Comparative study of multidrug-resistant bacteria (MDRB) isolated from patients in different wards of a hospital during the post-COVID-19 period

Antibacterial resistance (ABR) remains a global health threat in the 21 st century. This study aimed to examine the prevalence and distribution of multidrug-resistant bacteria (MDRB) isolated from patients in a tertiary care hospital during (2021) and post-COVID-19 (2022 and 2023) pandemic years. In the study, 100 patients were involved, with 85 % successfully discharged (p-value = <0.00001), and 5 % deceased (p-value = <0.00001). Microbiological and antibiotic susceptibility testing was performed on patient samples to determine MDRB and assess their resistance profiles. The outcomes exhibited an increase in MDRB prevalence in 2022 (standard error, SE, ± 0.0351 to ± 0.0936) compared to 2021 (SE ± 0.0380 to ± 0.0654) and 2023 (SE ± 0 to ± 0.1158). Gammaproteobacteria was predominant across the recovered samples. Klebsiella pneumoniae (40 %), Escherichia coli (28 %), Citrobacter sp. (19 %), Acinetobacter sp. (7 %), and Pseudomonas aeruginosa (6 %) were recognized as the predominant populations. The Shapiro-Wilk test for normality varied from 0.800 to 0.888 ( p-value = <0.081–0.351), while the Anderson-Darling test ranged from 0.343 to 0.511 (p-value = <0.098–0.315). These MDRB exhibited Shannon and Simpson index values ranging from 1.138 to 1.508 and 0.643–0.775, respectively, with evenness values from 0.780 to 1.042, indicating microbial diversity in the patient samples. In antibiotic susceptibility testing, Acinetobacter sp. Citrobacter sp., Pseudomonas aeruginosa , Escherichia coli , and Klebsiella pneumoniae showed 100 % resistance to 23, 15, 14, 13, and 11 antibiotics, respectively. Further, compared to prior reports (de Souza et al., 2023, p-value = 0.00001, and Ruegsegger et al., 2022, p-value = <0.0061), the percentages of MDRB, i.e. Klebsiella pneumoniae (40 %), Escherichia coli (28 %), and Citrobacter sp. (19 %), were significantly higher ( p-value = <0.00001) in this study. Overall, the MDRB distribution changed in prevalence across different years (2021 – 2023, during and post-COVID-19 pandemic) and medical conditions. Despite the high antibiotic resistance, the fatality rate in this study was lower than in other available reports, suggesting that effective recovery is possible with rapid and tailored treatment. These outcomes indicate the requirement for enhanced surveillance, monitoring, and targeted treatment strategies to manage ABR effectively. • Results revealed high antibacterial resistance post-COVID-19. • Males showed higher GNB (MDR) than females and children. • Higher dominancy & lower fatality of MDR patients compared to prior studies.