Assessment of Clostridium perfringens in determination of fecal pollution of drinking water in comparion to indicators bacteria

Introduction & Fecal coliforms and Escherichia coli have been conventionally used as indicators of microbial pollution of drinking water. The European Directive on drinking water quality has included Clostridium perfringens as one of the microbiological parameters to be determined in control of the water quality for human consumption. This study was carried out to evaluate the efficiently of Clostridium perfringens in compare to Fecal coliforms and Escherichia coli in detection of microbial pollution of water sources. In this study, 60 raw water samples were collected from drinking water resources in the Isfahan province, Iran from May to November 2012 Fecal coliforms, Escherichia coli, Fecal streptococci and Clostridium perfringens were investigated by multiple-tube fermentation technique (MFT) using double-strength medium in 10 series of tubes according to the Standard Methods. Statistical analyses were carried out using SPSS 18 at the 95% confidence level (α = 0.05). The results of this study showed that 46.2 % of water samples being positive in regard to fecal contamination at least for one bacterial indicator. Clostridium perfringens was the most frequently detected indicator (36.5%) followed by fecal streptococci (34.6%), fecal coliforms (28.8%) and Escherichia coli (25%). Pearson coefficient showed that the highest correlation was found between Clostridium perfringens and Fecal streptococci (0.88). Clostridium perfringens is an important indicator for water quality monitoring in communities where raw water used direct human consumption without treatment. Testing for the spores of this bacterium can provide an added margin of safety for prediction of microbial quality of drinking water.