无乳链球菌毒力因子的研究进展

Research progress on virulence factors and vaccine of Streptococcus agalactiae

无乳链球菌(Streptococcus agalactiae)又称为B组链球菌(group B Streptococcus,GBS),多定殖于人体的生殖道和胃肠道,是围产期(perinatal period)的主要致病菌之一,可引起孕产妇感染,严重时甚至危及新生儿的生命,还会造成老年人和免疫力低下人群的感染。无乳链球菌具有许多毒力因子,分别与细菌黏附、免疫逃避、侵袭损伤相关。这些毒力因子能够使细菌在人体内持续存在,加大传播的可能性,并可加重感染,影响患者的预后。目前尚无无乳链球菌疫苗被批准使用,但近年来针对无乳链球菌疫苗研发取得了较大进展。由于无乳链球菌的致病性受到细菌感染及定殖策略的影响,研究其内在机制可为改善和设计预防无乳链球菌疾病的策略提供有益帮助。现就无乳链球菌毒力因子的相关机制作一概述。

Streptococcus agalactiae(S.agalactiae),also known as group B Streptococcus(GBS),colonizes both the reproductive tract and gastrointestinal tract of humans.It is one of the main pathogens during perinatal period that can cause maternal infection and even endanger newborns' lives in severe cases.In addition,the pathogenic bacterium can also infect elderly people and those with weakened immune systems.S.agalactiae encodes many virulence factors that are related to bacterial adhesion,immune escape,and invasion damage.The secretion of these virulence factors contributes to persistently survive of S.agalactiae in human bodies as well as possibility to increase transmission.The virulence factors may also aggravate infection and worsen prognosis in patients.Currently,researches and developments of vaccines against bacterial adhesion and immune evasion have shown great progress,although there is no licensed vaccine to control S.agalactiae infection.Since pathogenicity of S.agalactiae is affected by bacterial infection and colonization strategies,studying its internal mechanism can provide useful help for improving and designing strategies to prevent S.agalactiae diseases.This article reviews related mechanisms of S.agalactiae virulence factors.