RÉSUMÉ
Objectives To investigate the homology and drug resistance gene of Group B Streptococcus ( GBS) Resistance induced by Clindamycin and provide basic data for clinical prevention and treatment of GBS Resistance infection induced by Clindamycin .Methods 921 strains of GBS were isolated at Obstetrics&Gynecology Hospital of Fudan University from January , 2014 to December , 2015.VITEK2-compact automatic bacterial susceptibility instrument was used to test their sensitivity to 7 antibacterial drugs.63 positive strains were chosen through D-inhibition zone trial which were drug resistant to Erythromycin and susceptible or intermediary to Clindamycin .The strain′s sequence type was identified by the method of multilocus sequence typing ( MLST typing ) .The drug resistance genes mefA & ermB to Erythromycin were detected by using PCR method .The analysis was carried out to reveal the relevance to drug resistance , multilocus sequence typing and drug resistance gene .Results Among 921 strains of GBS , the drug resistance rate was respectively 53.4％ ( 492/921 strains ) to Erythromycin , 50.2％ ( 462/921 strains) to Clindamycin, 34.7％ ( 320/921 strains ) to Levofloxacin and 7.5％ ( 69/921 strains ) to Nitrofurantoin.The drug resistance rate of Levofloxacin for 63 GBS strains was 27.0％(17/63 strains) and no drug resistant strain was found to Penicillin , Vancomycin & Nitrofurantoin.12 different ST types were involved in total, including a new ST type:ST1072.The most common ones were ST12 (30.1％) (20/63 strains) &ST19 (25.4％) (16/63 strains).The drug resistance rate of Levofloxacin with ST 19 (75.0％) (12/16 strains) was much higher than that of other ST types .The relevance ratio of mefA and ermB among 63 GBS strains was respectively 27.0％(17/63 strains) and 41.3％(26/63 strains).Conclusions The genetic diversity existed in Group B Streptococcus resistance induced by Clindamycin detected in this study . There was significant difference on drug resistance and relevant drug resistant genes among different ST types.