Surveillance of multidrug-resistant Escherichia coli in hospital wastewater and adjacent community water in Dhaka City, Bangladesh: A pilot cross-sectional study

Background: The spread of multidrug-resistant (MDR) Escherichia coli poses a serious and escalating public health concern, especially in low-resource countries where wastewater treatment systems are inadequate. Hospital effluents serve as major reservoirs of resistant pathogens, which may transfer into surrounding community water. Aim:This pilot surveillance study aimed to investigate the occurrence and transfer potential of MDR E. coli between hospital wastewater and adjacent community water sources in Dhaka City, Bangladesh. Methods: Eighteen water samples were collected between November 2022 and January 2023 from three major hospitals (oncology, pediatrics, and infectious disease) and their adjacent residential areas. Isolation was carried out on HiCrome KPC agar, and bacterial identity was confirmed by 16S rRNA PCR. Antimicrobial susceptibility testing was performed against commonly used antibiotics. Results: PCR confirmed 11 E. coli isolates, including 9 from hospital wastewater and 2 from community water. Hospital isolates demonstrated high resistance rates against ampicillin (88.8%), tetracycline (66.6%), and third-generation cephalosporins (55.5%). Alarmingly, 44.4% of hospital isolates were carbapenem-resistant, indicating potential treatment failure with last-line antibiotics. Overall, 81.8% of all isolates displayed multidrug resistance. Conclusion: This proof-of-concept study provides the first evidence of MDR E. coli dissemination from hospital wastewater into community water reservoirs in Dhaka. The findings highlight an urgent need for robust wastewater management and systematic environmental surveillance to curb the spread of antimicrobial resistance.