| 摘要 |
Viral contamination in water samples is detected using a medium which includes both a substrate for beta -galactosidase and E. coli with elevated levels of intracellular beta -galactosidase. The substrate is chosen to undergo a detectable change (e.g., colorimetric, fluorometric, photometric, etc.) upon cleavage by beta -galactosidase. A water sample to be tested for viral contamination is added to the medium. If coliphages are present in the water sample, they will infect, multiply within, and subsequently lyse the E. coli host. Lysis of the E. coli will allow the release of the intracellular beta -galactosidase into the media, whereupon the enzyme will cleave the substrate for a detectable reaction. In one particular application, a colorimetric reagent that serves as a substrate for beta -galactosidase is dissolved or dispersed within an agar medium, and in another particular application, a colorimetric reagent that serves as a substrate for beta -galactosidase is dissolved or dispersed within a liquid medium. Color changes which result from lytic cell infection of the E. coli hosts are easily monitored by researchers or laboratory technicians. The presence of coliphages in a water sample is indicative of the presence of harmful human and animal enteric viruses in the water. |
