摘要

肠球菌，特别是耐万古霉素肠球菌（VRE），是医院获得性感染的主要原因。促进对肠球菌的肠道抵抗可以降低VRE感染的风险。我们调查了两种乳酸杆菌菌株预防肠道VRE的效果。我们使用基于抗生素诱导的微生物失调症的肠内定殖小鼠模型来模拟肠球菌过度生长和VRE持续性。每种乳杆菌属物种在抗生素治疗前一周开始每天施用至小鼠，直至抗生素和VRE接种后两周。在这两种菌株中，副干酪乳杆菌CNCM I-3689显着降低了粪便中的VRE数量，表明VRE的降低有所改善。纵向微生物群分析表明补充副干酪乳杆菌CNCM I-3689与更好地回收Bacteroidetes门成员有关。选择的宿主基因的胆汁盐分析和表达分析显示补充了副干酪乳杆菌CNCM I-3689时营养（人类LL-37）的石胆酸盐和回肠表达的水平增加。虽然不排除副干酪乳杆菌CNCM I-3689对VRE减少的直接影响，但我们的数据提供了可能的抗VRE机制的线索，支持通过肠道微生物群的间接抗VRE作用。这项工作在抗生素诱导的生精障碍后维持针对机会性肠球菌的非抗生素策略。

Enterococci, in particular vancomycin-resistant enterococci (VRE), are a leading cause of hospital-acquired infections. Promoting intestinal resistance against enterococci could reduce the risk of VRE infections. We investigated the effects of two Lactobacillus strains to prevent intestinal VRE. We used an intestinal colonisation mouse model based on an antibiotic-induced microbiota dysbiosis to mimic enterococci overgrowth and VRE persistence. Each Lactobacillus spp. was administered daily to mice starting one week before antibiotic treatment until two weeks after antibiotic and VRE inoculation. Of the two strains, Lactobacillus paracasei CNCM I-3689 decreased significantly VRE numbers in the feces demonstrating an improvement of the reduction of VRE. Longitudinal microbiota analysis showed that supplementation with L. paracasei CNCM I-3689 was associated with a better recovery of members of the phylum Bacteroidetes. Bile salt analysis and expression analysis of selected host genesrevealed increased level of lithocholate and of ileal expression of camp (human LL-37) upon L. paracasei CNCM I-3689 supplementation. Although a direct effect of L. paracasei CNCM I-3689 on the VRE reduction was not ruled out, our data provide clues to possible anti-VRE mechanisms supporting an indirect anti-VRE effect through the gut microbiota. This work sustains non-antibiotic strategies against opportunistic enterococci after antibiotic-induced dysbiosis.

https://www.ncbi.nlm.nih.gov/pubmed/29572473