Determine phenotypical patterns of resistance to antibiotics in COVID-19 patients with associated bacterial infection: largest medical center in Iran.

Background and objectives: Antibacterial resistance (AMR) is a serious threat and major concern, especially in developing countries. Therefore, we aimed to determine phenotypical patterns of resistance to antibiotics in COVID-19 patients with associated bacterial infection in intensive care units.

Materials and methods: In this cross-sectional study, 6524 COVID-19 patients admitted for more than 48 h in the ICUs of Imam Khomeini Complex Hospital (IKCH) in Tehran from March 2020 to January 2022 were included in the study with initial diagnosis of COVID-19 (PCR test and chest imaging). Data were collected regarding severity of the illness, primary reason for ICU admission, presence of risk factors, presence of infection, length of ICU and hospital stay, microbial type, and antibiotic resistance. In this study, the pattern of antibiotic resistance was determined using the Kirby-Bauer disk diffusion method.

Results: In this study, 439 (37.5%) were ventilator-related events (VAEs), and 46% of all hospitalized patients had an underlying disease. The most common microorganisms in COVID-19 patients were carbapenem resistant Klebsiella pneumoniae (KPCs) (31.6%), Escherichia coli (E. coli) (15.8%), and Acinetobacter baumannii (A. baumannii) (15.7%), respectively. Prevalence of vancomycin-resistant enterococci (VRE) and KPCs were 88% and 82%, respectively.

Conclusion: A study on AMR surveillance is the need of the hour as it will help centers to generate local antibiograms that will further help formulate national data. It will guide doctors to choose the appropriate empiric treatment, and these studies will be the basis for establishing antimicrobial surveillance and monitoring and regulating of the use of antimicrobials.