携带噁唑烷酮耐药基因optrA藏羊源产气荚膜梭菌的检测

Detection of Tibetan Sheep Clostridium perfringens Isolate Harboring Oxazolidinones Resistance Gene OptrA

对1株携带有噁唑烷酮类耐药基因oprA的藏羊产气荚膜梭菌QHY-2进行了形态学观察、毒素分型、全基因组测序分析和oprA基因环境分析。结果显示,QHY-2为A型产气荚膜梭菌,对磺胺异噁唑、四环素、氟苯尼考、利奈唑胺和氯霉素等药物具有较强抵抗力。除携带有cpa、pfoA、colA、cloSI、nagH等毒素基因外,还携带有tetA(P)、tet(44)、fexA、optrA、ant(6)-Ib、aac(6′)-aph(2″)、erm(A)、erm(B)和erm(Q)等9种耐药基因。QHY-2的optrA基因环境分析显示,其上、下游分别为耐药基因fexA和erm(A),并与多个参考质粒携带的optrA基因高度相似。首次在藏羊产气荚膜梭菌发现噁唑烷酮类耐药基因oprA,对动物源产气荚膜梭菌的耐药性及噁唑烷酮类药物耐药基因传播趋势评估具有参考价值。

To study the antimicrobial-resistance and spread of antimicrobial resistant genes in Clostridium perfringens,we performed morphological observation,toxin typing,whole genome sequencing(WGS)and gene-environment analysis of oprA on one Tibetan sheep C.perfringens isolate QHY-2,which carried oxazolidinones resistance gene optrA.We found QHY-2 belongs to C.perfringens type A,and it has strong resistance against sulfaisoxazole,tetracycline,florfenicol,linezolid and chloramphenicol,etc.After WGS,1l toxin genes such as cpa,pfoA,colA,cloSI,nagH and 9 antimicrobial-resistance genes-tetA(P),tet(44),fexA,optrA,ant(6)-Ib,aac(6')-aph(2"),erm(A),erm(B),erm(Q)were detected in QHY-2,and antimicrobial-resistance genes feaA and erm(A)were found in the upstream and downstream of optrA,respectively.Moreover,the gene-environment of optrA in QHY-2 was similar with the reference plasmid sequences.This is the first report of oxazolidinones resistance gene optrA in Tibetab sheep C.perfringens,which has reference significance for the antimicrobial-resistance of animal C.perfringens and spreading trend of oxazolidinones-resistant genes.