introduction: Secondary Bacterial Infections (SBIs) of the respiratory system are one of the biggest medical concerns in patients undergoing hospitalization with a diagnosis of COVID-19. This study aims to provide relevant data for the initiation of appropriate empirical treatment after examining the etiology and antimicrobial resistance of SBIs in COVID-19 patients under care in the Intensive Care Units (ICUs) in the largest pandemic hospital of our country.

Methodology: Between March 16, 2020 and December 31, 2021, 56,993 COVID patients were hospitalized, of which 7684 were admitted to ICUs. A total of 1513 patients diagnosed with SBIs have been included in this study. During the course of the study, demographic data, clinical course, etiology and antimicrobial resistance data of all patients were collected.

Results: The most common causative agents of SBIs were inferred as Acinetobacter baumanii (35.1%), Staphylococcus aureus (15.2%), Klebsiella pneumoniae (12.3%) and Pseudomonas aeruginosa (10.4%). The isolation rates of carbapenem-resistant and colistin-resistant A. baumannii, K. pneumoniae and P. aeruginosa were 83.7%; 42.7%, 79.2%, and 5.6%, 42.7%, 1.7%, respectively. Acinetobacter pittii clustering was seen in one of the ICUs in the hospital. Multidrug resistant 92 (5.4%) Corynebacterium striatum isolates were also found as a causative agent with increasing frequency during the study period.

Conclusions: SBI of the respiratory system is one of the major complications in patients hospitalized with COVID-19. The antimicrobial resistance rates of the isolated bacteria are generally high, which indicates that more accurate use of antibacterial agents is necessary for SBIs in patients hospitalized with COVID-19 diagnosis.