粪便标本中耐碳青霉烯类肠杆菌科细菌的分子生物学与相关的β内酰胺酶特征研究  

Molecular characterization and associatedβ-lactamases of fecal carbapenem-resistant Enterobacteriaceae

作　　者：卢燕芳[1,2] 兰芳俊 陈瑶 李彬[2] LU Yan-fang;LAN Fang-jun;CHEN Yao;LI Bin(Fujian Provincial Maternal and Child Hospital ,Fuzhou,Fujian350001,China)

机构地区：[1]福建省妇幼保健院检验科,福建福州350001 [2]福建医科大学附属协和医院检验科,福建福州350001 [3]福建医科大学,福建福州350001

出　　处：《中华医院感染学杂志》2018年第24期3685-3688,共4页Chinese Journal of Nosocomiology

基　　金：福建省高校杰青基金资助项目(JA13134);福建省卫计委中青年骨干人才培养基金资助项目(2015-ZQN-ZD-15)

摘　　要：目的探讨研究住院患者粪便标本中耐碳青霉烯类肠杆菌科细菌(CRE)的碳青霉烯酶和相关的β-内酰胺酶分子生物学特征。方法收集2011年12月-2012年2月医院临床分离非重复的21株CRE菌株,筛选碳青霉烯酶和相关β-内酰胺酶。采用改良Hodge试验(MHT)对21株CRE进行碳青霉烯酶表型的筛选,采用聚合酶链式反应(PCR)和基因测序法检测21株CRE的碳青霉烯酶和相关β内酰胺酶的耐药基因型。使用接合转移肉汤法进行质粒的接合试验。结果MHT共检出9株碳青霉烯酶阳性菌株,占42.9%;PCR法共检出13株携带CTX-M型ESBLs酶,占61.9%;4株IMP-4阳性的菌株中有3株接合成功,4株KPC-2阳性的菌株中有2株接合成功,菌株KOR1中的NDM-1接合成功。结论医院住院患者肠道分离CRE耐药机制以携带KPC-2和IMP-4为主,且与β-内酰胺酶耐药基因高度相关。医院应该采取严格的感染控制措施,避免CRE在居民卫生保健设施中广泛传播。OBJECTIVE To investigate the molecular biological characteristics of carbapenemase and associatedβ-lactamases of fecal carbapenem-resistant Enterobacteriaceae(CRE)among inpatients.METHODS A total of 21 non-repetitive CRE strains clinically isolated in the hospital between Dec.2011 and Feb.2012 were collected,and screened for the presence of carbapenemases and associatedβ-lactamases.The modified Hodge test was used to detect the carbapenemase production.The potential presence of carbapenemase and associatedβ-lactamase genotypes of the isolates was detected by PCR and gene sequencing.Plasmid conjugation test was carried out using a broth culture mating method.RESULTS MHT detected 9 carbapenemase-positive isolates,accounting for 42.9%.The results of PCR revealed 13(61.9%,21)isolates carried genes encoding CTX-M-type ESBLs enzymes,accounting for 61.9%.Transfer of carbapenem resistance was successful in 3 out of 4 IMP-4-positive strains,2 of4 KPC-2-positive strains.And in vitro transfer of NDM-1 was successful for the strain KOR1.CONCLUSION The resistance mechanism of CRE isolated from intestinal carriage in inpatients is dominated by KPC-2 and IMP-4,and is highly correlated withβ-lactamase resistance genes.Hospitals should adopt strict infection control measures to avoid the transmission of CRE in residents’ health care facilities.

关 键 词：粪便携带 碳青霉烯酶 Β-内酰胺酶 肠杆菌科细菌 

分 类 号：R446.5[医药卫生—诊断学]