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Occurrence of Waterborne Pathogens in Lake Zwai and Drinking Water System of Batu (Zwai) Town, Ethiopia: In Relation to Indicator Bacteria and Physicochemical Parameters

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dc.contributor.advisor Assefa, Fassil (PhD)
dc.contributor.author Mekonnen, Mekuria
dc.date.accessioned 2018-07-16T07:35:54Z
dc.date.available 2018-07-16T07:35:54Z
dc.date.issued 2014-06
dc.identifier.uri http://localhost:80/xmlui/handle/123456789/8659
dc.description.abstract Surface and drinking waters are routinely analyzed for physicochemical parameters and indicator bacteria. However, the presence/absence of indicator bacteria may not necessarily be equally indicative of the presence of pathogens. In this study, the physicochemical and bacterial indicator of water quality parameters were compared with the occurrences of waterborne bacterial pathogens from water and sediment samples of Lake Zwai, Meki and Qatar Rivers and drinking water system of Batu (Zwai) Town. Seventy eight water and sediment samples were collected from April through November 2013 and analyzed for the physicochemical parameters (pH, temperature, electrical conductivity, dissolved oxygen, nitrate, nitrite, ammonia and phosphate), indicator bacteria (Escherichia coli, Enterococci, Clostridium perfringens, total and fecal coliforms) and pathogenic bacteria (Salmonella, Shigella, Vibrio cholera, Vibrio spp., E. coli O157:H7) using standard methods. All except temperature, the physicochemical parameters in reservoir and tap water samples met the maximum permissible value for drinking water. The highest proportion of pathogenic bacteria was detected from lake sediment (52.7%), followed by Meki and Qatar Rivers sediment (50.0%), lake water (40.4%), Qatar (33.3%) and Meki (26.7%) River water, tap water (4.8%) and none from reservoir water samples. Vibrio cholera, Vibrio spp, Salmonella and Shigella were commonly detected from surface water and sediment samples (48.9%), whereas, E. coli O157:H7 was limited in a few sources with low percentage (3.3%). With respect to the microbial load of the tested organisms, the highest count of 4.20 log CFU/100 g of indicator bacteria was detected from river sediment and the lowest count of 0.42 log CFU/100 ml recorded from reservoir water. Differences in concentration of indicator bacteria were statistically significant (P<0.0001) between sample sources. Spearman rank correlations show some indicators and physicochemical parameters were significantly correlated with the presence of bacterial pathogens. Shigella was better significantly correlated with both indicator and pathogenic bacteria. Since surface and drinking water distribution system were contaminated with bacteria, the need to develop more effective monitoring and efficient treatment mechanism of the drinking water source with respect to microbial contamination is necessary. Keywords/phrases Enterococci, fecal coliforms, Salmonella, Shigella, waterborne diseases en_US
dc.language.iso en en_US
dc.publisher Addis Ababa Universty en_US
dc.subject Enterococci en_US
dc.subject Fecal coliforms en_US
dc.subject Salmonella en_US
dc.subject Shigella en_US
dc.subject Waterborne diseases en_US
dc.title Occurrence of Waterborne Pathogens in Lake Zwai and Drinking Water System of Batu (Zwai) Town, Ethiopia: In Relation to Indicator Bacteria and Physicochemical Parameters en_US
dc.type Thesis en_US


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