Prevalence of carbapenem-resistant Escherichia coli in the drinking water system in Dhaka

Abstract

"Water pollution could cause serious health hazards and Dhaka, Bangladesh is one of those heavily populated cities that are considered harmful effects related to health. This research evaluated the microbial quality of water across 11 zones of Dhaka with specific focus on detection of Escherichia coli and its antibiotic resistance capabilities including that of carbapenems, antibiotics that are now a last option in treating severe infections associated with multidrug-resistant species of Enterobacteriaceae. The emerging incidence of carbapenem resistant isolates has critically reduced the options of treatment, which has now become a major public health challenge. A total of 200 water samples; tap, boiled and filtered; have been collected over the period October, 2023-April, 2024. Of the 410 bacterial isolates obtained, 103 were identified as E. coli. April had the highest average E. coli count in tap water at 50%. In contrast, January recorded the lowest average count for tap water at 3.3%. Overall, tap water consistently showed higher contamination levels than boiled and filtered water across the months. For example, in April, tap water had an average of 50%, while boiled water only had 13% and filter water was 19%. This trend indicates that tap water is generally more contaminated than the other types. Moreover, since all media contained meropenem with ZnSO4 and E. coli still exhibited growth, the season-wise resistance pattern was found to be 91% in summer, 75% in fall, and 41% in spring. This indicates that the isolates show the highest resistance pattern to meropenem during the summer season. Antibiotic susceptibility testing revealed that all E. coli were found 100% resistant to Ampicillin and Amoxyclav, while 91.43% were resistant to Meropenem. In contrast, the isolates showed notable sensitivity to Ceftazidime (94.29%) and Tetracycline (82.86%). PCR analysis of carbapenemase genes, blaNDM-1 and blaOXA-2, was done in 35 E. coli isolates. The results provide critical evidence of multidrug-resistant E. coli presence in the water system of Dhaka which highlights a need for increased water treatment systems, strict regulations on antibiotic campaigns, as well as a general public health program to control the spread of antimicrobial resistance. "