Sequence Diversity within the Capsular Genes of Streptococcus pneumoniae Serogroup 6 and 19
2011

Diversity in Pneumococcal Capsular Genes

Sample size: 184 publication Evidence: moderate

Author Information

Author(s): Elberse Karin, Witteveen Sandra, van der Heide Han, van de Pol Ingrid, Schot Corrie, van der Ende Arie, Berbers Guy, Schouls Leo

Primary Institution: National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands

Hypothesis

The study aims to investigate the sequence diversity of the capsular genes of Streptococcus pneumoniae serotypes 6 and 19 and explore the effect of vaccination on these variations.

Conclusion

The study found considerable DNA sequence variation in the capsular genes of pneumococcal serogroups 6 and 19, which may affect vaccine sensitivity.

Supporting Evidence

  • Six distinct capsular subtypes were identified within serotype 6A.
  • Capsular subtype 19A-I accounted for 41% of serotype 19A isolates in the pre-vaccination period.
  • Shifts in capsular subtypes were observed after the introduction of the 7-valent pneumococcal vaccine.

Takeaway

Scientists looked at the genes that help bacteria make their protective coating and found a lot of differences, which could make some bacteria harder to fight with vaccines.

Methodology

The complete capsular gene locus was sequenced for 25 serogroup 6 and 20 serogroup 19 isolates, and allele-specific PCRs were performed on 184 serogroup 6 and 195 serogroup 19 isolates to identify capsular subtypes.

Limitations

The study's findings on capsular subtype shifts post-vaccination were not statistically significant.

Participant Demographics

Isolates were collected from patients with invasive pneumococcal disease in the Netherlands.

Digital Object Identifier (DOI)

10.1371/journal.pone.0025018

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