摘要
基于细菌rRNA区域序列的PCR技术,通过设计特异性引物从奶样中快速、准确地鉴定奶牛乳房炎主要致病菌金黄色葡萄球菌。采用金黄色葡萄球菌与挤奶前从奶牛乳房上洗刷下来的污水经过3次富集的方法,通过双层琼脂平板法,分离纯化得到了强裂解性的奶牛乳房炎主要致病菌金黄色葡萄球菌的噬菌体。本试验分离的是可收缩尾的噬菌体,其头部为二十面体,约50 nm×62.5 nm,尾部长约187.5 nm,尾宽约37.5 nm,有尾鞘、基板等结构。纯化后在双层琼脂平板上形成的噬菌斑大而整齐,边缘光滑,透明,直径约2 mm,具有明显的强裂解性噬菌体特性,通过测定,该噬菌体的最佳感染复数为0.01,效价大于109PFU/mL。对噬菌体的不同保存方法进行比较,结果表明,将噬菌体置于-80℃加入7%DMSO冷藏是较好的保存方法。
Based on the molecular tools to identify with rapidity,sensitivity,and specificity the major pathogens involved in intramammary infections in cows,a PCR-based assays of the highly divergent and species-specific regions of the DNA coding for 23S rRNA was employed.In this study,a novel virulent bacteriophage had been isolated from the waste water sample in a local dairy farm after three times enrichment in LB liquid medium co-cultured with S.aureus isolates.TEM observation of the isolated phage had an icosahedral capsid of 62.5 nm in diameter and a long（187.5 nm） with contractible tail,there was a connector linked the head and tail.As a tailed virus of bacteria,phage classified into the families of tailed viruses infected bacteria.The plaques of the phage were formed transparent uniformed,clear,round zones and their sizes were 2 mm in diameter.The titer of phage against S.aureus isolates was more than 109 PFU/mL.Storage conditions of the phage were studied.The phage should store at-80 ℃ supplemented with 7% DMSO.
出处
《中国畜牧兽医》
CAS
北大核心
2011年第6期141-146,共6页
China Animal Husbandry & Veterinary Medicine
基金
陕西省"13115"科技创新重大专项(2009ZDKG-18)
