奶牛乳房炎致病菌的分离鉴定及耐药性研究

摘要

In order to undersand microflora distribution of pathogenic bacteria of dairy cow mastitis,as well as path-ogenicity and drug resistance of opportunistic pathogens.302 milk samples of clinical mastitis were collected,from which 257 bacterial strains were isolated and identified by 16 S DNA PCR kit.The tests on mouse pathogenicity and drug resistance were performed for the opportunistic pathogens with high ratios.The results showed that de-tected bacteria could be classified as main pathogens,opportunistic pathogens,lactic acid bacteria and other bacte-ria.Opportunistic pathogens,in which A.pyogenes had obvious pathogennicity in mice,E.faecalis and E.fae-cium did not,but they had certain resistance to antimicrobials.The E.faecalis and E.fecium with a pathogenic condition,belong to lactic acid bacteria that are generally used as probiotics.It showed the pathogenic bacteria of dairy cow mastitis had diversity and complexity.In addition to main pathogens and opportunistic pathogens,some probiotics getting into breast tissue might become opportunistic pathogens to cause mastitis.%为进一步了解奶牛乳房炎致病菌的菌群分布，以及条件致病菌的致病性和耐药性。采集了302份临床型乳房炎乳样，从中分离出257株细菌，使用16 S DNA PCR 试剂盒鉴定分析，对其中检出率较高的条件致病菌进行小鼠致病性和耐药性研究。结果显示，检出菌可分为主要致病菌、条件致病菌、乳酸菌及其他菌。条件致病菌化脓隐秘杆菌对小鼠具有明显的致病性，粪肠球菌和屎肠球菌对小鼠没有明显的致病性，但它们对抗生素均有一定的耐药性。粪肠球菌和屎肠球菌具有条件致病性，但它们属于乳酸菌，而乳酸菌一般作为益生菌使用。说明奶牛乳房炎致病菌具有多样性和复杂性，除了常见的主要致病菌和条件致病菌外，有些益生菌进入乳腺组织也能成为条件致病菌引发乳房炎。