Multireceptor phage cocktail against to circumvent phage resistance.

Non-Typhoidal (NTS) is one of the most common food-borne pathogens worldwide, with poultry products being the major vehicle for pathogenesis in humans. The use of bacteriophage (phage) cocktails has recently emerged as a novel approach to enhancing food safety. Here, a multireceptor phage cocktail of five phages was developed and characterized. The cocktail targets four receptors: O-antigen, BtuB, OmpC, and rough strains. Structural analysis indicated that all five phages belong to unique families or subfamilies. Genome analysis of four of the phages showed they were devoid of known virulence or antimicrobial resistance factors, indicating enhanced safety. The phage cocktail broad antimicrobial spectrum against , significantly inhibiting the growth of all 66 strains from 20 serovars tested . The average bacteriophage insensitive mutant (BIM) frequency against the cocktail was 6.22 × 10 in . Enteritidis, significantly lower than that of each of the individual phages. The phage cocktail reduced the load of in inoculated chicken skin by 3.5 log CFU/cm after 48 h at 25°C and 15°C, and 2.5 log CFU/cm at 4°C. A genome-wide transduction assay was used to investigate the transduction efficiency of the selected phage in the cocktail. Only one of the four phages tested could transduce the kanamycin resistance cassette at a low frequency comparable to that of phage P22. Overall, the results support the potential of cocktails of phage that each target different host receptors to achieve complementary infection and reduce the emergence of phage resistance during biocontrol applications.