Detection and antimicrobial resistance profiling of nosocomial bacterial pathogens in two tertiary care hospitals of Dhaka, Bangladesh

Abstract

Nosocomial infections remain a significant global health burden, posing persistent challenges in hospital settings, including in Bangladesh. Prompt identification of causative agents and appropriate antimicrobial therapy are essential, as delayed or inadequate treatment increases patient morbidity and mortality. This study investigated the prevalence and antimicrobial resistance patterns of most ESKAPE pathogens- Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, —excluding Enterococcus faecium and Enterobacter species, known for high virulence and multidrug resistance in hospital-acquired infections worldwide. However, Escherichia coli was included in this study as it was one of the most prevalent bacteria found in the hospital environment. Environmental swabs were collected from high-touch surfaces, including bed rails, bed sheets, nursing tables, and saline stands, across ICU, NICU, and children’s wards of two tertiary hospitals in Dhaka. Samples were serially diluted, cultured on selective media, and presumptively identified by colony morphology, with confirmation via polymerase chain reaction (PCR) and gel electrophoresis. Antimicrobial susceptibility was assessed using the Kirby–Bauer disc diffusion method. From 22 samples, Klebsiella pneumoniae was most prevalent (36.6%), followed by Staphylococcus spp. and Escherichia coli (18.18%). Acinetobacter baumannii (13.64%), and Pseudomonas aeruginosa (9.1%) with the lowest amount of prevalence. High resistance was noted against Beta-lactams (41.18% – 64.71%) and macrolides (47.06%), while lower resistance was found against carbopenem. MDR rates were highest in Staphylococcus species and Escherichia coli (100%), followed by Klebsiella pneumoniae (75%), Pseudomonas aeruginosa (50%), and Acinetobacter baumannii (33.3%). These findings underscore the urgent need for continuous surveillance, stringent infection control, and rational antibiotic use to mitigate multidrug-resistant pathogens in hospital environments.