Abstract:

Objective To investigate the serotypes and drug resistance causing invasive Streptococcus agalactiae（Group B Streptococcus，GBS）infection in children，and to provide a reference for clinical reduction of GBS infection and rational drug treatment. Methods GBS was isolated from sterile site specimens in Beijing Friendship Hospital of Capital Medical University from January 2012 to December 2018，and serotyping and in vitro drug susceptibility test were performed. Results Totally，139 cases were neonates（61.2%），followed by infants（38.8%）. A total of 185 isolates of invasive GBS were isolated，of which 46.0%（64/139）were isolated from blood specimens，20.9%（29/139）were isolated from cerebrospinal fluid specimens，and 33.1%（46/139）were isolated from both blood and cerebrospinal fluid specimens. A total of 5 serotypes were isolated，of which type Ⅲ had the highest determination rate（54.6%，76/139），followed by type Ⅰb（28.1%，39/139），type Ⅰa（12.9%，18/139），type Ⅱ and type Ⅴ（2.2%，3/139，respectively）. The drug resistance rate of 139 isolates of GBS to erythromycin was the highest（89.9%），followed by clindamycin（74.1%）and levofloxacin（31.7%）. No isolates insensitive to penicillin，ceftriaxone，cefepime，linezolid and vancomycin were determined. There were some differences in drug resistance among different serotypes of GBS. Conclusions Invasive GBS infection in children can cause bloodstream infection and meningitis，and serotyping and drug susceptibility test are important for the prevention and treatment of pediatric clinical infections.

Key words: Streptococcus agalactiae, Children, Invasive infection, Serotype, Drug resistance