摘要
为了获得具有益生特性的藏羊源海氏肠球菌,试验通过采集健康藏羊肠道内容物,经选择培养基初筛后,进行细菌的分离纯化,利用形态学、生化试验及16S rDNA基因扩增测序对分离菌株进行鉴定,对鉴定得到的菌株进行同源性分析、药敏试验及致病菌抑制能力测定。结果表明:藏羊肠道内容物经细菌分离、筛选,在Pfizer肠球菌选择性培养基上观察到棕黑色菌落,挑取其中一个菌落经革兰氏染色镜检为阳性球菌;分离菌株生化鉴定结果符合肠球菌生化特点,16S rDNA序列与海氏肠球菌基因相似性达100%,综合分析鉴定分离菌株为海氏肠球菌,命名为EH1-ql;分离菌株培养4~12 h为对数生长期,随着细菌的生长,菌液pH值逐渐下降,最终菌液pH值稳定在4.3左右;该分离株具有较好的耐酸性和耐胆盐性,对常见的大部分抗生素敏感,对产气荚膜梭菌抑制能力最强,对金黄色葡萄球菌及大肠杆菌具有一定抑制能力。说明本次从青海藏羊肠道内容物中分离鉴定得到海氏肠球菌,其作为潜在益生菌可为藏羊源益生菌制剂的研究提供候选菌株。
In order to obtain Enterococcus hirae from Tibetan sheep with probiotic properties,the experiment was carried out by collecting the intestinal contents of healthy Tibetan sheep,and after preliminary screening of the selected medium,the bacteria were separated and purified,using morphology,biochemical tests and 16 S rDNA gene amplification and sequencing to identify isolated strains.The identified strains were subjected to homology analysis,drug susceptibility test and determination of pathogenic bacteria inhibition ability.The results showed that the intestinal contents of Tibetan sheep were separated and screened for bacteria;brown-black colonies were observed on the Pfizer Enterococcus selective medium;the colonies were picked and found to be positive cocci by Gram staining microscopy.The biochemical identification results of the isolated strain conformed to the biochemical characteristics of Enterococcus;the 16 S rDNA sequence of the isolated strain had a genetic similarity of 100%with Enterococcus hirae;comprehensive analysis identified the isolated strain as Enterococcus hirae,named EH1-ql.The isolated strain was cultured for 4-12 hours as the logarithmic growth phase;with the growth of the bacteria,the pH value of the bacterial solution gradually decreased,and the final pH value of the bacterial solution stabilized at about 4.3.The isolate had good acid resistance and bile salt tolerance,was sensitive to most common antibiotics,had the most inhibitory ability against Clostridium perfringens and had certain inhibitory ability against Staphylococcus aureus and Escherichia coli.The results suggested that in this study,Enterococcus hirae was isolated and identified from the intestinal contents of Qinghai Tibetan sheep;as a potential probiotic,it could provide a candidate strain for the study of Tibetan sheep-derived probiotic preparation.
作者
贺曦
徐淑琴
马祥兆
陈晓慧
贺晓龙
冶贵生
HE Xi;XU Shuqin;MA Xiangzhao;CHEN Xiaohui;HE Xiaolong;YE Guisheng(Department of Animal Medicine,College of Agriculture and Animal Husbandry,Qinghai University,Xining 810016,China)
出处
《黑龙江畜牧兽医》
CAS
北大核心
2021年第22期63-68,150,共7页
Heilongjiang Animal Science And veterinary Medicine
基金
青海省科技厅项目(2020-ZJ-928)
关键词
藏羊
海氏肠球菌
耐药性
16S
rDNA
分离
鉴定
Tibetan sheep
Enterococcus hirae
drug resistance
16S rDNA
separation
identification
