Objective To obtain information on the distribution of serotypes and antimicrobial agents susceptibilities to group B streptococcus(GBS) strains. Methods Bacterial isolates of GBS were obtained from vaginal and cervical tract of pregnant and nonpregnant women in Beijing Tian Tan Hospital. A total of 76 GBS strains were identified finally by Coagglutination. Serotyping was determinted by Standard Lancefield method. Susceptibility to test agents was assessed by determining the mininum inhibitory concentrations (MICs) with agar dilution method that was established by the National Committee for Clinical Laboratory Standards (NCCLS). Results Seven serotypes were identified among 76 GBS strains isolates. Type II(33%), III(23%) and Ia(16%) were the predominantly serotypes in pregnant and nonpregnant women. MICs of penicillin G and anpicillin were≤0.06 ?g/ml; MICs of cephazolin,cefuroxime, cefoperozone were 0.006～0.03 ?g/ml; MICs of erythromycin was 0.003～0.03 ?g/ml;MICs of gentamycin was 1～32 ?g/ml,MICs of amikacin was 4～≥64 ?g/ml,nearly 12.8% and 40.4% the strains were resistant to gentamycin and amikacin,respectively. Conclusion Our study provide useful epidemiologic data for preparation of GBS type specific vaccines which can prevent GBS infections and antimicrobial agents susceptibility patterns in China. Routine reports on GBS susceptibolities by clinical laboratories and continuous surveillance for changes in the susceptibility is of considerable clinical importance.

Objective To obtain information on the distribution of serotypes and antimicrobial agent susceptibilities to group B streptococcus (GBS) strains isolated in Beijing area from 1991 to 1996. Methods Bacterial isolates of GBS were obtained from vaginal and cervical tract of pregnant and nonpregnant women in Beijing Tian Tan Hospital by culture. A total of 76 GBS strains were identified finally by coagglutination. Serotyping was determined by Standard Lancefield method. Susceptibility to test agents was assessed by determining the minimal inhibitory concentrations (MICs) with agar dilution method that was established by the National Committee for Clinical Laboratory Standards (NCCLS).Results Seven serotypes were identified among 76 GBS strains isolates. Types Ⅱ (33%), Ⅲ (23%) and Ⅰa (16%) were the predominant serotypes in pregnant and nonpregnant women. MICs of penicillin G and ampicillin were ≤0.06 μg/ml. MICs of cephazolin, cefuroxime and cefoperozone were 0.003 μg/ml - 0.06 μg/ml. MICs of erythromycin were 0.003 μg/ml - 0.03 μg/ml. MICs of gentamycin were 1 μg/ml - 32 μg/ml. MICs of amikacin were 4 μg/ml - ≥64 μg/ml, nearly 12.8% and 40.4% of the strains were resistant to gentamycin and amikacin, respectively.Conclusions Our study provides useful epidemiologic data for preparation of GBS type-specific vaccines which can prevent GBS infections and antimicrobial agents susceptibility patterns in China. Routine reports on GBS susceptibilities by clinical laboratories and continuous surveillance for changes in the susceptibility are of considerable clinical importance.