阴沟肠杆菌产碳青霉烯酶的基因型与临床感染的特征分析  

Study on genotype and clinical characteristics of infection of carbapenemase-producing Enterobacter cloacae

作　　者：赵岐刚 贾秀芹[2] 庞峰[1] 李艳华[1] 

机构地区：[1]山东省聊城市人民医院检验科,252000 [2]山东省聊城市人民医院药学部临床药学室,252000

出　　处：《中华医学杂志》2015年第40期3264-3268,共5页National Medical Journal of China

基　　金：山东省自然科学基金（ZR2014HL090）

摘　　要：目的 了解医院产碳青霉烯酶阴沟肠杆菌的主要基因型,并对其临床感染特征进行分析,为临床采取积极的防控措施奠定基础.方法 收集2007年1月至2014年12月临床非重复分离的阴沟肠杆菌,筛选碳青霉烯类抗菌药物敏感性降低的菌株,通过改良Hodge试验（MHT）及乙二胺四乙酸（EDTA）协同试验检测碳青霉烯酶表型,PCR 扩增碳青霉烯酶基因型blaKPC、blaIMP、blaVIM、blaOXA-48及blaNDM-1 ,阳性结果进行DNA测序并Blast比对确定分型.对耐碳青霉烯类阴沟肠杆菌进行接合试验,通过药敏试验和基因扩增验证接合情况.同时收集耐药菌株感染患者的临床资料,分析其临床感染流行病学数据.结果 经MHT、EDTA协同试验及PCR扩增测序共检测出产碳青霉烯酶阴沟肠杆菌64株,其中70.3%（45/64）来自院内感染,29.7%（19/64）来自社区感染;64株菌主要分离于分泌物占65.6%（42/64）,痰标本占23.4%（15/64）,临床分布以骨外科、烧伤科、重症监护室及儿科为主,分别占43.8%、21.9%、18.8%及14.1%;床位变更、侵袭性操作及留置导管是产酶菌株产生的高危因素,产酶株感染患者在细菌分离前住院天数较多,治愈率更低,住院总天数更多,使用头孢类加酶抑制剂复合制剂及碳青霉烯类频次更高（均P〈0.05）;除多粘菌素及替加环素外,64株菌对常见抗菌药物呈现多重耐药趋势;Blast 比对显示,29 株为blaIMP-4型,35株为blaIMP-8型,未检出blaVIM、blaOXA-48、blaNDM-1基因型;接合试验证实接合子与供体菌具有相似的耐药性,可扩增出相同的耐药基因.结论 阴沟肠杆菌耐药情况日趋严重,IMP-4型和IMP-8 型碳青霉烯酶是菌株产酶的主要型别,耐药基因可通过质粒进行水平传播且已在医院科室中局部流行,必须及时控制耐药菌株产生的高危因素.Objective To study the genotypes and clinical characteristics of carbapenemase -producing Enterobacter cloacae （E.cloacae） , and lay the foundation for active control of nosocomial infection.Methods E.cloacae isolates were collected from January 2007 to December 2014.Strains which showed decreased sensitivity to carbapenem were screened out by the modified Hodge test （MHT） and EDTA-disk synergy test.The genotype of blaKPC , blaIMP , blaVIM , blaOXA-48 and blaNDM-1 were detected by PCR amplication, the product of PCR was sequenced and conducted by Blast （http：//blast.ncbi.nlm.nih.gov/Blast.cgi）.Conjugal transfer experiment was conducted to prove horizontal transmit of carbapenemase gene produced by E.cloacae.Meanwhile , the clinical epidemiological data of patients infected by selected strains were also analyzed.Results Sixty-four carbapenemase producing E.cloacae were detected by MHT, EDTA-disk synergy test and PCR amplification.Forty-five strains （70.3%） out of 64 strains infection came from nosocomial infection , while 19 strains （29.7%） from the community infection.The strains were mainly isolated from secretions samples and sputum samples , which accounted for 65.6% （42/64） and 23.4%（15/64） separately.The mainly clinical departments were orthopaedics （43.8%）, department of burn （21.9%）, ICU （18.8%） and pediatrics （14.1%）.Bed changing, invasive operation and indwelling catheter were risk factors for the transmission of carbapenemase producing E.cloacae, and infected patients had longer time of staying in hospital , lower cure rate and higher frequency of cephalosporins enzyme inhibitor compound or carbapenem agents administration （all P〈0.05）.Sixty-four strains showed increased MIC to most of the antibiotics except for polymyxin and tigecycline.Among the 64 strains, 29 strains were genotype blaIMP-4 and 35 strains were genotype blaIMP-8 by Blast alignment , no genotype blaVIM , blaOXA-48 and blaNDM-1 were detected.Result of conjugal transfer experiment showed

关 键 词：阴沟肠杆菌 碳青霉烯酶 基因型 临床感染 

分 类 号：R446.5[医药卫生—诊断学]