【作者】 魏鲁予；

【导师】 剡根强；

【作者基本信息】 石河子大学 ， 预防兽医学， 2010， 硕士

【摘要】 本研究从新疆北疆地区部分奶牛场临床型奶牛乳房炎乳样中分离的65株木糖葡萄球菌,采用常规生理生化鉴定、梅里埃生化鉴定系统鉴定和木糖葡萄球菌16SrRNA分子生物学鉴定筛选出60株木糖葡萄球菌,对分离的木糖葡萄球菌进行了致病性试验,药敏试验,及木糖葡萄球菌携带的I类整合子的PCR检测,分析了木糖葡萄球菌耐药表型与所携带的I类整合子之间的相关性。结果如下：1.被测菌株血浆凝固酶均为阴性,耐热核酸酶阴性,过氧化氢酶及甘露醇发酵为阳性,8株分离菌出现β-溶血,5株对小白鼠有致病性。2.对筛选出的木糖葡萄球菌进行16SrRNA基因PCR检测,有60株扩增出与目的片段相同的片段,选取典型的片段回收测序,经测序,在NCBI中比对,同源性在98.97%以上。3.木糖葡萄球菌耐药率较高的抗生素包括磺胺嘧啶钠(100%),青霉素钾(93.3%)、庆大霉素(90%)、四环素(90%)、硫酸链霉素(86.7%),敏感度较高的为阿米卡星(6.7%)、恩诺沙星(10%)。试验菌主要对氨基糖苷类,青霉素类,四环素类,磺胺类抗生素表现耐药性。4.本研究对新疆北疆地区分离的木糖葡萄球菌I类整合酶基因及其耐药基因盒进行了检测,分析了菌株携带整合子与其耐药表型的相关性,结果发现,I类整合子阳性菌株的耐药率明显高于阴性菌株,药敏表型分析表明,I类整合子与木糖葡萄球菌的耐药性有关,即I类整合子阳性菌比I类整合子阴性菌更容易产生耐药性。通过对整合子系统的研究,可以更多的了解细菌的耐药机制。更多还原

【Abstract】 This study take part dairy farm clinical mastitis isolated Staphylococcus xylose 65 strain from north of xinjiang, taking convention Physiological and biochemical identification method, API identification, and molecular biology identification sieve 60 strain Staphylococcus xylose.This experiment take pathogenicity experiment, resistant experiment and carry the PCR detection of class I integron, analysis dependability of integron to resistant phenotypic. Consequence:1.The tested strains are staphylocoagulase negative, Heat-resistant nuclease-negative, Catalase and mannitol fermentation positive.8 bacteral strain haveβhemolysis,5 bacteral strain have pathogenicity.2.16SrRNA gene PCR for detection of Staphylococcus xylose,60 strains had been amplificated the same fragment. I had selected typical fragment reclaim, sequence, comparison by ncbi,homology 98.97%.3. The drug sensitivity tests showed that resistant to Sulfadiazine Sodium (drag fast rate 100%),benzylpenicillin potassium (drag fast rate 93.3%), Tetracycline (drag fast rate 90.0%), Gentamicin (drag fast rate 90.0%), streptomycin sulfate (drag fast rate 86.7%), sensitive to Amikacin (drag fast rate 6.7%), Enrofloxac (drag fast rate 10.0%). Experiment strains main drug fast to aminoglycosides, penicillins, sulfamido appearance hadro-resistant.4. This research has detected Staphylococcus xylose class I integrase gene and resistant cassettes from north-territory strain, Analysis of strains carrying integrons and antimicrobial resistance phenotype correlation. Consequence, class I integron-positive strains of resistant strains was significantly higher than negative, susceptibility test discovery, class I integron have correlation to Staphylococcus xylose resistance. Class I integron positive strain facility form resistance to negative strain. Through integron system research, it can comprehend bacterium resistant mechanism.更多还原