幽门螺杆菌对克拉霉素、阿莫西林、甲硝唑体外耐药性和敏感性的初步分析

Prevalence of Helicobacter pylori resistant to clarithromycin, am oxicillin and metronidazole in children

目的 了解儿童幽门螺杆菌 (Helicobacerpylori,简称Hp)对克拉霉素、阿莫西林、甲硝唑体外敏感性和耐药性。方法 4 4例Hp菌株取自 2 0 0 2年 10月～ 2 0 0 3年 11月在浙江大学医学院附属儿童医院进行胃镜检查患儿胃黏膜标本 ,分离培养获得 ,采用琼脂稀释法进行体外抗生素敏感试验 ,检测Hp菌株对 3种抗生素最低抑菌浓度 (MIC) ,并计算MIC50 和MIC90 值和Hp菌株对 3种药物的耐药率。结果 克拉霉素耐药率为 18 2 % (8/44 ) ,阿莫西耐药率为 9 1% (4 /44 ) ,甲硝唑耐药率为 31 8% (14 /44 ) ;其MIC值范围分别为 <0 12 5～ 6 4 μg/ml,<0 12 5～ 6 4 μg/ml和 <0 12 5～ 12 8μg/ml。克拉霉素半数抑菌浓度 (MIC50 )和 90 %抑菌浓度 (MIC90 )分别为MIC50 <0 12 5 μg/ml,MIC90 为 8μg/ml;,阿莫西林MIC50 <0 12 5 μg/ml,MIC90 为 0 5 μg/ml;甲硝唑MIC50 为 0 5 μg/ml,MIC90 为 12 8μg/ml。Hp菌株对克拉霉素耐药率高于国内成人水平 ,对甲硝唑耐药率则低于成人水平 ,但耐药菌株MIC值和MIC90 均在较高水平。 3株Hp菌株对阿莫西林、克拉霉素和甲硝唑同时耐药 ,多重耐药率为 6 8% (3/44 )。结论 儿童Hp对甲硝唑耐药率较高 ,对克拉霉素耐药率较成人高 ,已有耐阿莫西林菌株 ,部分菌株多重耐药。

Objective To investigate the prevalence of Helicobacter pylori (Hp) resistant to clarithromycin, amoxicil lin and metronidazole in children. Methods A total of 4 4 Hp clinical isolates were cultured from children patients with Hp gastritis a nd peptic ulcer who underwent gastroscopy during the period from October 2002 to November 2003 in Children′s Hospital affiliated to Medical College of Zhejiang University. Nineteen of the patients were girls and 25 boys. The mean age wa s 8.66±2.66 years (3～14 years). The susceptibilities of the 44 Hp strains t o clarithromycin, amoxicillin and metronidazole were tested by agar dilution test to determine minimum inhibitory concentration (MIC) 50, MIC 90 and re sistance rates were also calculated. Results Among the 44 Hp strains isolated from children, 8, 4, and 14 strains were resistant to cla rithromycin, amoxicillin and metronidazole and the resistant rate was 18.2% (8/ 44), 9.1% (4/44) and 31.8% (14/44), with MICs for all strains ranging from <0 .125 μg/ml to 64 μg/ml, <0.125 μg/ml to 64 μg/ml and <0.125 μg/ml to 128 μg/ml, respectively. MIC 50 and MIC 90 of clarithromycin, amox icillin and metronidazole were <0.125 μg/ml, 8 μg/ml; <0.125 μg/ml,0.5 μ g/ml;0.5 μg/ml,128 μg/ml, respectively. The prevalence of Hp resistant to clarithromycin was higher in children than that in adults, while to metronidazol e was lower than that in adults with high MICs (32～128 μg/ml) and MIC 90 (128 μg/ml) of metronidazole for resistant isolates. Three multidrug resistan t strains (6.8%) were simultaneously resistant to these three antibiotics. Conclusions The prevalence of Helicobacter pylori resis tant to metronidazole was high in children, and the rate of resistance to clarit hromycin was higher than that isolated from adults. Amoxicillin-resistant stra ins were now found, and multidrug resistant strains which resistant to the three antibiotics also emerged.