儿童患者中分离350株流感嗜血杆菌的分布和耐药性分析

Distribution and antibiotic resistance profile of 350 strains of Haemophilus influenzae isolated from children

目的研究儿童流感嗜血杆菌临床分布及耐药性,指导临床合理用药。方法对2014-2015年北京儿童医院住院患儿临床送检标本分离出350株流感嗜血杆菌的分布、产β内酰胺酶情况和药敏结果进行回顾性分析。药敏试验采用纸片扩散法,头孢硝噻吩纸片法测定β内酰胺酶,按照临床和实验室标准化协会(CLSI)2014年的标准进行药敏检测和结果判断。使用WHONET 5.6和SPSS15.0软件进行数据统计分析。结果流感嗜血杆菌感染多见于婴幼儿,常见合并其他病原感染。β内酰胺酶阳性率为53.1%,对甲氧苄啶-磺胺甲唑的耐药率最高,为76.9%,对环丙沙星、头孢唑肟、氯霉素、四环素、阿莫西林-克拉维酸、头孢呋辛、阿奇霉素、头孢克洛、氨苄西林敏感率分别为99.1%、98.9%、95.4%、88.3%、87.7%、74.9%、65.4%、56.6%、46.0%,未检出对头孢曲松、美罗培南不敏感的流感嗜血杆菌。结论儿童分离的流感嗜血杆菌产β内酰胺酶阳性率很高,是流感嗜血杆菌对氨苄西林耐药的主要机制,其高产酶特点使氨苄西林不能作为临床一线用药。流感嗜血杆菌对甲氧苄啶-磺胺甲唑的耐药率最高,对β内酰胺类以外抗菌药物,最敏感的是环丙沙星,其次为氯霉素。

Objective To analyze the distribution and antibiotic resistance profile of Haemophilus influenzae strains isolated from children for better antibiotic use. Methods The clinical and laboratory data concerning 350 strains of H. influenzae were collected and analyzed retrospectively from 2014 to 2015 in our hospital, including pathogen source, production of beta lactamases and antimicrobial susceptibility. Antimicrobial susceptibility testing was carried out by using disk diffusion method. The results were interpreted according to the breakpoints of the Clinical and Laboratory Standards Association(CLSI) in 2014, and analyzed using WHONET 5.6 software. Results H. influenzae infection was more common in infants and young children. The prevalence of beta lactamase was 53.1% in H. influenzae isolates. The H. influenzae isolates showed the highest resistance rate to trimethoprimsulfamethoxazole(76.9%), but relatively high susceptible rate to ciprofloxacin(99.1%), ceftizoxime(98.9%), chloramphenicol(95.4%), tetracycline(88.3%), amoxicillin-clavulanic acid(87.7%), cefuroxime(74.9%), azithromycin(65.4%), cefaclor(56.6%) and ampicillin(46.0%). All these H. influenzae strains were susceptible to ceftriaxone and meropenem. Conclusions Beta-lactamases are highly prevalent in the H. influenzae strains isolated from children, which is the main mechanism underlying ampicillin resistance in H. influenzae. Ampicillin is therefore not appropriate for first-line treatment of H. influenzae infections. The H. influenzae strains are highly resistant to trimethoprim-sulfamethoxazole. In addition to beta-lactams, ciprofloxacin is the most active agent against H. influenzae strains, followed by chloramphenicol.