Bacterial growth comparison of vaccine and non-vaccine type Streptococcus pneumoniae in different enrichment broths

Broth enrichment is used to enhance pneumococcal carriage detection. Identifying serotypical growth difference during enrichment can prevent detection biases. We discovered, using supplemented Todd-Hewitt broth (0.5% yeast extract) at 4-h incubation and supplemented Brain Heart Infusion broth at 5-h incubation, provide no significant growth difference between vaccine and non-vaccine types. •Broth enrichment is used to enhance pneumococcal carriage detection.•No difference in growth between VT and NVT In THYS at the 4-h incubation.•No difference in growth between VT and NVT In BHIS at the 5-h incubation.•The enrichment broth and incubation period are key factors in the enrichment step.