Mass bathing events in River Kshipra, Central India- influence on the water quality and the antibiotic susceptibility pattern of commensal E.coli.

Background: Antibiotic resistance is one of the major global health emergencies. One potential source of dissemination of resistant bacteria is mass gatherings, e.g. mass bathing events. We evaluated the physicochemical parameters of water quality and the antibiotic resistance pattern in commensal Escherichia coli from river-water and river-sediment in pre-, during- and post-mass bathing events in river Kshipra, Central India.

Method/design: Water and sediment samples were collected from three selected points during eight mass bathing events during 2014-2016. Water quality parameters (physical, chemical and microbiological) were analyzed using standard methods. In river water and sediment samples, antibiotic susceptibility patterns of isolated E. coli to 17 antibiotics were tested.

Results: pH, turbidity and dissolved oxygen were significantly lower and total dissolved solid, free carbon dioxide were higher during mass bathing, whilst TSS, BOD and COD were lowest in pre-bathing and highest in post-bathing period. E.coli with multi drug resistance (MDR) or extended spectrum beta-lactamase (ESBL) production were between 9-44% and 6-24%, respectively in river-water as well as river-sediment. Total coliform count/ml and E. coli count were higher during-and post-bathing in river water than in pre-bathing period. Thus, the percentage of resistance was significantly higher during and post-bathing period (p<.05) than in pre-bathing. Colony forming unit (CFU)/ml in river-sediment was much higher than in river-water. Percentage of resistance was significantly higher in river-water (p<.05) than in river-sediment.

Conclusions: Antibiotic resistance in E.coli isolated from the Kshipra River showed significant variation during mass bathing events. Guidelines and regulatory standards are needed to control environmental dissemination of resistant bacteria.