摘要目的 分析北京市儿童A组链球菌临床分离株对抗菌药物的耐药特点,为临床用药提供依据.方法 2011年5-7月从北京市36家医院收集儿童A组链球菌临床分离株.采用VITEK 2全自动生化分析仪测定上述菌株对10种抗菌药物的最低抑菌浓度(MIC),计算敏感率(S％)、中介率(I％)、耐药率(R％)；用双纸片法(D实验)检测菌株对大环内酯类抗菌药物的耐药表型.结果 共采集咽拭子3315份,分离A组链球菌633株,咽拭子培养阳性率为19.1％.菌株对青霉素、氨苄西林、链阳霉素、利奈唑胺、替加环素和万古霉素的敏感率达100％,其次为左氧氟沙星(96.5％,611/633).对红霉素、四环素和克林霉素有较高的耐药率,依次为96.1％ (608/633)、93.7％(593/633)和79.3％ (502/633).共观察到9种耐药模式,以红霉素、克林霉素和四环素联合耐药为主(72.7％,460/633),其次为红霉素和四环素联合耐药(18.0％,114/633).608株对大环内酯类耐药的菌株中,83.2％(506/608)表现为固有型耐药(cLMS),诱导型耐药(iLMS)占16.0％(97/608),5株表现为主动外排型耐药.学龄儿童和菌株为郊区来源是A组链球菌对四环素耐药率的相关因素,OR值及其95％CI分别为2.43(1.16～ 5.09)和2.35(1.47～3.73)；菌株为郊区来源是A组链球菌对克林霉素的耐药率的相关因素,OR值及其95％CI为0.48(0.25 ～0.92).结论 北京市儿童分离的A组链球菌对青霉素、氨苄西林全部敏感,对红霉素、四环素和克林霉素耐药水平较高,耐药表型以固有型耐药为主.研究对象职业和菌株为郊区来源是四环素耐药率相关因素,后者也是克林霉素耐药率相关因素.

abstractsObjective To analyze the characteristics of antibiotic resistance on group A streptococcus isolated from pediatrics in Beijing in 2011,to provide reference for clinical drug administration.Methods Strains of group A streptococcus were collected from the Departments of Pediatrics in 36 hospitals at different Districts of Beijing,from May to July 2011.Minimal inhibitory concentrations (MIC) with ten antibiotics of these isolates were tested by VITEK 2 Compact method.All the Susceptibility rate (S％),Intermediate rate (I％) and Resistance rate (R％) were calculated according to their MIC values.The macrolides resistant phenotype of group A streptococcus was detected by D-test.Results A total of 633 (19.1％) group A streptococcus strains were cultured from 3315 throat swabs.All the isolates were susceptible to penicillin,ampicillin,streptogramin,linezolid,tigecycline,vancomycin,while 96.5％ (611/633) of the isolates were susceptible to levofloxacin.A total of the 96.1％ (608/633) isolates exhibited resistance to erythromycin.The resistance rates to clindamycin and tetracycline were 79.3％ (502/633)and 93.7％ (593/633),respectively.A total of 9 different resistant patterns were observed,with the dominant patterns as:concomitant resistance to erythromycin,clindamycin and tetracycline (72.7％,460/633),followed by combined resistance to erythromycin and tetracycline (18.0％,114/633).The most commonly seen macrolide resistant phenotype was cMLS type (83.2％).In total,97 strains belonged to iMLS type and 5 strains to M type.Data through multivariate logistic regression analysis showed that factors as occupation and samples being collected from the sub-unban areas etc.were significantly associated with the resistance rates to tetracycline and the odds ratio (95％CI) as 2.43 (1.16-5.09) and 2.35 (1.47-3.73).Isolates collected from the sub-unban areas were significantly associated with resistance rates to clindamycin,with the odds ratio (95％CI) being 0.48(0.25-0.92).Conclusion All the isolates acquired from the Pediatrics Departments in Beijing were susceptible to penicillin and ampicillin.The high resistance rates of erythromycin,clindamycin and tetracycline resistance to group A streptococcus were observed,with the major resistant phenotype as cMLS.Factors as occupation and the collection site of samples were significantly associated with the resistance rates to tetracycline while the sites of sample collection were significantly associated with the resistance rates to clindamycin.