临床患者感染无乳链球菌分离株的耐药性分析

Drug resistance of clinical isolates of Streptococcus agalactiae causing infection in patients

目的了解无乳链球菌感染的临床分布及耐药特点,为临床合理使用抗菌药物提供依据。方法无乳链球菌分离自2011年1月-2012年12月门诊及住院患者送检各类感染标本,采用纸片扩散法(K-B法)进行抗菌药物敏感性试验,红霉素和克林霉素双纸片协同试验(D试验)确定其耐药表型。结果分离的118株无乳链球菌主要分离自妇产科,占36.4%,标本主要来源于阴道分泌物,占36.4%;对红霉素和克林霉素的耐药率最高,分别为58.5%和53.4%,其中耐药表型以cMLSB型为主,对左氧氟沙星的耐药率次之,为22.0%;2011年分离的无乳链球菌对左氧氟沙星的耐药率28.6%,高于2010年的12.2%(P<0.05);其中未发现对青霉素、头孢曲松、头孢噻肟、万古霉素耐药菌株。结论青霉素仍可作为治疗无乳链球菌感染的首选药物;红霉素和克林霉素作为预防和治疗无乳链球菌感染的药物应用价值应重新评价,近年来喹诺酮类抗菌药物的耐药率较高应给予重视。

OBJECTIVE To explore the clinical distribution and drug resistance of the Streptococcus agalactiae cau-sing infection so as to provide guidance for reasonable clinical use of antibiotics.METHODS The S.agalactiae strains were isolated from the submitted specimens that were obtained from the outpatients and inpatients from Jan,2011 to Dec,2012.The drug susceptibility testing was performed by using disk diffusion method （K-B meth-od）,and the drug resistance phenotype was determined based on the erythromycin and clindamycin double disk synergy test （D-test）.RESULTS A total of 118 strains of S.agalactiae have been isolated,36.4% of the strains were isolated from the department of obstetrics and gynecology vaginal secretions were the major specimens source,accounting for 36.4%.The drug resistance rates of the S.agalactiae to erythromycin （58.5%）and clin-damycin （53.4%）were the highest.The cMLSB was the predominant drug resistance phenotype,followed by the drug resistance rate to levofloxacin （22.0%）;the drug resistance rate of the isolated S.agalactiae to levofloxacin was higher in 2011（28.6%）than in 2010（12.2%）（P〈0.05）.No strains were found to be resistant to penicillin, ceftriaxone,cefotaxime,or vancomycin.CONCLUSION Penicillin remains the preferred antibiotic for the treatment of S.agalactiae infection.It is necessary to reconsider the value of erythromycin and clindamycin in prevention and treatment of the S.agalactiae infection and focus on the increasing drug resistance rate to quinolones.