Related Experiment Videos
Group A streptococcal Vir types are M-protein gene (emm) sequence type specific
D L Gardiner1, A M Goodfellow, D R Martin
1Menzies School of Health Research, Darwin, Australia. don@menzies.su.edu.au
Journal of Clinical Microbiology
|May 23, 1998
Summary
Sequencing Streptococcus pyogenes M-protein (emm) genes revealed new types and confirmed Vir typing accuracy. This study enhances understanding of emm gene diversity in impetigo isolates.
Area of Science:
- Microbiology
- Genetics
- Molecular Biology
Background:
- Streptococcus pyogenes causes impetigo and other skin infections.
- M-protein genes (emm) are key virulence factors and targets for typing.
- Vir typing, a restriction fragment length polymorphism (RFLP) method, is used for S. pyogenes classification.
Purpose of the Study:
- To sequence emm genes from impetiginous S. pyogenes isolates.
- To compare emm sequence types with existing Vir typing results.
- To identify novel emm sequence types and understand their genetic diversity.
Main Methods:
- Sequencing of emm genes from 103 S. pyogenes isolates.
- Vir typing using RFLP analysis of a pathogenicity island with HaeIII and HinfI restriction enzymes.
- Comparison of obtained emm sequences with GenBank database.
Main Results:
- Complete concordance was observed between Vir type and emm sequence type.
- New emm sequence types were identified, showing less than 90% identity to known types.
- Genetic diversity in emm sequences resulted from frameshift, point, and in-frame mutations.
Conclusions:
- emm gene sequencing is a reliable method for S. pyogenes typing, correlating with Vir typing.
- The study identified novel emm types, expanding the known genetic diversity of S. pyogenes.
- Understanding emm gene mutations provides insights into bacterial evolution and virulence.