Distribution, Co-Carriage Patterns, and Applied Biostatistical Analysis of Virulence Determinants in Group B Streptococcus Isolates

An analysis of the distribution and co-occurrence patterns of targeted virulence determinants in Streptococcus agalactiae (Group B Streptococcus; GBS) was conducted. This study employed a cost-efficient methodology that integrates PCR with statistical evaluation to examine the prevalence of virulence genes responsible for adhesion, immune evasion, and toxin activity across 407 GBS isolates. The virulence genes were characterized based on their distribution across various specimen sources, capsular serotypes, and two time periods. A statistical analysis of the virulence patterns was conducted using pairwise odds ratio matrices, facet bar charts, and a multi-annotated matrix, with Benjamini–Hochberg false discovery rate correction, the cophenetic correlation coefficient, and the Davies–Bouldin index applied throughout the process. As a result, we demonstrated the genotypic co-occurrence of genes associated with invasiveness (hvgA, hylB, and PI-2b) and biofilm formation (PI-2a and fbsB), and presented the prevalence of potential vaccine candidates (pilus variants and scpB) alongside specific genes utilized in phenotypic laboratory tests (cfb and cylE). We identified distribution differences across the studied periods and correlations between virulence genes and serotypes. In conclusion, our research demonstrated that the integration of accessible PCR-based screening with advanced statistical analyses offers an approach for virulence surveillance in resource-limited settings.