摘要
从我国吉林地区患有肺炎的病猪分离到优势菌株,对分离菌株进行16S rRNA鉴定,确定为副猪链球菌(Streptococcus parasuis,S.parasuis),命名为 WYF-8B.药敏纸片扩散法检测结果显示,WYF-8B对杆菌肽、磺胺间甲氧苄啶、林可霉素、红霉素、磷霉素、阿奇霉素、青霉素、多西环素、复方新诺明、磺胺异恶唑、环丙沙星、恩诺沙星、四环素、苯唑西林、庆大霉素、头孢唑林、氨苄西林均耐药;对氟苯尼考,氯霉素高度敏感.生化鉴定结果显示,WYF-8B可发酵水杨酸、麦芽糖、乳糖、蔗糖、七叶苷、葡萄糖;不发酵甘露醇、尿素、棉子糖、木糖、阿拉伯糖、山梨醇.利用第二代全基因组测序技术对WYF-8B耐药基因型进行研究,结果发现其携带对大环内酯类抗生素的抗性基因Mef(E)、ErmB,对β-内酰胺类抗生素的抗性基因pbp2b、pbp1a、pbp2x,对氟喹诺酮类抗生素的抗性基因gyrA、parC、gvlB,对氨基糖苷类抗生素的抗性基因ANT(6)-Ia、AAC(6')-Ie-APH(2")-Ia、ANT(9)-Ia、APH(3')-Ⅲ a,对林可酰胺类抗生素的抗性基lnuB、lmrC、lmrD,对四环素类抗生素的抗性基因tetM,对杆菌肽的抗性基因bcrA,结果显示耐药表型与测序结果的耐药基因型相符.WYF-8B毒力因子研究结果显示,WYF-8B共携带13个毒力因子(pavA、fbp54、clpP、cps4I、wbtB、cpsI、tufA、galE、hasC、groEL、wbtL、gndA、wbtF),其作用机制主要为促进细菌的扩散、转移、定居、抗吞噬及不被宿主免疫细胞识别等.药物敏感试验结果为研究副猪链球菌的临床用药提供参考,耐药表型与毒力因子为新型药物及疫苗的研发奠定基础.
Abstract
Streptococcus parasuis(S.parasuis)is a close relative of S.suis and can cause meningi-tis,pneumonia or systemic symptoms in affected animals.In this paper,the dominant strain was i-solated from diseased pigs with pneumonia in Jilin,China,and the isolated strain was identified as S.parasuis by 16S rRNA,it was named WYF-8B.Resistance was tested by the susceptibility tablet diffusion method,and WYF-8B was resistant to bacitracin,sulfamethoxoprim,lincomycin,erythro-mycin,fosfamycin,azithromycin,penicillin,doxycycline,cotrimotrixazole,sulfamisoxazole,cipro-floxacin,enrofloxacin,tetracycline,benzoxacillin,gentamicin,efazolin,and ampicillin.It was highly sensitive to florfenicol,chloramphenicol.Iochemical identification revealed that WYF-8B could fer-ment salicylic acid,maltose,lactose,sucrose,oxaesin,and glucose;nonfermentable mannitol,urea,raffinose,xylose,arabinose,and sorbitol.Using the second-generation whole-genome sequencing technology to study the WYF-8B resistant genotype,it was found that it carried the macrolide anti-biotic resistance genes Mef(E)and ErmB;resistance genes pbp2b,pbp1a,and pbp2x to β-lactam antibiotics;resistance genes gyrA,parC,and grlB to fluoroquinolones;resistance genes ANT(6)-Ia,AAC(6')-Ie-APH(2')-Ia,ANT(9)-Ia,APH(3')-Ⅲa to aminoglycoside antibiotics;re-sistance groups lnuB,lmrC,lmrD against lincomide antibiotics;resistance gene tetM to tetracy-cline antibiotics;the resistance gene of bacitracin,bcrA.The results found that the resistance phe-notype matches the resistance genotype of the sequencing results.The study of WYF-8B virulence factors found that WYF-8B carried 13 virulence factors(pavA,fbp 54,clpP,cps 4,cps 4 I,wbtB,cps,sI,tufA,galE,hasC,groEL,wrbtL,wbbtF),which mainly acted to promote bacterial diffu-sion,transfer,settlement,antiphagocytosis and immune evasion.The results of drug sensitivity test provide a reference for the study of clinical medication of S.parasuis,and drug resistance pheno-type and virulence factors lay the foundation for the research and development of new drugs and vaccines.
基金项目
吉林省科技创新平台资助项目(YDZJ202302CXJD038)
维普
万方数据