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Updated: Feb 19, 2026
Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43
Published on: September 11, 2020
Genomic Comparison among Lethal Invasive Strains of Streptococcus pyogenes Serotype M1
Gabriel R Fernandes1, Aulus E A D Barbosa1, Renan N Almeida1
1Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, Brazil.
Abstract:
Streptococcus pyogenes, also known as group A Streptococcus (GAS), is a human pathogen that causes diverse human diseases including streptococcal toxic shock syndrome (STSS). A GAS outbreak occurred in Brasilia, Brazil, during the second half of the year 2011, causing 26 deaths. Whole genome sequencing was performed using Illumina platform. The sequences were assembled and genes were predicted for comparative analysis with emm type 1 strains: MGAS5005 and M1 GAS. Genomics comparison revealed one of the invasive strains that differ from others isolates and from emm 1 reference genomes. Also, the new invasive strain showed differences in the content of virulence factors compared to other isolated in the same outbreak. The evolution of contemporary GAS strains is strongly associated with horizontal gene transfer. This is the first genomic study of a Streptococcal emm 1 outbreak in Brazil, and revealed the rapid bacterial evolution leading to new clones. The emergence of new invasive strains can be a consequence of the injudicious use of antibiotics in Brazil during the past decades.
Insights
Group A Streptococcus (GAS) caused a deadly 2011 outbreak in Brazil. Genomic analysis revealed rapid evolution and new invasive clones, possibly linked to antibiotic use.
Area of Science:
- Microbiology
- Genomics
- Epidemiology
Background:
- Streptococcus pyogenes, or group A Streptococcus (GAS), is a significant human pathogen.
- GAS causes severe diseases, including streptococcal toxic shock syndrome (STSS).
- A notable GAS outbreak occurred in Brasilia, Brazil, in 2011, resulting in 26 fatalities.
Purpose of the Study:
- To conduct the first genomic investigation of a Streptococcus pyogenes emm type 1 outbreak in Brazil.
- To analyze the genetic makeup of invasive GAS strains from the 2011 outbreak.
- To compare these strains with existing emm type 1 reference genomes and identify evolutionary patterns.
Main Methods:
- Whole genome sequencing utilizing the Illumina platform.
- Sequence assembly and gene prediction.
- Comparative genomics analysis against reference strains MGAS5005 and M1 GAS.
Main Results:
- Genomic comparison identified an invasive strain distinct from other outbreak isolates and reference emm 1 genomes.
- This novel invasive strain exhibited variations in virulence factor content compared to other strains from the same outbreak.
- Evidence suggests rapid bacterial evolution and the emergence of new GAS clones.
Conclusions:
- The evolution of contemporary GAS strains is significantly influenced by horizontal gene transfer.
- This study highlights the emergence of new, potentially more invasive, Streptococcus pyogenes clones in Brazil.
- The rise of these new invasive strains may be associated with historical patterns of antibiotic misuse in Brazil.
