Seasonal Evaluation of the Bacteriological Quality of Agangwu Stream in Enugu State, Nigeria

Abstract: Water is essential to life but many people do not have access to clean and safe drinking water while many even die of water borne bacterial infections. The sanitary quality of stream water cannot be predicted due to behavioral differences of the users and their living condition. This investigation was carried out on the seasonal evaluation of the microbiological quality of Agangwu Stream in Enugu State, Nigeria. A total of eighteen (18) stream water samples collected at wet and dry seasons comprised of six (6) water samples each from the upstream, midstream and downstream locations. They were subjected to a wide range of analytical assessments like the multiple tube fermentation method according to APHA, 2016. Then, the bacteria isolates were characterized and identified morphologically and biochemically using standard microbiological techniques. The dilution pattern showed varying coliform concentration especially for MS1 (3-0-2) and DS1 (3-1-2). E. coli, the most common fecal coliform appeared in both seasons with the highest (most probable number) MPN index of 75mpn/100ml (95% confidence limits: 14-230) in dry season and the least MPN index of 1.5mpn/100ml (95% confidence limits: 3 - 44) in wet season. Even though the values were statistically insignificant (P=>0.5). The molecular identification of some of the isolates from the stream water samples confirmed various pathogens, including Salmonella enterica subsp. Enterica, Escherichia coli, etc. The MPN index for both seasons reveal a clear gradient of increasing fecal contamination from upstream to downstream sections of Agangwu Stream. These findings demonstrate that Agangwu stream is definitely not safe for direct human consumption or recreational use without adequate treatment. Rather, there is need for regular monitoring, effective water treatment, and public health interventions to mitigate the risks associated with waterborne diseases.