Usefulness of faecal Streps as indicator of presence of Salmonella sp. and Vibrio cholerae in sewage effluents

Abstract

Enteric pathogens are the most frequent cause of diarrheal illness, which account for an annual mortality rate of three million people and an estimated four billion infection worldwide. One way of preventing this is by ensuring proper sewage treatment. The study was carried out to provide data for level of microbiological contamination as well as baseline data for the future assessment and monitoring of pollution levels of sewage lagoons around Kenyatta university sewage treatment plant. It was also aim to find out the indicator organism that is suitable for the assessment and monitoring of faecal pollution. This paper contains the results of isolation, identification and quantification of faecal coliforms, streps, Salmonella sp. and Vibrio cholerae from Kenyatta university sewage treatments ponds. For the faecal coliforms, detection and quantification was done using the Most Probable Number (MPN) technique. The isolation and enumeration of faecal streps, Salmonella sp. and V. cholerae was done using standard methods. Correlation of faecal coliforms with Salmonella sp. and V. cholerae was 85% and 2% respectively. For the faecal streps, correlation with Salmonella sp. and V. cholerae was 78% and 12% respectively. This indicates that faecal streps should be included as indicator organisms of the potential health hazards of polluted water. Most international drinking water quality guidelines and standards include bacterial indicators as a measure of microbial water quality, and for compliance reporting. The results from the study support the idea of using both the faecal streps and coliforms as indicators of faecal pollution.