产ESBLs肺炎克雷伯菌ESBLs基因与可移动遗传元件相关性分析

目的了解产超广谱β-内酰胺酶(extended spectrum beta-lactamases,ESBLs)肺炎克雷伯菌(Klebsiella pnewmoniae,Kpn)ESBLs基因与可移动遗传元件(mobile genetic elements,MGEs)标记基因的携带情况及其相关性。方法收集从住院患者标本中分离出的产与非产ESBLsKpn非重复菌株各100株,采用PCR检测细菌中4种ESBLs基因与8种MGEs标记基因,并作指标聚类分析。结果产ESBLs Kpm中,ESBLs基因阳性率高达100%;MGEs标记基因以IS26、ISEcpl、trad、trbC和intll基因为主,阳性率高于非产ESBLsKpn(P-0.05);ESBLs基因与MGEs标记基因的同时检出率明显高于非产ESBLs Kpn(P-0.05):基因blaSHV-12、blaOXA-1与MGEs基因tmpU、np513、mer4、intll/相关联,基因blaTEM-1、bldCTX-M-125与MGEs基因ISEcp1、IS26、trad相关联。产与非产ESBLs Kpn均没有只检出MGEs标记基因的菌株。结论产ESBLsKpn ESBLs基因和MGEs标记基因携带率高,两者存在相关性,可能是产ESBLsKpn出现多重耐药的重要原因;MGEs标记基因在Kpn中可能不是单独存在的。

Correlation analysis between ESBLs genes and mobile genetic elements in ESBLs-producing Klebsiella pneumoniae

Objective To investigate the distribution status of ESBLs genes and genetic markers of MGEs in ESBLs-producing Klebsiella pneumoniae and observe their correlation. Methods 100 Non-repetitive ESBLs-producing Klebsiella pneumoniae strains and 100 non-repetitive non-ESBLs-producing Klebsiella pneumoniae strains were collected from hospitalized patients. Four ESBLs genes and eight genetic markers of MGEs were analyzed by PCR . Then the test results were analyzed using the index cluster analysis. Results The positive rates of ESBLs genes were as high as 100% in ESBLs-producing Klebsiella pneumoniae. The main genotypes of genetic markers of MGEs were IS26, ISEcp1, traA, trbC, and intI1. Their positive rates in ESBLs-producing Klebsiella pneumoniae were higher than those in non-ESBLs-producing Klebsiella pneumoniae (P<0.05). The detection rates of ESBLs genes and genetic markers of MGEs in ESBLs-producing Klebsiella pneumoniae were significantly higher than those in non-ESBLs-producing Klebsiella pneumoniae (P<0.05). There was an association between blaSHV-12, blaOXA-1, and tnpU, tnp513, merA, intI1. There was also an association between blaTEM-1, blaCTX-M-125, and ISEcp1, IS26, traA. No strain only carrying genetic markers of MGEs was detected in both ESBLs-producing Klebsiella pneumoniae and non-ESBLs-producing Klebsiella pneumoniae. Conclusion The carrying rates of ESBLs genes and genetic markers of MGEs in ESBLs-producing Klebsiella pneumoniae were high. The ESBLs genes carried by ESBLs-producing Klebsiella pneumoniae was associated with genetic markers of MGEs, which probably played a key role in multidrug resistance for ESBLs-producing Klebsiella pneumoniae. The genetic markers of MGEs might not exist alone in Klebsiella