Isolation, Identification, and Antibiotic Resistance of Common Pathogens in Hospital Drain Water from Dhaka and Surrounding Areas, Bangladesh

Abstract

The global rise of antimicrobial resistance has emerged as a pressing public health concern, particularly in developing countries, where untreated hospital effluents are a major contributor to environmental contamination. This study aimed to isolate, identify, and assess the antibiotic susceptibility patterns of the most prevalent organisms in hospital drain water from Dhaka city and its surrounding regions in Bangladesh. A total of nine wastewater samples were collected from a large reservoir adjacent to the populated hospitals. Standard microbiological techniques, including selective culturing on MacConkey and Eosin Methylene Blue agars, Gram staining, and a series of biochemical tests, were employed to identify the isolates.  Antimicrobial susceptibility testing was performed using a range of commonly used antibiotics. The findings revealed a high prevalence of Escherichia coli and Klebsiella spp.  Both organisms exhibited multidrug resistance (MDR) to several antibiotics, including ampicillin, amoxicillin, and nalidixic acid. Norfloxacin antibiotic was found to be more effective, 68% and 64% susceptible against Klebsiella spp. and Escherichia coli, respectively. Klebsiella spp. and Escherichia coli isolates were found 100% resistant to Vancomycin and Ampicillin. The resistance patterns suggest the presence of extended-spectrum β-lactamase (ESBL)-producing strains, posing a potential threat to community health. The results emphasize the alarming role of untreated hospital wastewater as a reservoir and vector for MDR pathogens, which can contaminate the broader environment, including water bodies used for irrigation and household consumption.