产NDM-1型碳青霉烯酶肺炎克雷伯菌儿童血流感染的临床特征及细菌耐药性分析

Clinical characteristics and antimicrobial resistance of the bloodstream infections due to NDM-1 producing Klebsiella pneumoniae in children

目的研究产NDM-1型碳青霉烯酶肺炎克雷伯菌儿童血流感染的临床特征及细菌耐药性。方法收集首都医科大学附属北京儿童医院2011年1月-2014年8月住院患儿血培养分离的非重复耐碳青霉烯类肺炎克雷伯菌(CRKp);用微量肉汤稀释法测定15种抗菌药物的MIC值;采用PCR法确定产NDM-1菌株;回顾分析病历资料了解感染产NDM-1菌株患儿的临床特征,并与感染非产NDM-1菌株患儿进行比较。结果 52株CRKp中共检出28株产NDM-1菌株。产NDM-1菌株组均为多重耐药菌,对青霉素、头孢菌素和哌拉西林-他唑巴坦的耐药率达100%(28/28),对氨曲南、甲氧苄啶-磺胺甲唑及庆大霉素的耐药率均>75%,对亚胺培南和美罗培南的耐药率分别为100%(28/28)、92.9%(26/28)。产NDM-1菌株中碳青霉烯类高MIC值的菌株比例高于非产NDM-1菌株。产NDM-1菌株组的患儿中,82.1%(23/28)来自血液病房,常见基础疾病为血液系统恶性肿瘤(78.6%,22/28),20例(76.4%)患儿存在中性粒细胞缺乏伴发热;产与非产NDM-1肺炎克雷伯菌血流感染患儿相比,反复住院(P=0.202)、近期使用抗菌药物(P=0.615)、常见基础疾病(P=0.856)以及深静脉置管(P=0.099)方面差异无统计学意义。明确肺炎克雷伯菌感染后,37例患儿接受了碳青霉烯类药物联合敏感药物治疗。产NDM-1菌株组病死率与非产NDM-1菌株组相比无明显差异(2/28对3/24;P=0.625)。结论该院已出现产NDM-1肺炎克雷伯菌株,呈逐年增长趋势,此类细菌呈多重耐药,碳青霉烯类高MIC值的菌株所占比例高,临床特征上与非产NDM-1菌无明显区别。

Objective To investigate the clinical characteristics and antibiotic resistance of the bloodstream infections due to NDM-1 producing Klebsiella pneumoniae in children. Methods The nonduplicate carbapenem-resistant Klebsiella pneumoniae （CRKp） strains isolated from blood samples were collected in Beijing Children＇s Hospital from January 2011 to August 2014. Antimicrobial susceptibility was tested with broth microdilution method. PCR amplification and DNA sequencing were conducted targeting blaNoM-1 genes. Medical records were reviewed and analyzed. Results Of the 52 CRKp strains, bla^M_l gene was detected in 28 strains. All NDM-1-producing strains were multidrug-resistant. All the 28 isolates were resistant to penicillin, cephalosporins, piperacillin-tazobactam, and imipenem. More than 75.0% of these NDM-l-producing strains were resistant to aztreonam, trimethoprim-sulfamethoxazole, gentamicin, and meropenem （92.9%, 26/28）. NDM-l-producing isolates had higher carbapenem MICs than non-NDM-l-producing isolates. Most （82.1%, 23/28） of the NDM-l-producing isolates were isolated from hematology-oncology ward. The most common underlying disease was hematologic malignancy （78.6%, 22/28）. Febrile neutropenia was found in 20 （71.4%） patients. No difference was found between NDM-1-producing and non-NDM-1-NDM-1-producing strain and those due to non- NDM-1-producing strains.