Phage Lysin AVPL Had Lytic Activity against in a Mouse Bacteremia Model.

() is a swine pathogen that can cause sepsis, meningitis, endocarditis, and other infectious diseases; it is also a zoonotic pathogen that has caused a global surge in fatal human infections. The widespread prevalence of multidrug-resistant strains and the decline in novel antibiotic candidates have necessitated the development of alternative antimicrobial agents. In this study, AVPL, the () phage lysin, was found to exhibit efficient bactericidal activity and broad lytic activity against multiple serotypes of . A final concentration of 300 μg/mL AVPL reduced counts by 4-4.5 log10 within 1 h in vitro. Importantly, AVPL effectively inhibited 48 h biofilm formation and disrupted preformed biofilms. In a mouse model, 300 μg/mouse AVPL protected 100% of mice from infection following the administration of lethal doses of multidrug-resistant type 2 (SS2) strain SC19, reduced the bacterial load in different organs, and effectively alleviated inflammation and histopathological damage in infected mice. These data suggest that AVPL is a valuable candidate antimicrobial agent for treating infections.