猪肠道大肠杆菌噬菌体对产肠毒素大肠杆菌的抑菌作用  

Study on the Bacteriostatic Effect of Porcine Coliphages on Enterotoxigenic Escherichia coli

作　　者：周贝 林焱[1] 朱伟云[1] ZHOU Bei;LIN Yan;ZHU Weiyun(National Center for International Research on Animal Gut Nutrition,Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health,Laboratory of Gastrointestinal Microbiology,Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]国家动物消化道营养国际联合研究中心,江苏省消化道营养与动物健康重点实验室,南京农业大学消化道微生物研究室,南京210095

出　　处：《畜牧兽医学报》2020年第7期1748-1755,共8页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：国家自然科学基金青年基金(31802102);中央高校基本业务费(KJQN201936)。

摘　　要：此前本实验室从健康猪肠道及粪样中分离纯化得到57株大肠杆菌噬菌体,发现其中有12株噬菌体可裂解产肠毒素大肠杆菌(ETEC),本研究旨在探究这些大肠杆菌噬菌体的宿主谱及抑菌效力,以期了解肠道内大肠杆菌噬菌体对机体的保护作用。以89株大肠杆菌为宿主菌(其中包括5株ETEC),采用点滴法、双层平板法和液体扩增法测定噬菌体的宿主谱,利用浊度法测定噬菌体对ETEC的抑菌效力,并对噬菌体分类进行鉴定。12株噬菌体均能裂解一种或多种ETEC,但是均无法通过感染ETEC而增殖。S143_1、S143_2、S144_2、S35、S86_1、L86及S172等7株噬菌体虽然无法通过ETEC产生子代噬菌体,但在感染复数(MOI)为10或100时仍对ETEC具有显著的抑菌效力。12株噬菌体中有8株为T4样噬菌体,其他4株噬菌体均属于有尾噬菌体目肌尾噬菌体科。本研究从猪肠道内分离到12株大肠杆菌噬菌体,虽然无法感染ETEC,但仍可裂解ETEC,其中,7株在MOI为10或100时可有效地抑制ETEC生长。Previously 57 Escherichia coli phages were isolated and identified from the intestines of healthy pigs,and 12 of them were found to lyse enterotoxigenic Escherichia coli(ETEC).To gain a deep insight of the protective effect of the 12 coliphages on the animal hosts,we determined the host range and bacteriostatic efficacy of the 12 coliphages.89 E.coli strains(including five ETEC strains)isolated from pig feces previously were used as indicator strains for host spectrum determination.The host range of coliphages was conducted by the spot test method,double-layer agar plate method and liqud LB culture.Bacteriostatic ability of coliphages on ETEC was evaluated by turbidity measurement.The results showed that all the 12 coliphages could lyse one or more ETEC strains,however,none could produce progeny by infecting ETEC.Nevertheless,seven coliphages(S143_1,S143_2,S144_2,S35,S86_1,L86 and S172)could significantly inhibit the growth of ETEC at MOI of 10 or 100.TEM observation revealed that 8 of the 12 coliphages were T4-like coliphages and the other four belonged to Myoviridae.These results suggest that the coliphages isolated from porcine gut which could not infect ETEC but lyse ETEC still inhibit growth of ETEC.

关 键 词：大肠杆菌噬菌体 宿主谱 产肠毒素大肠杆菌 抑菌效力 

分 类 号：Q939.48[生物学—微生物学]