Seasonal prevalence of antibiotic-resistant bacteria in the river Mula-Mutha, India.

The river Mula-Mutha in Pune District, India, is linked to a number of major drinking water sources in villages situated along its banks. This study assessed the seasonal variations in bacteriological water quality along the Mula-Mutha river using Thermotolerant Faecal Coliforms (TFC) as indicator bacteria for faecal contamination as per the WHO standard guidelines for drinking water. Eight points were chosen based on a survey carried out focusing on different sources of contamination which may influence water quality. Based on the survey of antibiotics used to treat routine diseases and ailments in villages, ceftazidime and ciprofloxacin were selected to screen and enumerate antibiotic-resistant (AR) TFC. The water samples were collected and analyzed along the Mula-Mutha riverbank in three seasons. The highest TFC load was recorded during the monsoon at all eight sampling points. The percentages of ciprofloxacin-resistant TFC among the TFC isolated in post-monsoon, pre-monsoon and monsoon were 21%, 2.3%, and 64%, to those resistant to ceftazidime 9%, 0.5%, and 36% and to the combination 38%, 0.7%, and 43%, respectively. Downstream from Manjari, at Khamgaontek, antibiotic-resistant TFC were detected in all three seasons though the number isolated was less. Still further downstream at Walki, the numbers decreased considerably. The findings highlighted the heavy load of AR TFC detected in the river Mula-Mutha at points adjoining Pune City. This was probably due to the release of domestic and hospital wastes from the city into the river.