149例革兰阴性杆菌血流感染患儿病原菌耐药分析

目的：了解我院住院患儿革兰阴性杆菌血流感染的病源菌构成及其耐药性，为临床治疗用药提供参考。方法：采用VITEK-2全自动微生物分析鉴定系统和NCCLS（2010年）的判断标准，对2011年儿科149例患儿血标本分离的革兰阴性杆菌进行鉴定和药敏试验。结果：149例患儿的血标本中分离出肺炎克雷伯菌69株，其中产超广谱8内酰胺酶（ESBLs）59株（85．51％），非产ESBLs 10株（14．49％）；大肠埃希菌30株，其中产ES—BLs 12株（40．00％），非产ESBLs菌株18株（60．00％）；鲍曼不动杆菌感染26株，其他菌24株。所有产ESBLs肺炎克雷伯菌对亚胺培南、美洛培南、左旋氧氟沙星、环丙沙星耐药率均为0；对β内酰胺类药物的耐药率明显高于非产ESBLs菌株；对哌拉西林、氨苄西林耐药率高达100．00％。他唑巴坦对产ESBLs肺炎克雷伯菌有明显的抑制作用，哌拉西林／他唑巴坦（耐药率为18．64％）对其抑菌作用强于氨苄西林／舒巴坦（耐药率为89．83％）。碳青霉烯类（亚胺培南、美洛培南）是治疗产ESBLs肺炎克雷伯菌感染的满意选择。大肠埃希菌的耐药率低于肺炎克雷伯菌。结论：儿科革兰阴性杆菌血流感染中肺炎克雷伯菌是主要致病菌，产ESBLs肺炎克雷伯菌检出率较高。亚胺培南和美洛培南是治疗儿科产ESBLs肺炎克雷伯菌、大肠埃希菌血流感染的较好选择。

Analysis of resistance to antibiotics of Gram-negative bacilli isolated from 149 children with blood stream infections

Objective： To investigate the pathogens and drug resistance of Gram-negative bacilli in children with blood stream infections, and to provide a reference for clinical medication. Methods： According to National Committee for Clinical Laboratary Standards （2010）, Gram-negative bacilli isolates from blood specimens of 149 children admitted in 2011 were identified, and their antimierobial susceptibility was tested by VITEK-2 automatic identification microbiological analysis system. Results： Sixty-nine strains of Klebsiella pneumoniae were isolated from blood samples of 149 children, in which 59 （85.51%） were extended-speetrmn β-lactamases producing strains （ESBLs）, 10 （14.49 %） were non-ESBLs-producing strains. In 30 strains of intestine Escherichia coli bacteria, 12 （40.00 %） were ESBLs-producing strains and 18 （60.00 %） were non-ESBLs-producing strains. Twentysix Acinetobacter baumannii strains and 24 other bacteria strains were identified. All the ESBLs-producing Klebsiella pneumoniae strains were susceptible to imipenem, cefoxitin, Levofloxacin, and Ciprofloxacin, and their drug resistance to β-1aetam was significantly higher than non-ESBLs-producing strains, and the resistance rates to piperacillin and ampicillin was as high as 100.00 %. Tazobactam inhibited ESBLs-producing Klebsiella pneumoniae significantly. The inhibitory effect of piperacillin/tazobactam on ESBLs-producing Klebsiella pneumoniae was stronger than ampicillin / sulbactam（resistance rates was 18. 64% and 89.83% respectively）. Carbapenems（imipenem, meropenem） were good choice for ESBLs producing Klebsiella pneumoniae infection. The resistance rate of Escherichia coli was lower than that of Klebsiella pneumoniae. Conclusions： Klebsiella pneumoniae is a major pathogen of pediatric blood stream infections due to Gram-negative bacilli, in which the incidence of ESBLs-producing Klebsiella pneumoniae infection is very high. Imipenem and meropenem are good choice for treatment of infections caused by ESBLs-producing Klebsiella pneumoniae and Escherichia coli bacteria.