中国14家教学医院2005-2008年临床分离肺炎链球菌耐药性分析

Antimicrobial resistance surveillance study among Streptococcus pneumoniae clinically isolated from 14 teaching hospitals in 2005-2008 in China

目的 监测2005-2008年我国不同地区14家教学医院临床分离肺炎链球菌的耐药性,为临床经验用药提供科学建议.方法 2005-2008年从14家教学医院收集非重复的1 317株临床分离肺炎链球菌,其中2005年271株、2006年391株、2007年363株、2008年292株.菌株主要为社区呼吸道感染病原菌,即以呼吸道感染收治的门诊和急诊患者或入院48 h内发生呼吸道感染的患者中分离的肺炎链球菌.菌株分离地区包括华北地区、东北地区、华南地区、华中及西北地区以及华东地区.患者按年龄分为成人组（≥18岁）、青少年组（6～17岁）和儿童组（≤5岁）.菌株经中心实验室复核后,采用Etest法、琼脂稀释法或纸片扩散法测定8类17种抗菌药物的MIC或抑菌圈直径,数据输入WHONET5.5软件分析敏感率、中介率、耐药率、MIC50、MIC90.结果 肺炎链球菌对利奈唑胺（100%）和氟喹诺酮类药物（95.2%～99.7%）保持了高的敏感率.对于β内酰胺类药物,菌株对阿莫西林-克拉维酸敏感率为73.8%～92.1%,对青霉素、头孢曲松和头孢吡肟也有较高的敏感率,但逐年降低.3种二代头孢菌素的敏感率较低（2008年为36.3%～38.4%）.对于红霉素、阿奇霉素、克林霉素、甲氧苄啶-磺胺甲 唑和四环素,菌株的敏感率均较低且逐年下降.PISP的比例在逐年增大,从2005年的4.4%上升至2008年的20.2%.华北地区的PNSP发生率较低（6.0%）,而华中及西北地区和华东地区的PNSP发生率较高（30.1%和38.7%）.成人组的PNSP发生率（15.7%）明显低于儿童组（33.0%）,也低于青少年组（38.2%）.结论 肺炎链球菌对利奈唑胺和氟喹诺酮类药物在2005-2008年间保持了较高的敏感性,而对青霉素类和头孢菌素类的敏感性逐年降低,临床需慎用对肺炎链球菌活性较低的药物,包括大环内酯类、克林霉素、甲氧苄啶-磺胺甲 唑和四环素.

Objective To investigate antimicrobial resistance among Streptococcus pneumoniae clinically isolated from 14 teaching hospitals located at different areas in China in 2005-2008 and to give logical guidance for clinical empirical therapy.Methods A total of 1 317 non-repetitive S.pneumoniae isolates in 14 teaching hospitals from 2005-2008 were collected and sent to the central lab for reidentification and susceptibility testing, including 271 isolates collected in 2005, 391 isolates collected in 2006, 363 isolates collected in 2007 and 292 isolates collected in 2008. Most of the isolates were from community-acquired respiratory tract infections, which were isolated from outpatient or emergency department patients with respiratory tract infections or those patients with respiratory tract infections within ≤48 hours hospitalization.The districts where the organisms were isolated include North China, Northeast China, South China, Central and Northwest China and East China.The patients included adults, teenagers and children.The minimum inhibitory concentrations （MICs） or inhibitory zone diameter of 17 antimicrobial agents were determined by Etest method, agar dilution method or disk diffusion method.WHONET5.5 software was used to analyze susceptibility rate, intermediate rate, resistance rate, MIC50 and MIC90.Results Linezolid （100%） and fluoroquinolones （95.2%-99.7%） showed excellent activities against S.pneumoniae.Among β-lactams, amoxicillin-clavulanic acid remained high activities （73.8%-92.1%）,followed by penicillin, ceftriaxone and cefepime with year-over-year decrease in activities.The activities of three second-generation cephalosporins were low （36.3%-38.4% in 2008）.The activities of erythromycin, azithromycin, clindamycin, trimethoprim/sulfamethoxazole and tetracycline against S.pneumoniae were poor and decreased year over year.The incidence of penicillin non-susceptible S.pneumoniae （PNSP） was increasing especially for PISP （from 4.4% in 2005 to 20.2% in 2008）.The incidence of PNSP in North China was low （6.0%）, while this value were high in central China and East China （30.1% and 38.7%, separately）.The incidence of PNSP in adults （15.7%） was obviously lower than that in children（≤5 years：33.0%） and teenagers （6-17 years：38.2%）.Conclusions linezolid and fluoroquinolones showed excellent in vitro activity against S.pneumoniae, followed by penicillin and cephalosporins with year-over-year decrease of activity. Clinicians should pay more attention when using those antimicrobial agents with poor activity against S.pneumoniae, which include macrolides, clindamycin, trimethoprim/sulfamethoxazole and tetracycline.