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Testing meningeal strains of Streptococcus suis to detect M protein genes
J D Mogollon1, C Pijoan, M P Murtaugh
1Department of Clinical and Populations Sciences, College of Veterinary Medicine, University of Minnesota, St Paul 55108.
Abstract:
Previous reports have suggested that the surface proteins found in meningeal strains of Streptococcus suis might be similar to the M protein of group A streptococci. Fifty-five strains of S suis, including human and swine meningeal and pneumonic isolates, were tested for M protein genes by DNA probes representing the constant domain of the 3' end of the group A, M protein gene. None of the S suis strains examined was positive, indicating that these organisms either lack M protein genes or harbour different genes, not expressing the constant domains of protein M from group A.
Insights
Streptococcus suis strains lack M protein genes found in Group A streptococci. This study investigated 55 S. suis isolates, finding no evidence of these specific M protein genes in any strain tested.
Area of Science:
- Microbiology
- Molecular Biology
- Bacteriology
Background:
- Surface proteins of Streptococcus suis, particularly in meningeal strains, have been hypothesized to resemble the M protein of Group A streptococci.
- The M protein is a key virulence factor in Group A streptococci, contributing to their pathogenicity.
Purpose of the Study:
- To investigate the presence of M protein genes in various strains of Streptococcus suis.
- To determine if the M protein gene, specifically the constant domain of the 3' end, is conserved between Group A streptococci and Streptococcus suis.
Main Methods:
- DNA probes targeting the constant domain of the 3' end of the Group A streptococcal M protein gene were utilized.
- Fifty-five strains of Streptococcus suis, encompassing human and swine isolates from meningeal and pneumonic sources, were subjected to genetic analysis using these probes.
Main Results:
- None of the 55 Streptococcus suis strains tested showed a positive signal for the M protein genes.
- This indicates a significant genetic divergence regarding M protein between Streptococcus suis and Group A streptococci.
Conclusions:
- Streptococcus suis lacks the specific M protein genes investigated, as defined by the probes targeting Group A streptococci.
- The findings suggest that Streptococcus suis either does not possess these M protein genes or harbors distinct genes that do not express the conserved domains of Group A streptococcal M protein.