Novel primer designing and PCR-AFLP approach for an expeditious detection of coliforms in potable waters

ABSTRACT

Molecular techniques involving 16S rRNA gene have long been proved to be a mainstay of sequence-based bacterial analysis and enhance the competence of bacterial removal in drinking water and food. The main goal of this analysis was to reduce the time of detection of total coliforms by developing 16S rRNA based DNA markers by targeting variable region in the 16S rRNA gene position of V2 and V9. Coliform specific primers (189F and 1447R) were designed to amplify total coliform with an amplicon size of 1300 bp. The PCR product was later digested with Hind III and BseRI (restriction enzymes) to differentiate the type of contamination caused by fecal and non-fecal coliforms respectively. The digested amplicons were run on agarose gel electrophoresis and contamination levels were estimated based on the respective band pattern. This method can be applicable to know the coliform contamination levels of potable waters, in food and beverage industries within a short period of time. To our knowledge, this is the first report on newly designed primers which not only amplify coliform bacteria, followed by various restriction digestions of these amplicons but also provides unique band patterns to identify coliforms at genus level.