serotype, genotype, and clinical manifestations of group b streptococcus (gbs) isolated from neonates in china

Background: group b streptococcus (gbs) is a common bacterial pathogen causing nenatal infections. this study aimed to determinethe serotypesandgenotypes of gbsisolated from neonatesandto ascertain the association between the typeandthe antibiotic resistance of gbs strains. methods: a total of 26 group b streptococcus (gbs) strains were isolated from neonates in our hospital between january, 2008 and august, 2014. species identification was conducted with a vitek system (biomerieux) and conventional biochemical tests. a latex agglutination test was used to determine the serotypes of the gbs strains. the antibiotic resistance of gbs strains was then evaluated using a kirby-bauer disk susceptibility test and an epsilometer test (e-test). multilocus sequence typing (mlst) was used to determine the sequence types (sts) of all 26 gbs strains. results and conclusions: serotype iii and sequence type st17 were the major gbs strain serotype and genotype causing invasive infections in neonates, respectively. these gbs strains exhibited a high rate of resistance to tetracycline, erythromycin, and clindamycin, confirming that penicillin should remain the first-line antibiotic for the treatment of gbs infection. in addition, we identifiedanassociationbetweenserotype iiiandgenotype st17 with septicaemia, purulent meningitisandpneumoniaingbsinfections in neonates.