Abstract: Streptococcus suis is a critical zoonotic pathogen capable of causing meningitis, septicemia, and sudden death in pigs, resulting in substantial economic losses. Furthermore, it can be transmitted to humans through contact, leading to fatal diseases. In recent years, the misuse of antibiotics has led to the widespread emergence of multi-drug resistant strains, significantly diminishing the efficacy of traditional antimicrobial therapies. Phage endolysins, as cell wall hydrolases encoded by bacteriophages, can specifically degrade the bacterial cell wall and exhibit advantages such as high bactericidal efficiency, low propensity to induce resistance, and minimal disruption to microbial communities, making them promising candidates as antibiotic alternatives. This review systematically summarizes the fundamental characteristics, mechanisms of action, cloning and expression, and production processes of phage endolysins, describes the pathogenic characteristics and the limitations of current prevention and control measures of S. suis, summarizes the research progress on phage endolysins against S. suis in terms of the in vitro antibacterial activity and in vivo animal studies, discusses potential challenges and corresponding strategies in practical applications related to delivery, immunogenicity, production and regulation, and outlines future research directions, including engineering modification, development of combination therapies, and clinical translation, with the aim of providing novel solutions to address S. suis infections and antibiotic resistance challenges.

Key words: Streptococcus suis, phage endolysins, antimicrobial resistance, antibiotic alternatives, application progress