Related Experiment Video
Updated: Mar 12, 2026
07:10
A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues
Published on: February 19, 2019
9.6K
Evolutionary dynamics and virulence factor variability in invasive Streptococcus pyogenes in Norway, 2017-2023
Ola Brønstad Brynildsrud1, Hilde S Vollan Gjerdrum1, Einar Sverre Berg2
1Department of Method Development and Analytics, Division of Infection Control, Norwegian Institute of Public Health, Oslo, Norway.
Msphere
|March 11, 2026
Summary
Invasive Group A Streptococcus (iGAS) infections in Norway increased due to evolving bacterial strains carrying new virulence factors. Researchers identified dynamic phage activity and antibiotic resistance patterns, highlighting the need for ongoing surveillance of these dangerous pathogens.
Area of Science:
- Microbiology
- Epidemiology
- Genomics
Background:
- Invasive Group A Streptococcus (iGAS) infections have risen in Europe, particularly post-COVID-19.
- Understanding the genetic factors driving this increase is crucial for public health.
Purpose of the Study:
- To investigate the association between increased iGAS incidence in Norway and the acquisition of new virulence factors by bacterial variants.
- To analyze the genomic characteristics, antibiotic resistance, and virulence factor content of iGAS isolates.
Main Methods:
- Whole genome sequencing of 1,163 iGAS isolates collected between January 2017 and April 2023.
- Analysis of antibiotic resistance profiles and virulence factor genes, including temperate phages.
Main Results:
- 15.6% of iGAS isolates showed resistance to at least one antibiotic; tetracycline resistance was most prevalent.
- Dominant emm types included emm1 (30.9%), emm12 (13.8%), and emm89 (9.3%).
- Significant dynamic turnover of temperate phages carrying virulence factors speC and spd1 was observed, with four new phages identified.
Conclusions:
- The increase in iGAS infections in Norway is linked to the spread of variants with acquired virulence factors, particularly those involving dynamic phage activity.
- Continuous surveillance of emm types, antibiotic resistance, and virulence factors is essential for managing iGAS epidemiology.
More Related Videos
Related Concept Videos
01:26Factors Affecting the Risk of Infection
14.4K
The hosts' susceptibility to infection depends on several factors. The integrity of the skin and mucous membranes helps protect the body against microbial attacks. When the skin is altered, the chance of infection, limb loss, and even death increases.
The integrity and count of the white blood cells help the body resist pathogens and fight infection. When impaired, it reduces the body's resistance to pathogens. The acidic pH levels of the gastrointestinal, genitourinary tracts, and skin...
The integrity and count of the white blood cells help the body resist pathogens and fight infection. When impaired, it reduces the body's resistance to pathogens. The acidic pH levels of the gastrointestinal, genitourinary tracts, and skin...
14.4K
01:09Mutation, Gene Flow, and Genetic Drift
65.5K
In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).
65.5K
01:16Transduction
2.3K
Among the three main modes of HGT—transformation, conjugation, and transduction—transduction is unique in that it is mediated by bacteriophages, or bacterial viruses.Transduction occurs in two ways. Generalized transduction occurs during the lytic cycle of a bacteriophage infection. In this process, bacteriophages infect bacterial cells, replicate within them, and ultimately cause cell lysis, releasing newly assembled virions. Occasionally, random fragments of the bacterial genome...
2.3K
02:05Gene Evolution - Fast or Slow?
8.3K
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
8.3K
01:31Defense Against Bacterial Pathogens
3.3K
The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
3.3K
03:33Genetic Drift
44.8K
Natural selection—probably the most well-known evolutionary mechanism—increases the prevalence of traits that enhance survival and reproduction. However, evolution does not merely propagate favorable traits, nor does it always benefit populations.
44.8K