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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

A multiple drug-resistant Streptococcus pneumoniae of serotype 15A occurring from serotype 19A by capsular switching

T Savinova1, E Brzhozovskaya1, D Shagin2

  • 1National Medical Research Center for Children's Health, Lomonosovskiy av., 2a, Moscow, Russia.

Vaccine
|June 23, 2020
PubMed

Insights

A new multidrug-resistant Streptococcus pneumoniae strain emerged through capsular switching. This discovery highlights the need for ongoing surveillance of pneumococcal serotype and genotype structures to track resistant strains.

Area of Science:

  • Microbiology
  • Genetics
  • Epidemiology

Background:

  • Streptococcus pneumoniae is a significant human pathogen.
  • Pneumococci exhibit high genetic recombination, facilitating adaptation to medical treatments.
  • Acquisition of foreign DNA is a key evolutionary driver for this bacterium.

Purpose of the Study:

  • To investigate the genetic mechanisms behind the emergence of drug-resistant pneumococcal strains.
  • To identify novel serotypes and genotypes of multidrug-resistant Streptococcus pneumoniae.
  • To assess the evolutionary dynamics of pneumococcal adaptation to antibiotics and vaccines.

Main Methods:

  • Whole genome sequencing was employed to analyze the genetic makeup of the identified pneumococcal isolate.
  • Comparative genomic analysis was performed to identify genetic alterations, including capsular switching.
  • Phylogenetic analysis was used to trace the evolutionary origin of the resistant strain.

Main Results:

  • A multidrug-resistant serotype 15A Streptococcus pneumoniae strain was identified.
  • This strain resulted from capsular switching, originating from a serotype 19A/ST276 lineage.
  • The findings indicate the successful emergence and potential dissemination of recombinant, drug-resistant pneumococci with non-vaccine serotypes.

Conclusions:

  • Capsular switching is a significant mechanism for the emergence of multidrug-resistant Streptococcus pneumoniae.
  • The spread of these recombinant, non-vaccine type strains poses a public health concern.
  • Continuous monitoring of pneumococcal serotype and genotype is crucial for effective disease control and public health strategies.
Keywords:
Capsular switchingMultiple drug-resistant pneumococcusSerotype 15AStreptococcus pneumoniae

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