Backyard Farms Represent a Source of Wide Host Range Salmonella Phages That Lysed the Most Common Salmonella Serovars

ABSTRACT The genus Salmonella has more than 2,600 serovars, and this trait is important when considering interventions for Salmonella control. Bacteriophages that are used for biocontrol must have an exclusively lytic cycle and the ability to lyse several Salmonella serovars under a wide range of environmental conditions. Salmonella phages were isolated and characterized from 34 backyard production systems (BPSs) with a history of Salmonella infections. BPSs were visited once, and cloacal or fecal samples were processed for phage isolation. Four hosts, Salmonella serovars Enteritidis, Heidelberg, Infantis, and Typhimurium, were used for phage isolation. The host range of the phages was later characterized with a panel of 23 Salmonella serovars (serovar diversity set) and 31 isolates obtained from the same farms (native set). Genetic relatedness for 10 phages with a wide host range was characterized by restriction fragment length polymorphism, and phages clustered based on the host range. We purified 63 ph...