摘要

单核细胞增多性李斯特氏菌负责健康个体的胃肠炎和免疫功能低下患者的严重侵袭性疾病。 在三种鉴定出的单核细胞增生李斯特氏菌进化谱系中，谱系I菌株在流行性李斯特菌病暴发中被过量表达，但是该谱系菌株较高毒力潜力的机制仍然难以捉摸。 在这里，我们表明，Listeriolysin S（LLS），毒力因子只存在于沿袭我菌株的子集中，是一种在口腔感染小鼠的肠道中高度表达的细菌素，改变了宿主肠道微生物群并促进了单核细胞增生李斯特氏菌 ，以及更深的器官感染。 据我们所知，这些结果因此将LLS鉴定为单核细胞增生利斯特氏菌中描述的第一种细菌素，并且通过单核细胞增生利斯特氏菌流行菌株对宿主微生物群的联合调节来增加毒力。

Listeria monocytogenes is responsible for gastroenteritis in healthy individuals and for a severe invasive disease in immunocompromised patients. Among the three identified L. monocytogenes evolutionary lineages, lineage I strains are overrepresented in epidemic listeriosis outbreaks, but the mechanisms underlying the higher virulence potential of strains of this lineage remain elusive. Here, we demonstrate that Listeriolysin S (LLS), a virulence factor only present in a subset of lineage I strains, is a bacteriocin highly expressed in the intestine of orally infected mice that alters the host intestinal microbiota and promotes intestinal colonization by L. monocytogenes, as well as deeper organ infection. To our knowledge, these results therefore identify LLS as the first bacteriocin described in L. monocytogenes and associate modulation of host microbiota by L. monocytogenes epidemic strains to increased virulence.

http://www.pnas.org/content/113/20/5706.short