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Characteristics of Streptococcus pyogenes serotype M1 and M3 isolates from patients in Japan from 1981 to 1997
1Department of Bacteriology and Pathology, Kanagawa Prefectural Public Health Laboratory, Yokohama 241-0815, Japan. molamolatm@aol.com
Abstract:
Streptococcus pyogenes isolates obtained in 1981 to 1997 from patients and healthy subjects were characterized by pulsed-field gel electrophoresis (PFGE) patterns, biotyping, and the presence of spe genes encoding streptococcal pyrogenic exotoxins. Changes in the profiles were shown in the serotype M1/T1 isolates from pharyngitis over this period, but not in serotype M3/T3 isolates. The characteristics of isolates from patients with toxic shock-like syndrome (TSLS) were comparable to those of the other isolates, including those from healthy subjects. This finding suggests that further phenotypic and molecular characterization, such as investigating the genomic difference represented by the pathogenicity island, of isolates with apparently the same profiles would be necessary to determine the etiology of diseases caused by S. pyogenes, including TSLS.
Insights
Changes in Streptococcus pyogenes serotype M1/T1 strains were observed between 1981 and 1997, but not in M3/T3 strains. Further genomic analysis is needed to understand the causes of diseases like toxic shock-like syndrome (TSLS).
Area of Science:
- Microbiology
- Molecular Biology
- Epidemiology
Background:
- Streptococcus pyogenes is a significant human pathogen.
- Understanding the evolution and characteristics of S. pyogenes isolates is crucial for public health.
- Previous studies have indicated variability in S. pyogenes strains over time.
Purpose of the Study:
- To characterize Streptococcus pyogenes isolates from 1981 to 1997.
- To investigate changes in specific S. pyogenes serotypes (M1/T1 and M3/T3) over time.
- To compare isolates from patients with toxic shock-like syndrome (TSLS) to other isolates.
Main Methods:
- Pulsed-field gel electrophoresis (PFGE) for DNA fingerprinting.
- Biotyping for phenotypic characterization.
- Detection of spe genes encoding streptococcal pyrogenic exotoxins.
Main Results:
- Serotype M1/T1 isolates from pharyngitis showed changes in PFGE profiles and spe gene presence over the study period.
- Serotype M3/T3 isolates remained stable during the same period.
- Isolates from TSLS patients exhibited characteristics comparable to other S. pyogenes isolates, including those from healthy subjects.
Conclusions:
- Phenotypic and molecular characterization revealed temporal changes in M1/T1 S. pyogenes strains but not M3/T3 strains.
- Isolates from TSLS cases were not distinct from other isolates based on the methods used.
- Further investigation into genomic differences, such as pathogenicity islands, is necessary to elucidate the etiology of S. pyogenes-associated diseases, including TSLS.