Evaluation of a BWTK for detection of total coliforms, E. coli and emerging pathogens from drinking water: comparison...

A defined substrate method media in bacteriological water testing kit (BWTK) has been developed to recover and detect the presence/absence of total coliforms and emerging pathogens from drinking water without the need for the confirmatory or complete tests. This method is based on technology that uses a hydrolysable substrate as a specific indicator- nutrient for the target microbes. To perform the test, one only has to add water to the ingredients in the BWTK and incubate at room temperature for a time period of 48 hrs. The target microbes remain viable in the positive kit for at least 10 days and further bacterial isolates from BWTK were characterized phenotypically, molecular identified by sequencing of 16SrRNA gene and antibiotic sensitivity was determined. All of the emerging bacterial isolates were haemolytic and multiple resistant to antibiotics. The epidemiological surveillance of drinking water revealed the occurrence of emerging pathogens responsible for causing acute gastrointestinal illness, soft tissue infections, meningitis, enteritis to acute mesenteric lymphadenitis as Yersinia enterocolitica (94%) and Aeromonas hydrophila (79%). The conventional methods (IS-10500-1991 BIS New Delhi, India) cannot predict the presence of these potentially enteropathogenic microorganisms in drinking water. There are currently no suitable microbiological criteria for the detection of emerging pathogens. In response to these limitations a BWTK has been developed for regularly monitoring of drinking water quality for appraisal to public health officials and take corrective measures regarding health risk when desired.