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M antigens among group A streptococci isolated from skin lesions
Abstract:
Three new provisional types of Group A streptococci have been identified among strains isolated from skin infections of American Indian children. A previously established type, Type 41, was also recognized among the pyoderma strains. Most of the skin streptococci with T-agglutination pattern 3/13/B3264 could be identified as Type 41 or as one of two new provisional types, Schoenborn (Type 52) and Hanson (proposed Type 53). Strains of the third new provisional type, Kingbird (proposed Type 54), agglutinated as 15/17/19/23/47, a T pattern not associated with skin infections in studies of other populations. Approximately half of the pyoderma strains examined were found to produce an M antigen; the proportion of M-typable strains from skin infections was found to be similar to that currently found in throat cultures of children with pharyngitis. The demonstration of M antigens in streptococci from skin lesions provides evidence of their potential virulence and should facilitate their classification in subsequent epidemiological studies.
Insights
Three new provisional types of Group A streptococci were identified in skin infections among American Indian children. This study also recognized Type 41 and found M antigens present, indicating potential virulence in these streptococcal strains.
Area of Science:
- Microbiology
- Epidemiology
- Immunology
Background:
- Group A streptococci (GAS) are significant human pathogens.
- Skin infections, particularly pyoderma, are common in certain populations.
- T-agglutination patterns and M antigens are key for classifying GAS strains.
Purpose of the Study:
- To identify and characterize new provisional types of Group A streptococci from skin infections.
- To determine the prevalence of known and new GAS types in this population.
- To investigate the presence of M antigens in skin-infecting GAS strains.
Main Methods:
- Isolation and cultivation of streptococcal strains from skin lesions.
- Serological typing using T-agglutination patterns.
- Identification of M antigens in isolated strains.
Main Results:
- Three new provisional GAS types (Schoenborn, Hanson, Kingbird) were identified.
- Type 41, a previously known type, was also found.
- Approximately 50% of pyoderma strains produced M antigens, similar to pharyngeal strains.
Conclusions:
- New provisional types of Group A streptococci are circulating in American Indian children with skin infections.
- The presence of M antigens suggests these skin isolates possess virulence factors.
- These findings aid in the epidemiological classification and understanding of GAS skin infections.