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Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus
09:03

Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus

Published on: September 5, 2013

Array of M protein gene subtypes in 1064 recent invasive group A streptococcus isolates recovered from the active

Zhongya Li1, Varja Sakota, Delois Jackson

  • 1Division of Bacterial and Mycotic Diseases, Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.

The Journal of Infectious Diseases
|November 19, 2003
PubMed

Insights

Group A Streptococcus (GAS) M protein analysis revealed 41 emm types and 81 subtypes in invasive isolates. Limited variation within types suggests M protein vaccines could be effective.

Area of Science:

  • Microbiology
  • Genetics
  • Epidemiology

Background:

  • Group A Streptococcus (GAS) is a significant human pathogen.
  • The M protein is a key virulence factor and target for vaccine development.
  • Understanding M protein diversity is crucial for effective vaccine strategies.

Purpose of the Study:

  • To analyze the genetic variation of the M protein N terminus in invasive GAS isolates.
  • To determine the prevalence of different emm types and subtypes in a recent surveillance study.
  • To assess the potential for developing M protein type-specific vaccines.

Main Methods:

  • Sequence analysis of the hypervariable M protein N terminus.
  • Analysis of 1064 consecutive invasive GAS isolates from a multistate surveillance.
  • Comparison of identified emm sequences with the Centers for Disease Control and Prevention (CDC) database.

Main Results:

  • Identified 41 emm types and 81 subtypes among the invasive GAS isolates.
  • Found that 17 of 30 emm types with multiple isolates exhibited multiple subtypes.
  • Observed that most subtype variations resulted from single base substitutions, suggesting stable inheritance.

Conclusions:

  • The M protein N terminus exhibits significant diversity, with numerous emm types and subtypes identified.
  • The observed variations are largely stable, supporting their use as specific targets.
  • Limited variation within individual emm types favors the development of M protein type-specific vaccines.

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