Characterization of vB_SalS_PSa2, a T5-like Demerecviridae bacteriophage, and its potential use in food matrices.

This study characterizes a newly isolated Demerecviridae phage, named vB_SalS_PSa2, belonging to the phage T5 group. The main variations between vB_SalS_PSa2 and T5 concern structural proteins related to morphology and host recognition. vB_SalS_PSa2 is infective to 19 out of the 25 tested Salmonella enterica (including the rare "Sendai" and "Equine" serotypes) and Escherichia coli isolates, most of them being multidrug resistant. vB_SalS_PSa2 displayed good thermal stability (4–60 °C) and broad pH stability (4.0–12.0). It also exhibited antibacterial activity against S. enterica sv. Paratyphi A Enb50 at 4 °C in milk during the whole tested period (5 d), and for 3–6 h at both 25 and 37 °C. Furthermore, vB_SalS_PSa2 was able to inhibit biofilm formation and to show degradation activity on mature biofilms of E. coli K12 and S. enterica sv. Paratyphi Enb50 in both LB and milk. Altogether, these results indicate that phage vB_SalS_PSa2 is a valuable candidate for controlling foodborne S. enterica and E. coli pathogens. • vB_SalS_PSa2 is a newly isolated Demerecviridae phage belonging to the T5 group. • vB_SalS_PSa2 displays a wide host range to tested clinical isolates of Salmonella and E. coli , most being multidrug resistant. • vB_SalS_PSa2 is stable in a relative broad temperature and pH range. • vB_SalS_PSa shows good antibacterial effect in milk under refrigerated conditions. • vB_SalS_PSa2 shows good inhibition effect on biofilm formation and degradation on the mature biofilms of the tested targets. [ABSTRACT FROM AUTHOR]