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Molecular markers for throat and skin isolates of group A streptococci
D E Bessen1, T R Fiorentino, S K Hollingshead
1Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, Connecticut, USA.
Abstract:
In summary, the emm chromosomal patterns distinguish between the two principal tissue site reservoirs of group A streptococci--the nasopharyngeal mucosa and impetigo lesion. Strains derived from normally sterile tissue sites are probably transmitted to new hosts by respiratory droplets, at least in the Connecticut population. The speA gene provides an example of how genetic exchange between different strains of group A streptococci may be limited to a single tissue site or to a subset of emm chromosomal patterns.
Insights
emm chromosomal patterns differentiate group A streptococci reservoirs in the nasopharynx and skin. Genetic exchange of the speA gene in group A streptococci may be site-specific, impacting strain evolution.
Area of Science:
- Microbiology
- Genetics
- Epidemiology
Background:
- Group A Streptococcus (GAS) resides in distinct human tissue sites, including the nasopharynx and skin.
- Understanding GAS reservoirs and transmission is crucial for controlling infections.
Purpose of the Study:
- To investigate the relationship between emm chromosomal patterns and the primary tissue sites of group A streptococci.
- To explore the transmission routes and genetic exchange patterns of GAS.
Main Methods:
- Analysis of emm chromosomal patterns from GAS isolates from different tissue sites.
- Epidemiological investigation of transmission routes, including respiratory droplets.
- Examination of the speA gene for evidence of genetic exchange.
Main Results:
- Distinct emm chromosomal patterns were identified for nasopharyngeal and impetigo lesion isolates.
- Strains from sterile sites were likely transmitted via respiratory droplets in the Connecticut population.
- The speA gene demonstrated limited genetic exchange, potentially restricted to specific tissue sites or emm patterns.
Conclusions:
- emm chromosomal patterns serve as markers for differentiating GAS tissue site reservoirs.
- Respiratory droplet transmission is a significant route for GAS from sterile sites.
- Tissue site specificity may influence genetic exchange within GAS populations, impacting strain diversity.