DISTRIBUTION AND DIVERSITY OF ANTIBIOTIC RESISTANT BACTERIA IN NJORO RIVER IN NAKURU COUNTY

Abstract

Many in-stream activities occur in River Njoro whereby communities fetch water for domestic use, watering of animals and Laundry. Furthermore communities use the river for irrigation, washing of motor vehicles and for sewage disposal. Of major concern is that many pharmaceuticals used in the farms and hospitals as well as antibiotic resistant microbes find their way to the river in runoff and sewage. Presence of antibiotic resistance in river water exposes human and animals to contamination during these in-stream activities.  Thus the current study determined the levels of bacteria resistant to various types of antibiotics both medical and veterinary used for disease treatment in the catchment. The levels of residual antibiotics present in river water and sediments were investigated as well as various physical chemical conditions and indicators of faecal pollution in the river. The total numbers of bacteria resistant to five antibiotics studied varied in sediments collected in different sites (ANOVA, P < 0.05). Turkana site showed highest resistance to ampicillin, tetracycline and streptomycin while Njoro canning factory showed highest numbers for gentamycin and chloramphenical. Indicators of faecal pollution were found in all sites even in Sigotik (the most upstream site) recording an E. coli density of 4.13×104±15.28 per 100 ml of water. Physical-chemical measurements were able to show site differences. A typical example is BOD whereby Njoro Canning factory had the highest value of 6.99±0.20 mg L^-1whereas Sigotik the furthest point upstream had BOD of 1.28±0.13 mg L^-1. Positive Shigella spp., E.coli spp., Salmonella spp., Vibrio cholera and V. parahaemolyticus were recorded in Turkana and Ngata sites. There is cause for alarm due to the high antibiotic resistant bacteria in River Njoro. We recommend proper treatment of the river water before use or alternative safer water sources for consumption.