2000～2002年北京、上海及广州三地儿童携带流感嗜血杆菌抗生素敏感性监测

Surveillance of antimicrobial susceptibility of Haemophilus influenzae isolates from children in Beijing, Shanghai, and Guangzhou 2000-2002

目的了解当前我国儿童携带流感嗜血杆菌对常用抗生素的敏感性情况,以便有效指导临床合理用药和预防。方法采用E-test最小抑菌浓度(MIC)方法及KB纸片扩散法对2000-2002年北京、上海、广州3所儿童医院上呼吸道感染儿童携带流感嗜血杆菌进行10种常用抗生素敏感性检测。结果 氨苄青霉素对898株流感嗜血杆菌的MIC50和MIC90分别为0.25μg/ml和4μg/ml,敏感性88.0％,10.6％菌株对氨苄青霉素耐药,所有氨苄青霉素中度敏感株和耐药株均产β-内酰胺酶,分离株产β-内酰胺酶率为12％;分离株对阿莫西林/克拉维酸、头孢曲松、头孢呋辛敏感性均为100％;头孢克罗对分离株MIC50和MIC90分别为1.5μg/ml和3μg/ml,敏感性略低(96.1％),耐药率1.8％。流感嗜血杆菌对阿奇霉素、环丙沙星敏感率分别为100％和99％,对氯霉素、四环素、磺胺甲(?)唑/甲氧苄氨嘧啶(SMZ/TMP)耐药率分别为11％、18％、54.4％。北京和上海分离株对四环素敏感性分别为57％和61％,明显低于广州分离株(81％);广州和上海分离株对SMZ/TMP敏感性分别为47％和54％,明显高于北京株(35％);2000-2002年的3年中,分离株对氨苄青霉素敏感性呈逐年下降趋势,对氨苄青霉素总体耐药率由2000年的7.7％增加至2002年的14.5％。本研究中,34.5％分离株对8种抗生素均敏感,多重耐?

Objective To investigate the situation of antibiotic resistance of Haemophilus influenzae isolates from Chinese children. Methods Eight hundred and ninety-eight strains of H. influenzae isolated from randomly selected pediatric out-patients in Beijing, Shanghai and Guangzhou 2000 -2002 underwent determination of antibiotic susceptibility by E test MIC method for β-lactam antibiotics ( ampicillin, amoxicillin/clavulanic acid, ceftriaxone, cefuroxime, and cefaclor) and KB disc diffusion method for chloramphenicol, tetracycline, sulfamethoxazole/trimethoprim ( SMZ/TMP ) , azithromycin, and ciprofloxacin. Results The average rate of β-lactamase production among these isolates was 12%. The MIC50 and MIC90 of ampicillin were 0.25 μg/ml and 4 μg/ml respectively for the 898 isolates, 88% of the isolates were susceptible to ampicillin and 10. 6% was resistant. There was no β-lactamase negative strains among the ampicillin intermediately-susceptible and resistant strains. All the isolates were susceptible to amoxicillin/clavulanic acid,ceftriaxone,cefuroxime and azithromycin. 96.1% of the H. influenzae isolates generally remained susceptible to cefaclor with a MIC50 of 1. 5 μg/ml arid a MIC90 of 3 μg/ml, and 99% of the isolates were susceptible to ciprofloxacin. The susceptibility rate to tetracycline of the isolates from Beijing and Shanghai areas were 57% and 61% respectively, both lower than the susceptibility rates of the isolates from Guangzhou (81% ), while the resistant rate to SMZ/TMP of the isolates from Beijing was 35% , lower than those of the isolates from Guangzhou (47% ) and Shanghai (54% ). The resistant rate to ampicillin was 7. 7% in 2000 and was increased to 14. 5% in 2002. 34. 5% of all the isolates were susceptible to 8 antimicrobial agents while 12. 8% was multi-drug resistant. 58. 5% of the isolates were distributed in five major antimicrobial resistance profiles in which SMZ/TMP resistance (29. 8% ) was the most prevalent, followed by SMZ/TMP and tetracycline combined resistance ( 12. 5% ) and tetracycline resistance (9.4). The ampicillin non-susceptible isolates had higher resistant rates to cefaclor (23. 5% ) , tetracycline (63. 3%) , SMZ/TMP (74. 5%) and chloramphenicol (63. 3%) than the ampicillin susceptible strains (1. 6%, 51. 4%, 11. 1% and 4. 9% respectively). Conclusion β-lactamase production and ampicillin resistance among the isolates from Chinese children are increasing generally during the period 2000 - 2002. There is variation of resistance among different regions. There are strong correlations between ampicillin resistance and resistance to cefaclor, chloramphenicol, and tetracycline among the H. Influenzae isolates.