Streptococcal emm types associated with T-agglutination types and the use of conserved emm gene restriction fragment

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Genotyping of Staphylococcus aureus by Ribosomal Spacer PCR (RS-PCR)
08:51

Genotyping of Staphylococcus aureus by Ribosomal Spacer PCR (RS-PCR)

Published on: November 4, 2016

B Beall1, R R Facklam, J A Elliott

  • 1Centers for Disease Control and Prevention, Childhood and Respiratory Infections, Atlanta, GA 30333, USA.

Journal of Medical Microbiology
|October 27, 1998
PubMed

Insights

Group A Streptococcus T-agglutination typing was correlated with M protein gene (emm) sequencing. New associations were identified, aiding in the molecular epidemiology of Streptococcus pyogenes strains.

Area of Science:

  • Microbiology
  • Molecular Epidemiology
  • Bacteriology

Background:

  • Group A Streptococcus (GAS) is a significant human pathogen.
  • M protein gene (emm) sequencing is a key tool for GAS typing.
  • T-agglutination typing is a traditional method for GAS classification.

Purpose of the Study:

  • To correlate T-agglutination types with 5' M protein gene (emm) sequences in a large collection of Group A Streptococcus isolates.
  • To identify novel associations between T-types and emm types.
  • To evaluate the utility of emm amplicon restriction profiles for grouping isolates with identical emm genes.

Main Methods:

  • Determination of T-agglutination types for 1531 Group A Streptococcus isolates.
  • Analysis of 5' M protein gene (emm) sequences for the same isolates.
  • Restriction profiling of emm amplicons from a subset of clinical isolates.
  • Phenotypic characterization including opacity factor analysis.

Main Results:

  • A majority of T-agglutination types showed previously established correlations with M/emm/T-type associations.
  • Several novel associations between T-agglutination types and emm types were discovered.
  • emm amplicon restriction profiles effectively grouped isolates with identical emm genes, T types, and opacity factor phenotypes.
  • A conserved restriction pattern was observed for many emm genes across geographically and temporally diverse clinical isolates.

Conclusions:

  • T-agglutination typing remains a valuable adjunct to emm sequencing for characterizing Group A Streptococcus.
  • emm amplicon restriction profiling offers a practical method for identifying genetically related isolates.
  • The conserved nature of emm restriction patterns supports their use in molecular surveillance of GAS.

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