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Updated: May 19, 2026

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction
04:25

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction

Published on: February 24, 2014

Global mapping of Streptococcus pneumoniae sequence types associated with multidrug resistance and capsular

Samuel A Akwetey1, Akosua B Karikari2, Onyasaniba K Ntim3

  • 1Department of Medical Microbiology, University of Ghana Medical School, Accra, Ghana; Department of Clinical Microbiology, School of Medicine, University for Development Studies, Tamale, Ghana.

Infection, Genetics and Evolution : Journal of Molecular Epidemiology and Evolutionary Genetics in Infectious Diseases
|May 17, 2026
PubMed
Abstract

Insights

Streptococcus pneumoniae evolves rapidly through capsular switching, leading to multidrug resistance (MDR). This review highlights key MDR sequence types and switching events, emphasizing the need for ongoing genomic surveillance post-vaccine introduction.

Area of Science:

  • Microbiology
  • Genomics
  • Epidemiology

Background:

  • Streptococcus pneumoniae causes significant invasive and non-invasive infections.
  • Capsular switching in S. pneumoniae contributes to multidrug resistance (MDR) and difficult-to-treat infections.

Purpose of the Study:

  • To systematically review sequence types of S. pneumoniae associated with MDR and/or capsular switching.
  • To analyze the genetic relatedness of these sequence types.

Main Methods:

  • Systematic review following PRISMA guidelines.
  • Comprehensive literature search of PubMed, Scopus, and Web of Science (1991-2024).
  • Screening of studies documenting sequence types linked to MDR and/or capsular switching.

Main Results:

  • Identified dominant MDR sequence types: ST177, ST63, ST199, ST156, ST242, and ST338.
  • Compiled 390 capsular switching events across 184 sequence types globally.
  • Observed trends of switching from vaccine to non-vaccine serotypes, especially post-vaccination.

Conclusions:

  • MDR S. pneumoniae lineages diversify via capsular switching and serotype replacement.
  • Vaccine-type MDR clones persist post-Pneumococcal Conjugate Vaccine (PCV) introduction, concerning serotypes 3, 6A/B, 19F, 14, and 23F.
  • ST320 and ST271 are potential new Pneumococcal Molecular Epidemiology Network (PMEN) clone candidates, necessitating continued genomic surveillance.
Keywords:
Capsular switchingMultidrug resistancePMEN clonesSequence typesStreptococcus pneumoniae

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