Gut Microbiology & Immunology Group, Chemistry of Natural & Microbial Products Department, Pharmaceutical Industries Research Division, National Research Centre, 33 El Buhouth St., Dokki, Cairo, 12622, Egypt.
Department of Microbiology & Immunology, Faculty of Pharmacy, Ain Shams University, African Union Organization St., Abbassia, Cairo, 11566, Egypt.
Probiotics Antimicrob Proteins. 2018 Sep;10(3):511-522. doi: 10.1007/s12602-017-9285-7.
This study is aimed at the isolation, identification, and characterization of potential probiotic strains capable of inhibiting Clostridium difficile in vitro and in vivo. Twenty isolates were isolated from infant fecal samples and screened against C. difficile using their cell-free supernatant. Only three isolates showed maximum inhibition from 56.05 to 60.60%, thus they were characterized for probiotic properties and safety. The results obtained approved their tolerance to the gastrointestinal tract conditions and safety profile. They were identified by sequencing 16S rRNA as Enterococcus faecalis NM815, E. faecalis NM915, and Enterococcus faecium NM1015. For in vivo evaluation, a viable mixture of these three strains (10 CFU/mL) was administrated to a group of mice (treated group) in daily dose for 14 days, then followed by challenge with viable C. difficile (10 CFU/mL) in daily dose for 7 days, then a second administration of a viable mixture of the three strains was done daily for 7 days. In addition, the control group was administered PBS buffer only and the untreated group received PBS buffer instead of the probiotic mixture before and after the challenge with C. difficile. The results obtained from histological analysis confirmed the effectiveness of our three potential probiotic strains which expressed inhibition of C. difficile and maintained the structural integrity of the liver and intestinal cells.
本研究旨在分离、鉴定和表征能够在体外和体内抑制艰难梭菌的潜在益生菌株。从婴儿粪便样本中分离出 20 株，并使用其无细胞上清液筛选出对艰难梭菌的抑制作用。只有 3 株显示出最大的抑制作用，抑制率为 56.05%至 60.60%，因此对其进行了益生菌特性和安全性的特征描述。获得的结果证实了它们对胃肠道条件的耐受性和安全性。通过测序 16S rRNA 将它们鉴定为粪肠球菌 NM815、粪肠球菌 NM915 和屎肠球菌 NM1015。为了进行体内评价，将这三种菌株（10 CFU/mL）的活菌混合物以每日剂量给予一组小鼠（处理组），持续 14 天，然后用 10 CFU/mL 的活菌艰难梭菌进行每日剂量挑战，持续 7 天，然后再次每日给予三种菌株的活菌混合物，持续 7 天。此外，对照组仅给予 PBS 缓冲液，未处理组在接受 PBS 缓冲液代替益生菌混合物之前和之后接受 PBS 缓冲液代替益生菌混合物。组织学分析的结果证实了我们的三种潜在益生菌株的有效性，它们表达了对艰难梭菌的抑制作用，并保持了肝和肠细胞的结构完整性。
