牛乳中产色葡萄球菌的分离与鉴定

费育超 倪宏波

摘要 [目的]确定送检的患乳房炎病牛乳汁中是否有产色葡萄球菌感染。[方法]从患乳房炎病牛乳汁中分离致病菌，并对其进行鉴定，最后通过药敏试验筛选出对其敏感的药物。[结果]分离菌16S rRNA基因片段为长度1 422 bp的核苷酸序列。经BLAST分析可知，其与产色葡萄球菌16S rRNA核苷酸序列相似性高达99%，确定其为产色葡萄球菌。药敏试验结果表明，产色葡萄球菌对环丙沙星和四环素高度敏感，而对多黏菌素-B、青霉素、克林霉素和诺氟沙星等不敏感。[结论]研究结果可为确定乳房炎的病原及治疗方法提供新思路。

关键词 奶牛乳房炎；16S rRNA；产色葡萄球菌；耐药性分析

中图分类号 S852.61 文献标识码 A 文章编号 0517-6611（2017）25-0120-02

Abstract [Objective]To check whether there was Staphylococcus chromogenes infection in the milk of diseased cattle with mastitis.[Method]Pathogen were isolated and identified from the milk of diseased cattle with mastitis.And the sensitive drugs were screened out by drug susceptibility test.[Result] 16S rRNA gene fragment of the isolated bacteria was a nucleotide sequence with the length of 1 422 bp.BLAST analysis showed that its similarity with Staphylococcus chromogenes 16S rRNA nucleotide sequence was up to 99%，so it was confirmed as Staphylococcus chromogenes.Drug sensitivity test showed that it was highly sensitive to ciprofloxacin and tetracycline，and it was tolerant to polymyxinB，penicillin，clindamycin and norfloxacin and others.[Conclusion]The research results can provide new ideas for studying the pathogen and treatment methods of mastitis.

Key words Cow mastitis；16S rRNA；Staphylococcus chromogenes；Drug tolerance analysis

奶牛乳房炎是对乳品业危害最严重的疾病之一[1]。葡萄球菌是奶牛乳房炎发生的主要致病菌，分为凝固酶阳性葡萄球菌（Coagulase positive staphylococcus，CPS）和凝固酶阴性葡萄球菌（Coagulase negative staphylococcus，CNS）。产色葡萄球菌属于CNS，是一种重要的条件性致病菌和免疫损伤时的感染菌，发生感染时往往不表现典型的临床症状，但是当机体抵抗力降低或其进入非正常寄居部位时，可引起多种感染[2]。产色葡萄球菌常常定殖于乳头且易在乳导管内增殖，会导致临床型和隐性型乳房炎，头胎牛比多胎牛更易感，感染后发展成临床型乳房炎。近年来，产色葡萄球菌已成为临床感染的重要病原菌，已经在牛乳[3]、鸡和羊中分离到，并能产生毒素[4-5]，造成危害。随着广谱抗生素的长期不合理使用，葡萄球菌的耐药性日益严重，特别是抗甲氧西林葡萄球菌的出现，多重耐药性的特点使其成为临床疾病治疗上最棘手的问题之一。……