Changing Trends in Bacteriological Profile of Respiratory Isolates during Pre-COVID-19, COVID-19 and Post-COVID-19 Era: A Cross-sectional Study

Introduction: The Coronavirus Disease-2019 (COVID-19) pandemic has exacerbated the global challenge of antibiotic resistance, particularly among respiratory pathogens. Findings from previous research highlight the urgent need to address antibiotic resistance in respiratory isolates during the COVID19 era. Aim: To investigate the changing trends in bacterial isolates, their prevalence, and antibiotic resistance patterns in respiratory samples from ward and Intensive Care Unit (ICU) settings during the pre-COVID-19 (2019), COVID-19 (2020), and post-COVID19 (2022) periods. Materials and Methods: A cross-sectional study was conducted in the Department of Microbiology, Himalayan Institute of Medical Sciences, Swami Rama Himalayan University, Dehradun, Uttarakhand, India. The study covered a three-year period from January 2019 to December 2022, excluding the year 2021. Respiratory samples such as Endotracheal Aspirates (ETA), Bronchoalveolar Lavage (BAL), and sputum that were culture positive were included for bacterial isolation and analysis of antibiotic resistance patterns. Data were collected from both ward and ICU patients, and statistical comparisons across the three study periods were performed using the Chi-square test to calculate p-values. Results: A total of 830, 520, and 695 culture-positive respiratory isolates were analysed in 2019, 2020, and 2022, respectively. In the ICU, Acinetobacter spp. showed a significant increase from 26.49% in 2019 to 51.16% in 2020, followed by a marginal decline to 48.14% in 2022 (p-value <0.001). Klebsiella spp. exhibited a gradual rise in prevalence, while Pseudomonas aeruginosa initially decreased during the COVID-19 period but rebounded post-COVID-19. Antibiotic resistance patterns revealed a significant increase in resistance to colistin, imipenem, piperacillin-tazobactam, and tigecycline, particularly among Klebsiella spp. and Acinetobacter spp. in ICU settings. Conclusion: The study highlights a concerning rise in antibiotic resistance among respiratory pathogens during the COVID19 and post-COVID-19 periods, particularly in ICU settings. These findings emphasise the need for stringent antimicrobial stewardship, strengthened infection control measures, and continuous surveillance of resistance patterns to mitigate the spread of Multidrug-Resistant (MDR) bacteria.