Use of lytic phage to control Salmonella typhi's viability after irradiation by pulsed UV light

The infectivity rates of Salmonella typhi's phage was used as a bio-indicator to detect the presence of viable but non cultivable bacteria after irradiation by an increasing number of pulsed UV light. Indeed, the combination of a conventional method used to measure colony-forming ability of UV-irradiated bacteria, and the study of relationship between host bacteria and a suitable phage can reveal the existence of active bacteria which lose the cultivability in usual culture media, but keep viability and phage susceptibility.