Outbreak of NDM-1-producing Klebsiella pneumoniae ST76 and ST37 isolates in neonates
Outbreak of NDM-1-producing Klebsiella pneumoniae ST76 and ST37 isolates in neonates
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DOI：
10.1007/s10096-016-2578-z
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发表时间：
2016-04-01
影响因子：
4.5
通讯作者：
Hu, F.
中科院分区：
文献类型：
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作者：
Zhu, J.;Sun, L.;Hu, F.
本研究的目的是调查中国上海儿童医院碳青霉烯类耐药肺炎克雷伯菌（CRKP）的流行病学特征。2014年3月至6月期间，从儿科患者中采集了22株非重复CRKP菌株。采用琼脂稀释法进行药敏试验。通过聚合酶链反应（PCR）和DNA测序对β-内酰胺酶进行表征。通过偶联实验研究了bla（NDM-1）的转移性。用S1核酸酶脉冲场凝胶电泳（S1-PFGE）和Southern杂交对携带抗生素抗性基因的质粒进行了鉴定。PFGE和多位点序列分型（MLST）的克隆相关性进行了评估。对患者的临床资料进行回顾性分析。除替加环素和粘菌素外，22株CRKP菌株对大多数检测的抗菌药物均耐药。总体而言，这些菌株中分别有59%、77%和100%对亚胺培南、美罗培南和厄他培南耐药。在77.3%（17/22）的CRKP菌株中bla（NDM-1）为阳性，其中16株来自住院患者的菌株被指定为ST 37（n = 9）和ST 76（n =7），1株来自门诊患者的菌株属于ST 846。17株bla（NDM-1）阳性菌株属于PFGE A型9株，C型7株，B型1株。88.2%（15/17）的菌株能将携带bla（NDM-1）的质粒通过接合转移到受体大肠杆菌J53中。杂交结果表明，携带bla（NDM-1）基因的质粒大小约为50-240 kb。这是第一次报道由产NDM-1的K.肺炎链球菌ST 76和ST 37。
The purpose of this study was to investigate the epidemiological characteristics of carbapenem-resistant Klebsiella pneumoniae (CRKP) in Shanghai Children's Hospital in China. Twenty-two non-duplicate CRKP strains were collected from pediatric patients between March and June in 2014. Antimicrobial susceptibility testing was conducted by the agar dilution method. Beta-lactamases were characterized by polymerase chain reaction (PCR) and DNA sequencing. The transferability of bla (NDM-1) was investigated by conjugation experiment. The plasmids bearing antibiotic resistance genes were characterized by S1 nuclease pulsed-field gel electrophoresis (S1-PFGE) and Southern hybridization. Clonal relatedness was evaluated by PFGE and multilocus sequence typing (MLST). The clinical data of patients were retrospectively reviewed. The 22 CRKP strains were resistant to most of the antimicrobial agents tested, except tigecycline and colistin. Overall, 59, 77, and 100 % of these strains were resistant to imipenem, meropenem, and ertapenem, respectively. The bla (NDM-1) was positive in 77.3 % (17/22) of the CRKP strains, of which the 16 isolates from inpatients were designated as ST37 (n = 9) and ST76 (n =7) and one isolate from an outpatient belonged to ST846. The 17 bla (NDM-1)-positive isolates belonged to PFGE type A (n = 9), type C (n = 7), or type B (n = 1). The plasmids bearing bla (NDM-1) could be transferred into recipient Escherichia coli J53 through conjugation in 88.2 % (15/17) of the strains. The hybridization results showed that the plasmids carrying the bla (NDM-1) gene were approximately 50-240 kb in size. This is the first report of an outbreak caused by NDM-1-producing K. pneumoniae ST76 and ST37 among neonates.