Bio-chemistry/Bio-medical

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Browsing Bio-chemistry/Bio-medical by Subject "coliforms"

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    Analysis of Microbial Quality of Drinking Water in Njoro Sub-county, Kenya
    (2019-10) Kirianki, Philip; Othira, J.O.; Kiruki, Silas;
    Drinking water should be free of microbial pathogens so as to be regarded as potable water and safe for drinking. However, water is prone to fecal contaminants which are the sources of gastrointestinal illnesses. In Njoro Sub-county, river Njoro and rain water are the primary sources of water which also reduces during dry seasons. Other water sources include boreholes, dams, springs and wells while in other cases, the residents store water in household storage containers for future uses. In this study, various water sources and water stored in different containers in Njoro Sub-County was analyzed for its microbial quality. Various microbial parameters such as total viable colony counts (TVCC), total coliforms (TC) and fecal coliforms (FC) were evaluated by use of the culture methods. Most of the water sources were contaminated. TVCC ranged from 0.47 to 1.76 CFU/1mL in water sources and 0.48 to 2.04 CFU/1mL in domestic storage containers. TC was in the range of between 0.30 to 1.89 CFU/100mL in water sources and 0.59 to 2.47 CFU/100mL in domestic storage containers. The mean FC in water sources ranged from 0.10 to 1.68 CFU/100mL and from 0.81 CFU/100mL domestic storage containers. Therefore frequent water testing should be performed by water authorities as recommended by WHO. At households, the people should employ various water treatment methods and practice safe water handling so as to avoid gastrointestinal infections.
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    Bacteriological quality and diarrhoeagenic pathogens on River Njoro and Nakuru Municipal water, Kenya
    (2011-09) Kiruki, Silas 1*; Limo, Kiprop Moses1; Mwaniki, Njagi Eliud Nyaga 2; Okemo, Paul Owuor 3
    Waterborne diarrhoeal pathogens are considered a re-emerging threat and are responsible for considerable morbidity and mortality, especially in developing countries. The objective of this study was to determine bacteriological quality, biochemical oxygen demand and presence of diarrhoeagenic pathogens in water samples collected from River Njoro and Nakuru Municipal water. A total of 432 samples were tested, 216 from River Njoro and 216 from Nakuru Municipal water. Bacteria indicator numbers (arithmetic mean MPN/ml) varied from 24.4 (source) to >2700.0 (midstream) for total coliforms and 3.6 (source) to 1880.0 (midsream) for faecal coliforms in River Njoro. There was a consistent increase in bacteria loading as the river flowed from the source (Nessuit) to downstream sites. The biochemical oxygen demand (BOD) ranged from 2.0 mg/L at the source of the river to 44.0 mg/L at Njoro bridge. The frequency of enteropathogenic bacteria isolated in 216 samples collected from River Njoro were; Aeromonas hydrophila 52%, Hafnia alvei 29.2%, Salmonella typhimurium 18%, Salmonella typhi 17%,Enteroaggregative Escherichia coli 9.2%, Necrotoxigenic E. coli 7.4% and Enteropathogenic E. coli 3.2%. Only H. alvei 4.6% and A. hydrophila 6.5% were isolated from Nakuru Municipality water and no enteropathogens were detected at Nakuru town centre, Kiti and Milimani estates. River Njoro has been found to be heavily contaminated with indicator bacteria, organic material and diarrhoegenic pathogens. This suggests need to educate people regarding good health practices, proper waste disposal, boiling drinking water and seek alternative sources of drinking water in the study area.