河南牛无乳链球菌耐药性分析和毒力基因检测

Analysis of Drug Resistance and Virulence Genes of Streptococcus agalactiae from Cattle in Henan

为了解河南牛乳房炎无乳链球菌的耐药性和毒力基因分布状况,本研究对分离鉴定的155株无乳链球菌进行抗生素敏感性试验,并且利用PCR技术检测相关耐药性基因和毒力基因。结果显示:分离株对喹诺酮类敏感度最高,对四环素、氨基糖苷类和大环内酯类表现为极强的耐药性,而对青霉素G的耐药性达到100%;155株分离株检测到突变的青霉素耐药基因pbp2b,此外,aphA-3和aad-6两种氨基糖苷类耐药基因均存在于分离株中,而发现四环素耐药性则主要由tetL,tetM和tetK三种基因介导,检出率分别为25.16%、31.61%和19.35%,同时检测到大环内酯类耐药基因erm(A/T)和ermB基因,检出率为13.55%和50.97%;分离菌中检测到bca、ScpB、hly和rib四种毒力基因,检出率为48.39%、56.77%、20.65%和23.87%。河南地区无乳链球菌携带4种毒力基因以及8种耐药基因,且绝大多数菌株表现出多重耐药性。

In order to investigate the current status of drug resistance and distribution of virulence genes in Streptococcusagalactiae strains in Henan region,155 isolated strains were examined for drug susceptibility,resistance and virulence genes.The results showed that these 155 isolated strains were most susceptible to quinolone but resistant to tetracycline,aminoglycosides and macrolides.Especially,these strains were 100%resistant to penicillin G.The mutant penicillin resistance gene pbp2b were detected in all isolated strains.The aminoglycoside resistant genes aphA-3 and aad-6 were both contributed to the resistance of these strains.The resistance to tetracycline were mediated by tetL,tetM and tetKand their detection rates were 25.16%,31.61%and 19.35%respectively.The macrolide resistant genes erm(A/T)and ermB was also detected and their detection rates were 13.55%and 50.97%,respectively.In addition,the virulence genes bca,ScpB,hlyand rib were also detected in these isolated strains and their detection rates were 48.39%,56.77%,20.65%and 23.87%,respectively.In summary,4 virulence genes and 8 drug resistance genes were distributed in S.agalactiae in Henan region,and multiple resistance genes were also found in most of those strains.