KL47型和KL64型ST11碳青霉烯类耐药肺炎克雷伯菌分子流行病学特征

Molecular epidemiological characteristics of ST11-KL47 and ST11-KL64 carbapenem-resistant Klebsiella pneumoniae

目的 探究KL47型和KL64型ST11碳青霉烯类耐药肺炎克雷伯菌(CRKP)分子流行病学特征。方法 收集2018年12月-2019年6月徐州医科大学附属医院87株非重复CRKP菌株,通过多位点序列分型技术确定菌株分型,最终纳入62株ST11型CRKP进行研究。基于wzi基因测序将62株CRKP分为KL47和KL64两组。PCR检测5种常见的碳青霉烯酶基因(KPC、NDM、VIM、IMP、OXA-48)、6种超广谱β内酰胺酶基因(ESBL)(SHV、TEM、CTX-M1、CTX-M2、CTX-M8、CTX-M9)和8个毒力基因(rmpA、rmpA2、iucA、iroN、entB、ybtS、fimH、mrkD),统计分析比较ST11-KL47型菌株和ST11-KL64型菌株在耐药和毒力基因携带模式上的差别。结果 38株为ST11-KL47型菌株,24株为ST11-KL64型菌株。所有菌株均为多药耐药菌,对β内酰胺类、喹诺酮类抗菌药物表现为100.00%耐药,对磺胺甲噁唑/甲氧苄啶和阿米卡星耐药率均高于50%,对多黏菌素和替加环素完全敏感。两组菌株药敏结果无统计学差异。ST11型菌株均产KPC-2酶,携带的ESBL基因均以bla检出率最高。对于基因bla,ST11-KL47型菌株以携带bla为主,ST11-KL64型菌株主要携带bla。ST11-KL64型菌株rmpA的检出率高于ST11-KL47菌株(P<0.05)。结论 本地区CRKP多为ST11型多药耐药菌,且ST11-KL64型肺炎克雷伯菌相比ST11-KL47型肺炎克雷伯菌携带更多的毒力基因和耐药基因,应合理使用抗菌药物并加强医院感染防控措施。

OBJECTIVE To explore the molecular epidemiological characteristics of ST11-KL47 and ST11-KL64 carbapenem-resistant Klebsiella pneumoniae(CRKP). METHODS Totally 87 strains of non-repetitive CRKP were collected from The Affiliated Hospital of Xuzhou Medical University from Dec 2018 to Jun 2019, the types of the strains were determined by multilocus sequence typing technology, and 62 strains of ST11 CRKP were finally included. The 62 strains were divided into the KL47 group and KL64 group based on the wzi sequencing, the 5 types of common carbapenemase genes(KPC, NDM, VIM, IMP, OXA-48), 6 types of extend-spectrum β-latamase(ESBL) genes( SHV, TEM, CTX-M1, CTX-M2, CTX-M8, CTX-M9) and 8 virulence genes(rmpA, rmpA2, iucA, iroN, entB, ybtS, fimH, mrkD) were detected by PCR. The modes of carrying with drug resistance genes and virulence genes were statistically analyzed and compared between the ST11-KL47 strains and the ST11-KL64 strains. RESULTS There were 38 strains of ST11-KL47 and 24 strains of ST11-KL64. All of the strains of multidrug-resistant, and the drug resistance rates to β-lactams and quinolones were 100.00%, the drug resistance rates to sulfamethoxazole-trimethoprim and amikacin were more than 50%, and the strains were completely sensitive to polymyxin and tigecycline. There was no significant difference in the result of drug susceptibility testing between the two groups. All of the ST11 strains produced KPC-2 enzyme, the detection rate of blawas the highest among the ESBL genes. blawas dominant among the ST11-KL47 carrying with blagenes, and blawas dominant among the ST11-KL64 strains. The detection rate of rmpA was significantly higher in the ST11-KL64 strains than in the ST11-KL47 strains(P<0.05). CONCLUSION ST11 multidrug-resistant bacteria are dominant among the CRKP strains, and the ST11-KL64 K.pneumoniae strains carry with more virulence genes and drug resistance genes than the ST1-KL47 K.pneumoniae strains. It is necessary to reasonably use antibiotics and take prevention measures.