Microbial Agents and Antimicrobial Resistance Patterns in Blood Cultures of Intensive Care Unit Patients: Pre- and Post-COVID-19 Pandemic Analysis

Microbial Agents and Antimicrobial Resistance Patterns in Blood Cultures During COVID-19

Abstract

Objective: This study aimed to identify the microbial agents isolated from blood cultures of intensive care unit (ICU) patients and their antibiotic resistance rates before and after the Coronavirus Disease 2019 (COVID-19) pandemic.
Methods: Blood culture samples from general ICU-1 and ICU-2, collected between 2018-2022, were retrospectively analyzed.
Results: Of the samples analyzed, 44.4% showed positive culture growth, 46.1% showed no growth, and 9.5% were determined to be skin contaminants. In both ICUs, coagulase-negative staphylococci were the most frequently isolated microorganisms, followed by Enterococcus species. Methicillin resistance in Staphylococcus aureus significantly decreased in ICU-1 after the pandemic but increased significantly in ICU-2. Resistance rates to vancomycin and teicoplanin in Enterococcus species significantly increased during the pandemic in both ICUs. No colistin resistance was detected in Escherichia coli, but colistin resistance rates significantly increased in other Gram-negative isolates during the pandemic, except for Pseudomonas aeruginosa in ICU-1. After the pandemic, Klebsiella pneumoniae in ICU-1 and Acinetobacter baumannii in ICU-2 showed the highest colistin resistance rates.
Conclusion: This study revealed that, during the pandemic, there was a shift in the distribution of isolated pathogens, accompanied by increased resistance rates even to last-resort antibiotics such as vancomycin and colistin.