Distribution of gram-negative bacteria in lower respiratory tract infections and their susceptibility patterns to beta-lactam antibiotics during the COVID-19 pandemic

Abstract

Background and Objectives: Inappropriate antibiotic use can lead to resistance, particularly in Gram-negative bacteria. The aimd of this study was to identify the distribution of Gram-negative bacteria responsible for lower respiratory tract infections and to assess their susceptibility profiles to beta-lactam antibiotics in the periods before and during the COVID-19 pandemic.

Materials and Methods: This retrospective cross-sectional study utilized secondary data from WHONET 2022, drawing on a database of Gram-negative bacteria isolated from lower respiratory tract specimens processed at the Clinical Microbiology Laboratory, Faculty of Medicine, Universitas Indonesia, during the period of 2018-2021. Susceptibility to ampicillin-sulbac- tam, ceftazidime, cefepime, meropenem, and piperacillin-tazobactam was assessed. Comparisons between the pre-pandemic and pandemic periods were conducted using the chi-square test.

Results: A total of 569 samples were analyzed, comprising 383 samples from the pre-pandemic period (2018-2019) and 186 samples from the COVID-19 pandemic period (2020-2021). Twenty-nine Gram-negative bacterial species were identified before the pandemic, compared with 19 species during the COVID-19 pandemic. Klebsiella pneumoniae emerged as the most common pathogen, with a prevalance of 30.29% before and 27.96% during the COVID-19 pandemic. Statistical analy- sis revealed significant differences in the resistance patterns of Acinetobacter baumannii to cefepime (p= 0.036), ceftazidime (p= 0.018), and piperacillin-tazobactam (p= 0.002). Conversely, no significant differences were observed for K. pneumoniae and Pseudomonas aeruginosa (p > 0.05).

Conclusion: K. Pneumoniae remains the predominant Gram-negative pathogen causing lower respiratory tract infections, whereas A. baumannii shows an increased disease burden and resistance during the COVID-19 pandemic. This underscores the importance of continuous surveillance of antimicrobial resistance.