Corr Sinéad C, Li Yin, Riedel Christian U, O'Toole Paul W, Hill Colin, Gahan Cormac G M
Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland.
Proc Natl Acad Sci U S A. 2007 May 1;104(18):7617-21. doi: 10.1073/pnas.0700440104. Epub 2007 Apr 24.
The mechanisms by which probiotic strains enhance the health of the host remain largely uncharacterized. Here we demonstrate that Lactobacillus salivarius UCC118, a recently sequenced and genetically tractable probiotic strain of human origin, produces a bacteriocin in vivo that can significantly protect mice against infection with the invasive foodborne pathogen Listeria monocytogenes. A stable mutant of Lb. salivarius UCC118 that is unable to produce the Abp118 bacteriocin also failed to protect mice against infection with two strains of L. monocytogenes, EGDe and LO28, confirming that bacteriocin production is the primary mediator of protection against this organism. Furthermore, Lb. salivarius UCC118 did not offer any protection when mice were infected with a strain of L. monocytogenes expressing the cognate Abp118 immunity protein AbpIM, confirming that the antimicrobial effect is a result of direct antagonism between Lb. salivarius and the pathogen, mediated by the bacteriocin Abp118.
益生菌菌株增强宿主健康的机制在很大程度上仍未明确。在此，我们证明唾液乳杆菌UCC118，一种最近测序且遗传易处理的源自人类的益生菌菌株，在体内产生一种细菌素，该细菌素能显著保护小鼠免受侵袭性食源性病原体单核细胞增生李斯特菌的感染。唾液乳杆菌UCC118的一个稳定突变体，其无法产生Abp118细菌素，也不能保护小鼠免受两株单核细胞增生李斯特菌（EGDe和LO28）的感染，这证实了细菌素的产生是抵御该病原体的主要保护介质。此外，当小鼠感染表达同源Abp118免疫蛋白AbpIM的单核细胞增生李斯特菌菌株时，唾液乳杆菌UCC118没有提供任何保护作用，这证实了抗菌作用是唾液乳杆菌与病原体之间直接拮抗的结果，由细菌素Abp118介导。
