Detection of active pathogenic bacteria under stress conditions using lytic and specific phage

Abstract

In this study, we have monitored the potential activity of a foodborne and waterborne pathogenic bacterium, Salmonella typhi, under starvation conditions. The interaction between lytic phage and starved-VBNC pathogenic bacteria was studied to establish reliable methods for the detection of active cells before resuscitation. The analysis of phage kinetic parameters has demonstrated the flexibility of lytic with the quantity and mainly the quality of host cells. After 2 h of phage-starved-VBNC bacteria interaction, the reduction of phage amplification rate can reveal the ability of specific-lytic phage to recognize and to attach to their host cells with a probability of burst and release of infectious phages by active bacteria. After an extension of the latent period, the boost of the phage amplification rate was directly related to the positive interaction between potential intracellular 'engaged' phages and potential active bacteria. Furthermore, the modeling of the Salmonella-specific phage growth cycle in relationship with starved host cells can highlight the impact of the viability and the activity state of the host cells on the phage's growth cycle.