内蒙古地区犊牛源金黄色葡萄球菌的耐药性分析及毒力基因检测

Drug resistance analysis and virulence gene detection of calf-derived Staphylococcus aureus in Inner Mongolia Autonomous Region

为了了解内蒙古地区犊牛源金黄色葡萄球菌的耐药表型、耐药基因及毒力基因的流行情况,试验对采集的104份犊牛病料(鼻拭子37份、口腔拭子13份、粪便样本54份)进行犊牛源金黄色葡萄球菌的分离纯化、生化鉴定及分子生物学鉴定,并对分离的犊牛源金黄色葡萄球菌菌株进行药敏试验、耐药基因及毒力基因检测。结果表明:通过对犊牛病料进行分离培养及生化鉴定,得到43株革兰氏阳性球菌,初步判定分离菌为犊牛源金黄色葡萄球菌,分离率为41.3%。43株分离株16S rDNA基因PCR扩增得到1 505 bp大小的目的条带,与预期结果相符。分离株对氨苄西林、头孢西丁、复方新诺明、卡那霉素等药物耐药,耐药率分别为100%、90.7%、81.4%、60.5%;对环丙沙星的耐药率最低,耐药率为9.3%。耐药基因中blaZ基因的检出率最高,为90.7%;norA与norB基因检出率相同,均为81.4%;ermA基因检出率为30.2%;ermB基因检出率为39.5%;emrC基因检出率为14.0%;Sul1基因检出率为53.5%;同时携带7种耐药基因的检出率为4.7%。毒力基因中hla基因的检出率最高,为58.1%;hlb基因检出率为27.9%;pvl基因检出率为18.6%;其余毒力基因未被检出。说明内蒙古地区犊牛源金黄色葡萄球菌耐药性比较严重,携带多重耐药基因,并携带hla、hlb、pvl毒力基因,建议临床上根据药敏试验结果科学合理地选择抗菌药物,有效做好疫病防控。

In order to understand the prevalence of the resistance phenotype,resistance genes,and virulence genes of calve-derived Staphylococcus aureus in Inner Mongolia Autonomous Region,in this experiment,104 calf samples(37 nasal swabs,13 oral swabs,and 54 fecal samples) were collected for the isolation and purification,biochemical identification,and molecular biological identification of calve-derived Staphylococcus aureus.Drug sensitivity test,drug resistance gene detection and virulence gene detection were carried out on the isolated calve-derived Staphylococcus aureus.The results showed that through isolation,cultivation,and biochemical identification of calf samples,43 strains of Gram positive cocci were obtained,which were preliminarily determined as calve-derived Staphylococcus aureus,with a separation rate of 41.3%.PCR amplification of the 16S rDNA gene from 43 isolated strains yielded a 1 505 bp target band,which was consistent with the expected results.The isolates were resistant to ampicillin,cefoxitin,compound sulfamethoxazole,kanamycin,and the drug resistance rates were 100%,90.7%,81.4% and 60.5% respectively,with the lowest resistance rate to ciprofloxacin,which was 9.3%.Among the resistance genes,the detection rate of blaZ gene was the most,90.7%;the detection rates of norA and norB genes were the same,both 81.4%;the detection rate of ermA gene was 30.2%;the detection rate of ermB gene was 39.5%;the detection rate of emrC gene was 14.0%;the detection rate of Sul1 gene was 53.5%;the detection rate of carrying 7 resistance genes was 4.7%.The highest detection rate of hla gene in virulence genes was the highest,58.1%;the detection rate of hlb gene was 27.9%;the detection rate of pvl gene was 18.6%,and the remaining virulence genes were not detected.The results indicated that the resistance of calve-derived Staphylococcus aureus in Inner Mongolia Autonomous Region was severe,carrying multiple resistance genes,as well as hla,hlb,and pvl virulence genes.It was recommended to scientifically and reasonably select antibiotics based on drug sensitivity test results in clinical practice to effectively prevent and control the epidemic.