内蒙古部分地区致奶牛乳房炎金黄色葡萄球菌和产色葡萄球菌的分子流行病学及耐药性研究

摘要

To investigate the epidemiology and drug resistance of the Staphylococcus aureus and Staphylococcus chromogenes from dairy cattle in some regions of Inner Mongolia,the two kinds of Staphylococcus spp were isolated from 330 cow mastitis samples collected in three large-scale dairy farms in the regions and subjected to examination of the antimicrobial resistance profiles,druge resistant genes and DNA fingerprint,and the isolates of S.aureus were further characterized by multilocus sequence typing (MLST).The results shown that 14 (4.24％) S.aureus and 23 (6.97％) S.chromogenes were isolated,which were classified into 8 and 16 different pulsed-field gel electrophoresis (PFGE) pattems for S.aureus and S.chromogenes,respectively.These isolates showed high resistant rates to lincomycin (66.67％),penicillin (66.7％),oxacillin(37.5％) and erythromycin (25％).The positive rates of the resistance genes were blaZ (54.17％),lnu(A) (33.33％) and erm(B) (20.83％),respectively.%为调查奶牛乳房炎中金黄色葡萄球菌和产色葡萄球菌的流行病学和耐药性情况,本研究对采集自内蒙古部分地区3个规模化奶牛场的330份奶样进行了葡萄球菌的分离、鉴定、耐药表型分析及基因型的检测;采用脉冲场凝胶电泳(PFGE)方法对分离株进行了亲缘性分析,多位点序列分型(MLST)法对金黄色葡萄球菌进行了基因分型分析.结果表明,从330份奶样共分离到14株金黄色葡萄球菌和23株产色葡萄球菌,两者的分离率分别为4.24％(14/330)和6.97％(23/330);PFGE分型共获得8种不同谱型的金黄色葡萄球菌和16种不同谱型的产色葡萄球菌,表明这些分离株中存在克隆传播现象;药敏试验结果显示,两种病原菌对林可霉素、青霉素、苯唑西林和红霉素耐药率较高,分别为66.67％(16/24)、66.67％(16/24)、37.5％(9/24))和25％(6/24);介导青霉素耐药的blaZ基因检出率最高,为54.17％(13/24),其次为介导林可霉素和红霉素耐药的Inu (A)和erm (B)基因,其检出率分别为33.33％(8/24)和20.83％(5/24).本研究结果为控制该地区奶牛乳房炎的传播、蔓延及临床用药提供了实验依据.