白血病患者感染产新德里金属β-内酰胺酶大肠埃希菌的临床特征

Clinical characteristics and treatment of leukemia cases infected with NDM-1-producing Escherichia coli

目的分析白血病患者感染产新德里金属β-内酰胺酶(NDM-1)大肠埃希菌的临床特征及抗感染治疗方案,为临床血液病患者预防"超级细菌"感染及治疗提供帮助。方法采集2014年3例白血病耐碳青酶烯类大肠埃希菌感染患者送检的血液标本,以改良Hodge试验对耐碳青霉烯类肠杆菌进行碳青霉烯酶筛选,PCR特异性扩增及测序进行确认;脉冲场凝胶电泳和多位点序列分析(MLST)技术分析耐药菌株间的亲缘性;并收集感染患者的临床资料,对其临床特征及抗菌药物治疗进行分析。结果 2014年10月检出3例白血病感染产NDM-1大肠埃希菌患者,菌株经测序确认携带NDM-1基因,对常见的临床抗感染药物(包括碳青霉烯类)均耐药,仅对氨基糖苷类药物(阿米卡星)敏感;脉冲场凝胶电泳显示,患者1和患者2所感染细菌同源性100.0%,与患者3同源性也较高;MLST分析3株菌均为ST167型,为同一克隆菌株流行;依据药敏试验抗感染治疗后,1例有效,但出现肾功能异常,1例放弃治疗,1例死亡。结论携带此基因的菌株可能在3例患者间进行了水平传播,使用敏感药物阿米卡星治疗有效,但易出现肾功能损害。

OBJECTIVE To analyze the clinical characteristics and anti-infective treatment of leukemia cases infected with New Delhi metallo-beta-lactamase 1（NDM-1）producing Escherichia coli,which could help to prevent and treat super bacterial infections for leukemia patients.METHODS Modified Hodge test was used for carbapenemases screening of carbapenemases-resistant enteric bacilli in blood samples from three leukemia patients infected with carbapenemases-resistant E.coli in the year 2014.The NDM-1gene was confirmed by the specificity of the PCR amplification and sequencing.Pulse field gel electrophoresis and multilocus sequence technique（MLST）were used to analyze affinity of resistant strains.Clinical data were collected to analyze the clinical characteristics and antibiotic treatment of the three patients.RESULTSIn Oct.2014,three cases of E.coli isolates producing NDM-1were detected.All of them were resistant to common clinical medication（including carbapenemases drugs）,and only sensitive to aminoglycosides（Amikacin）.Pulsed field gel electrophoresis showed that the homology of strains of patient 1and 2was 100.0%.They were also closed to patient 3.MLST showed that 3strains were ST167 and were the same cloning epidemic strains.After anti-infective treatment according to the results of drug sensitivity,one case was effectively treated,but had abnormal renal function,one gave up the treatment and another one died.CONCLUSIONThe strains carrying the NDM-1gene may be spread horizontally among the 3patients.Amikacin was effective but easy to cause abnormal renal function.