奶牛乳腺炎源乳房链球菌关键毒力因子及调控机制研究进展OA

Streptococcus uberis(S.uberis)is a major environmental pathogen responsible for bovine mastitis.Its pronounced genetic diversity and strong environmental adaptability enable the establishment of persistent intramammary infections,making it a leading cause of chronic and recurrent mastitis.The widespread presence of S.uberis in bedding materials,milking equipment,and various farm environments,together with its often subtle and difficult-to-detect transmission,presents a substantial challenge to mastitis control.Although advances in molecular biology and multi-omics technologies have accelerated,there remains a lack of systematic elucidation regarding the functions of virulence factors,their coordinated interactions,and the upstream regulatory networks in S.uberis.This gap limits a comprehensive understanding of its pathogenic mechanisms.To provide a more comprehensive understanding of the pathogenic mechanisms of S.uberis,this review summarizes its key virulence factors and regulatory mechanisms,with a focus on the course of infection:Adhesion and colonization,nutrient acquisition,immune evasion and inflammation modulation,and virulence regulation networks.During adhesion and colonization,adhesion molecules,fibronectin-binding proteins,glyceraldehyde-3-phosphate dehydrogenase,and plasminogen activators mediate attachment to and internalization into mammary epithelial cells.During nutrient acquisition,lactoferrin-binding proteins and zinc-binding proteins facilitate competitive uptake of essential metal ions,such as Fe2+and Zn2+allowing the bacterium to maintain metabolic homeostasis under nutritional immunity.In the immune evasion and inflammation-modulation phase,serine proteases,C5a peptidases,and the hyaluronic acid capsule synthesis cluster suppress phagocytosis and alter inflammatory responses,thereby promoting infection persistence.At the regulatory level,the global transcriptional regulator Vru coordinates the expression of multiple virulence-related genes and likely serves as a central node within the broader regulatory landscape.By integrating evidence across different stages of infection,this review delineates a continuous pathogenic framework in which S.uberis progresses from adhesion,nutritional competition to immune interference,and identifies regulatory systems that may affect virulence expression.The synthesis of current advances and existing knowledge gaps provides a conceptual basis for improving strategies aimed at effective mastitis control and for guiding future vaccine development and anti-virulence interventions targeting S.uberis.