Development of molecular and enzymatic kits for the detection of total coliforms and Escherichia coli in water samples

Abstract

The drinking water is one of the main sources of infectious diseases. It is of major importance to keep a good water quality monitoring. The need for more rapid, sensitive and specific tests is essential; not only for water industry, but for a better public safety. Therefore, detection of microbial indicators of potential pathogens in water is the solution to the prevention and recognition of problems related to human health and safety. The main purpose of this work is to develop commercial kits for the detection of the extensively used as indicator organisms: Escherichia coli and total coliforms. An enzymatic method of detection of these microorganisms is being developed based on the enzymes β-Dglucuronidase and β-D-galactosidase, respectively. The results are visible in 18 h for 1 CFU. In order to achieve a higher level of sensitivity and specificity, molecular detection using the Polymerase Chain Reaction (PCR) technique is being investigated. Three primers were selected for identification of total coliforms, E. coli and E. coli with other enteric pathogens. At this moment, we achieved a sensitivity level of 676 CFU in 8 h, which is already a good achievement but there is still more research to be done in order to accomplish the 1 CFU detection.