Liévin V, Peiffer I, Hudault S, Rochat F, Brassart D, Neeser J R, Servin A L
Institut National de la Santé et de la Recherche Médicale, Unité 510, UFR de Pharmacie, Université Paris XI, 92296 Châtenay-Malabry, France.
Gut. 2000 Nov;47(5):646-52. doi: 10.1136/gut.47.5.646.
The gastrointestinal microflora exerts a barrier effect against enteropathogens. The aim of this study was to examine if bifidobacteria, a major species of the human colonic microflora, participates in the barrier effect by developing antimicrobial activity against enterovirulent bacteria.
Antibacterial activity was examined in vitro against a wide range of Gram negative and Gram positive pathogens. Inhibition of Salmonella typhimurium SL1334 cell association and cell invasion was investigated in vitro using Caco-2 cells. Colonisation of the gastrointestinal tract in vivo by bifidobacteria was examined in axenic C3/He/Oujco mice. Antimicrobial activity was examined in vivo in axenic C3/He/Oujco mice infected by the lethal S typhimurium C5 strain.
Fourteen human bifidobacterium strains isolated from infant stools were examined for antimicrobial activity. Two strains (CA1 and F9) expressed antagonistic activity against pathogens in vitro, inhibited cell entry, and killed intracellular S typhimurium SL1344 in Caco-2 cells. An antibacterial component(s) produced by CA1 and F9 was found to be a lipophilic molecule(s) with a molecular weight of less than 3500. In the axenic C3/He/Oujco mice, CA1 and F9 strains colonised the intestinal tract and protected mice against S typhimurium C5 lethal infection.
Several bifidobacterium strains from resident infant human gastrointestinal microflora exert antimicrobial activity, suggesting that they could participate in the "barrier effect" produced by the indigenous microflora.
胃肠道微生物群对肠道病原体具有屏障作用。本研究旨在探讨双歧杆菌（人类结肠微生物群的主要菌种之一）是否通过产生针对肠道致病细菌的抗菌活性来参与屏障作用。
在体外检测对多种革兰氏阴性和革兰氏阳性病原体的抗菌活性。使用Caco - 2细胞在体外研究对鼠伤寒沙门氏菌SL1334细胞黏附和细胞侵袭的抑制作用。在无菌C3/He/Oujco小鼠体内检测双歧杆菌在胃肠道的定植情况。在感染致死性鼠伤寒沙门氏菌C5菌株的无菌C3/He/Oujco小鼠体内检测抗菌活性。
检测了从婴儿粪便中分离出的14株人类双歧杆菌菌株的抗菌活性。两株菌株（CA1和F9）在体外对病原体表现出拮抗活性，抑制细胞进入，并在Caco - 2细胞中杀死细胞内的鼠伤寒沙门氏菌SL1344。发现由CA1和F9产生的一种抗菌成分是分子量小于3500的亲脂性分子。在无菌C3/He/Oujco小鼠中，CA1和F9菌株在肠道定植，并保护小鼠免受鼠伤寒沙门氏菌C5致死性感染。
来自婴儿胃肠道常驻微生物群的几株双歧杆菌菌株具有抗菌活性，表明它们可能参与了本土微生物群产生的“屏障作用”。
