Characterization of a Broad-Host-Range Lytic Phage SHWT1 Against Multidrug-Resistantand Evaluation of Its Therapeutic Efficacyand.

Abstract

Inappropriate use of antibiotics has accelerated to the emergence of multidrug-resistant bacteria, becoming a major health threat. Moreover, bacterial biofilms contribute to antibiotic resistance and prolonged infections. Bacteriophage (phage) therapy may provide an alternative strategy for controlling multidrug-resistant bacterial infections. In this study, a broad-host-range phage, SHWT1, with lytic activity against multidrug-resistantwas isolated, characterized and evaluated for the therapeutic efficacyand. Phage SHWT1 exhibited specific lytic activity against the prevalentserovars, such asPullorum,Gallinarum,Enteritidis, andTyphimurium. Morphological analysis showed that phage SHWT1 was a member of the familyand the order. Phage SHWT1 had a latent period of 5 min and burst size of ~150 plaque-forming units (PFUs)/cell. The phage was stable from pH 3-12 and 4-65°C. Phage SHWT1 also showed capacity to lyseplanktonic cells and inhibit the biofilm formation at optimal multiplicity of infection (MOI) of 0.001, 0.01, 0.1, and 100, respectively. In addition, phage SHWT1 was able to lyse intracellularwithin macrophages. Genome sequencing and phylogenetic analyses revealed that SHWT1 was a lytic phage without toxin genes, virulence genes, antibiotic resistance genes, or significant genomic rearrangements. We found that phage SHWT1 could successfully protect mice against.and.infection. Elucidation of the characteristics and genome sequence of phage SHWT1 demonstrates that this phage is a potential therapeutic agent against the salmonellosis caused by multidrug-resistant.