GBS-SBG

GBS-SBG assigns serotypes to Group B Streptococcus (Streptococcus agalactiae) from whole-genome sequencing data to support epidemiological surveillance and vaccine-related analyses.

Key Features:

• Comprehensive serotype database: Includes reference sequences covering all currently described GBS serotypes, including subtypes of serotype III.
• Read- and assembly-based typing: Supports direct short-read-based typing and assembly-based typing from WGS data.
• Automated calling scripts: Provides scripts to call serotypes from sequence data.
• Validation on reported strains: Demonstrated higher concordance than existing WGS-based methods in a study of 790 previously reported strains.
• Independent validation with PCR concordance: Achieved 99.8% concordance with PCR-based molecular serotyping in an independent validation of 572 strains.
• WGS compatibility: Designed specifically for whole-genome sequencing–based serotyping workflows.
• Validation data reference: WGS data for the 572-isolate validation set are available under Bioproject PRJNA293392 at NCBI.

Scientific Applications:

• Epidemiological surveillance: Determination of capsular serotype distributions for population-level surveillance and outbreak tracking.
• Vaccine development and evaluation: Capsular polysaccharide-based serotyping to inform antigen selection and monitor vaccine impact.
• Clinical and public health investigations: Serotype characterization of isolates associated with neonatal meningitis, adult sepsis, and foodborne disease investigations.
• Method comparison and validation: Comparative assessment of WGS-based serotyping against PCR-based molecular serotyping.

Methodology:

Uses a comprehensive GBS capsular polysaccharide reference database and accompanying scripts to call serotypes from either raw short reads or assembled genome sequences (short-read-based and assembly-based typing).