Seasonal variation in survival and antibiotic resistance among various bacterial populations in a tropical river

Abstract

Seasonal variations in bacterial populations and their antibiotic sensitivity were surveyed in the water of the river Gomati at Lucknow. Most of the bacteria showed an increase in their densities in sewage-contaminated downstream of the river during summer. In contrast, Aeromonas sp. count was found to be higher in upstream during winter. Vibrio cholerae non-01 was substantially found in downstream only. More than half of the bacterial isolates exhibited antibiotic resistance. The maximum resistance was shown by the winter isolates (36%), particularly from downstream (77.7%). Among the resistant isolates, resistance for ampicillin was predominant (42%), followed by tetracycline (40%). Single and multiple antibiotic resistances were the highest among 32% and 47% of aeromonads, respectively. The double resistance was exhibited to be maximum by the vibrio non-01 isolates. Disposal of municipal sewage with fecal wastes seems to be mainly responsible for deterioration of water quality along with increased population of pathogenic and antibiotic resistant bacteria in river. © 1993, Applied Microbiology, Molecular and Cellular Biosciences Research Foundation. All rights reserved.