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[A study of the antigenicity of group A streptococcus strain "Matsuyama 2166" and its prevalence]
Abstract:
Antigen analysis of group A streptococcus strain, "Matsuyama 2166", which had been typed as T12-28 (by the T-agglutination method), MNT (nontypeable by the M-precipitation method) using conventional typing sera was examined by the precipitation and precipitation absorption technique. The prevalence of group A streptococci, typed under the name "Matsuyama 2166" was also investigated. The results were as follows: 1) The strain "Matsuyama 2166" is OF (Opacity Factor) (+) and its serological components consist of M "Matsuyama 2166" antigen, which is unique in our collection of M-types, and T28 antigen as a major antigen along with T12 as a minor. 2) Out of the group A streptococci typed as MNT, 96.6% of the streptococci were types as T12-28 and 96.5% of T28 by conventional typing sera were strains to be typed as M "Matsuyama 2166" using the newly prepared M "Matsuyama 2166" typing serum, suggesting the great advantage to M-typing rate of T28 strains. 3) Group A streptococcus M "Matsuyama 2166" was also found in isolates from Thailand or Malaysia. It is interesting that T-types found in those isolates seems to be a little different from the T-types isolated in Japan. These results showed that there was the difficult problem when we did the speculation of M-type from the result of T-type.
Insights
A novel Group A Streptococcus antigen, M "Matsuyama 2166", was identified. This antigen improves typing accuracy for T28 strains, aiding in the identification of Group A Streptococcus prevalence globally.
Area of Science:
- Microbiology
- Immunology
- Bacteriology
Context:
- Group A Streptococcus (GAS) typing is crucial for epidemiological surveillance.
- Conventional M-precipitation and T-agglutination methods have limitations in accurately typing all GAS strains.
- The "Matsuyama 2166" strain was previously typed as T12-28 and nontypeable (MNT) by standard methods.
Purpose:
- To analyze the antigenic composition of the Group A Streptococcus strain "Matsuyama 2166".
- To investigate the prevalence of Group A Streptococcus strains, specifically those related to "Matsuyama 2166".
- To evaluate the efficacy of a newly prepared M "Matsuyama 2166" typing serum.
Summary:
- The "Matsuyama 2166" strain possesses a unique M antigen (M "Matsuyama 2166") and major T28 antigen.
- A new M "Matsuyama 2166" typing serum significantly improved the M-typing rate for T28 strains, with 96.6% of MNT strains and 96.5% of T28 strains being successfully typed.
- The M "Matsuyama 2166" antigen was detected in isolates from Thailand and Malaysia, though with potentially different T-types compared to Japanese isolates.
Impact:
- The study highlights the utility of the M "Matsuyama 2166" antigen and its corresponding serum in enhancing the accuracy of Group A Streptococcus M-typing, particularly for T28 strains.
- This improved typing method has implications for more precise epidemiological tracking of Group A Streptococcus globally.
- The findings underscore the complexity of inferring M-types solely from T-type results, emphasizing the need for comprehensive antigenic analysis.