Abstract:

Objective    To investigate the antibiotic resistance patterns and epidemiological features of Haemophilus influenzae（HI） strains，and to provide reference for choosing antibiotics in clinical treatment. Methods    A total of 546 strains were identified from 2007 to 2014  in Children’s Hospital，Zhejiang University School of Medicine and 98.7% were isolated from respiratory tract specimens. Three hundred and forty-eight isolates（63.7%） were from boys and the male-female ratio was 1.76∶1. The age of the infected children ranged from 7 days to 13 years. Haemophilus influenza strains were cultured in Haemophilus selective medium. All strains were identified with Ⅴ factor and Ⅹ factor requirement test and the drug-sensitivities tests were performed with disk diffusion method. Cefinase was used to detect β-lactamase. Results    Most of the strains（331 isolates，60.6%） were isolated in spring，while only 23（4.2%） were isolated in autumn. The β-lactamase positive strains increased annually and the total rate was 26.7%（146）， and 28.0%（153  strains） were resistant to ampicillin. The multi-resistance strains were 60（11.0%） and the major multi-resistance type was those resistant to ampicillin，trimethoprim-sulfamethoxazole and clarithromycin at the same time，and the multi-resistance rate in β-lactamase-positive strains were significantly higher than that in β- lactamase- negative strains（χ2＝145.1，P＜0.005）. Conclusion    Most of the Haemophilus influenzae strains are isolated from respiratory samples in children younger than 1 year old in our hospital，and the peak months were February，March，April and May. The resistance rate to ampicillin of HI strains has increased annually，whereas to the second generation of cephalosporin，HI strains are still sensitive and they can be used in clinical treatment as the first choice.

Key words: Haemophilus influenzae, child, antibiotic resistance

摘要：

目的    了解流感嗜血杆菌（haemophilus influenza，HI）患儿分离株的耐药模式及流行特点，为临床经验治疗提供依据。方法　2007年1月至2014年12月浙江大学医学院附属儿童医院共检出HI菌株546株，98.7%的菌株来自呼吸道标本。男性患儿检出348株，女性198株，男女比例1.76∶1。年龄范围为7 d至13岁。HI培养采用嗜血杆菌专用培养基，菌株的鉴定采用Ⅴ因子和Ⅹ因子需求试验，药敏试验采用纸片扩散法，β内酰胺酶检测采用Cefinase 纸片法。结果　季节分布以春季为主，共331株（60.6%），秋季最少，仅23株（4.2%）。146株（26.7％）菌株 β内酰胺酶阳性，菌株 β内酰胺酶阳性率逐年上升。153株（28.0%）菌株对氨苄西林耐药。多重耐药株占60株（11.0％），最常见者为同时耐氨苄西林、复方磺胺甲恶唑和克拉霉素，β内酰胺酶阳性菌株多重耐药率显著高于阴性菌株（χ2＝145.1， P＜0.005）。结论　浙江大学医学院附属儿童医院HI株主要来自呼吸道标本， 感染患儿以1岁以内为主，每年2—5月为感染高峰季节，菌株对氨苄西林的耐药性有逐年上升趋势，对二代头孢菌素仍保持较高敏感性，其可作为经验治疗首先药物。

关键词: 流感嗜血杆菌, 儿童, 耐药性