耐碳青霉烯高毒力肺炎克雷伯菌的临床及分子特点

Clinical and molecular characteristics of carbapenemresistant hypervirulent Klebsiella pneumonia

目的:探讨耐碳青霉烯类高毒力肺炎克雷伯菌(carbapenem-resistant hypervirulent K.pneumoniae,CR-hvKP)感染的临床危险因素和分子流行病学特点,为CR-hvKP菌株的临床预防和治疗提供理论指导。方法:收集徐州医科大学附属医院2017年1月1日至2019年5月31日临床首次分离的CRhvKP菌株,统计相关临床信息,通过质谱进行菌种鉴定,采用VITEK2 Compact全自动细菌分析仪进行药物敏感试验,多位点序列分析(MLST)进行同源分型,PCR法检测常见的碳青霉烯耐药基因(KPC、SME、GES、VIM、IMP、OXA-48)、血清荚膜基因(K1、K2、K5、K20、K54)和毒力基因(rmpA、magA、aerobactin、Iron)。结果:共收集26株耐碳青霉烯高毒力肺炎克雷伯菌,患者多患有基础疾病(高血压、糖尿病等慢性疾病),近期接受过有创性操作或治疗,使用过多种高等级抗菌药物。拉丝实验均为阳性,MLST分型以ST11(73.1%)为主,碳青霉烯基因以KPC-2为主(96.2%),血清荚膜分型以K1和K2为主,主要携带rmpA和aerobactin毒力基因。结论:CR-hvKP同时具有高毒力肺炎克雷伯菌(hypervirulent Klebsiella pneumoniae,hvKP)和耐碳青霉烯类肺炎克雷伯菌(carbapenem-resistant Klebsiella pneumoniae,CRKP)高耐药性、高侵袭性和高传播性的特点,这种细菌感染病情较重,治疗困难,极易造成医院内感染,应及早预防,合理使用抗生素,遵守无菌原则,及时隔离患者,以阻断CR-hvKP在医院内的暴发流行。

Objective:To investigate the clinical risk factors and molecular epidemiological characteristics of carbapenemresistant hypervirulent K.pneumoniae(CR-hvKP)infection,providing theoretical guidance for clinical prevention and treatment of CR-hvKP strains.Methods:The CR-hvKP strain was firstly isolated from the Affiliated Hospital of Xuzhou Medical University from January 1,2017 to May 31,2019.The relevant clinical information was collected,and the strain identification was performed by mass spectrometry.VITEK2 Compact automatic bacteria analyzer was used for drug sensitivity test,multi-site sequence analysis(MLST)for homologous typing,and PCR for common carbapenem resistance genes(KPC,SME,GES,VIM,IMP,OXA-48),serum capsular gene(K1,K2,K5,K20,K54)and virulence genes(rmpA,magA,aerobactin,Iron)detection.Results:A total of 26 carbapenemresistant and highly toxic K.pneumoniae were collected.Most of the patients suffered from underlying diseases(hypertension,diabetes and other chronic diseases).They have recently undergone invasive procedures or treatments and used high-grade antibacterial drugs.The wire drawing experiments were all positive;the MLST classification was mainly ST11(73.1%);carbapenem gene was mainly KPC-2(96.2%);serum capsule type was mainly K1 and K2,mostly carrying rmpA,aerobactin virulence gene.Conclusion:CR-hvKP has the characteristics of both hvKP and CRKP:high drug resistance,high invasiveness and high transmission.This bacterial infection is serious,difficult to treat,and easily causes nosocomial infection.Preventive measures should be taken early,like rational use of antibiotics,adherence to the principle of sterility,and timely isolation of patients to block the outbreak of CR-hvKP in hospitals.