儿童血流感染肺炎克雷伯菌毒力与耐药基因分析  

Virulence and drug resistance genes in Klebsiella pneumoniae isolated from children with bloodstream infection

作　　者：鞠启文[1] 王运中[1] 陶云珍[1] 邵雪君[1] 李丹[2] 李阳 JU Qi-wen;WANG Yun-zhong;TAO Yun-zhen;SHAO Xue-jun;LI Dan;LI Yang(Children’s Hospital of Soochow University,Suzhou,Jiangsu 215025,China;不详)

机构地区：[1]苏州大学附属儿童医院检验科,江苏苏州215025 [2]苏州大学附属第二医院检验科,江苏苏州215004

出　　处：《中华医院感染学杂志》2021年第21期3337-3341,共5页Chinese Journal of Nosocomiology

基　　金：国家自然科学基金青年基金资助项目(82002106);江苏省高层次创新创业人才引进计划“双创博士”基金资助项目(2020-30191,2020-30186);江苏省高等学校自然科学研究面上基金资助项目(20KJB310009,20KJB310012);江苏省卫生健康委医学科研面上基金资助项目(M2020027);苏州市科技计划基金资助项目(SYS2020163、SLC201904、SS201867)。

摘　　要：目的探讨儿童血流感染肺炎克雷伯菌毒力和耐药情况。方法收集苏州大学附属儿童医院2017年1月-2019年12月从血流感染患儿血液标本中分离的63株肺炎克雷伯菌作为研究对象,采用全自动质谱仪鉴定菌株,纸片扩散法和全自动细菌鉴定药敏分析仪进行药敏分析,聚合酶链反应(PCR)检测菌株荚膜血清型、毒力基因和β-内酰胺类耐药基因。结果儿童血流感染肺炎克雷伯菌中K57为主要高毒力荚膜血清型,且所有菌株均检出毒力基因,其中53株占比84.13%携带高毒力基因,主要为iroB;其他毒力基因主要为mrkD、wabG、fimH、ycfM和Uge。药敏结果显示,血流感染肺炎克雷伯菌整体耐药率不高,但均检出β-内酰胺类耐药基因,其中超广谱β-内酰胺酶(ESBLs)和AmpC酶基因携带率较高,而碳青霉烯酶基因携带率较低。此外,本研究中有1株为耐碳青霉烯类肺炎克雷伯菌(CRKP),其携带多个β-内酰胺类耐药基因。同时,此CRKP荚膜血清型为K57,且携带高毒力基因iroB,因此为高毒力高耐药肺炎克雷伯菌(CR-HVKP)。结论苏州地区儿童血流感染肺炎克雷伯菌均携带毒力基因,主要为mrkD、wabG、fimH、ycfM、Uge和高毒力基因iroB,其β-内酰胺类抗菌药物耐药机制主要是携带SHV-11、FOX-1、ACT-1等基因。临床分离出1株血流感染CR-HVKP,应引起重视。OBJECTIVE To explore the virulence and drug resistance of Klebsiella pneumoniae isolated from the children with bloodstream infection. METHODS Totally 63 strains of K.pneumoniae that were isolated from blood specimens of the children with bloodstream infection were recruited as the study subjects, the strains were identified by using automatic mass spectrometer, the drug susceptibility testing was performed by disk diffusion method and automatic bacterial identification drug susceptibility analyzer, and the capsular serotypes, virulence genes and β-lactams resistance genes of the strains were detected by means of polymerase chain reaction(PCR). RESULTS K57 was the major hypervirulent capsular serotype among the K.pneumoniae strains, all of the strains were detected with virulence genes, 53(84.13%) carried with hypervirulent genes, among which iroB was dominant, and other major virulence genes included mrkD, wabG, fimH, ycfM and Uge. The result of drug susceptibility testing showed that the overall drug resistance rate of the K.pneumoniae strains causing bloodstream infection was not high, all of the strains were detected with β-lactams drug resistance genes, the carrying rates of extended-spectrum β-lactamases(ESBLs) and AmpC genes were high, however, the carrying rate of carbapenemase genes was low. There was 1 strain of carbapenem-resistant K.pneumoniae(CRKP) which carried with multiple β-lactams resistance genes. The capsular serotype of the CRKP strains was K57, the strain carried with hypervirulent gene iroB, thus it was hypervirulent and highly resistant K.pneumoniae(CR-HVKP). CONCLUSION All of the K.pneumoniae strains isolated from the children with bloodstream infection in Suzhou carry with virulence genes, which are mainly mrkD, wabG, fimH, ycfM, Uge and hypervirulent gene iroB. The carrying with SHV-11,FOX-1 and ACT-1 genes is the major drug resistance mechanisms to β-lactams.

关 键 词：肺炎克雷伯菌 儿童 血流感染 毒力因子 耐药基因 

分 类 号：R378.996[医药卫生—病原生物学]