Related Experiment Video

Updated: Jan 26, 2026

Quantifying the Cytotoxicity of Staphylococcus aureus Against Human Polymorphonuclear Leukocytes
12:27

Quantifying the Cytotoxicity of Staphylococcus aureus Against Human Polymorphonuclear Leukocytes

Published on: January 3, 2020

6.8K

Necrotizing Soft Tissue Infection Staphylococcus aureus but not S. pyogenes Isolates Display High Rates of

Jessica Baude1, Sylvère Bastien1, Yves Gillet1,2

  • 1Centre International de Recherche en Infectiologie, Université de Lyon; Inserm U1111; Ecole Normale Supérieure de Lyon; Université Lyon 1, CNRS, UMR5308; Lyon, France.

The Journal of Infectious Diseases
|April 20, 2019
PubMed
Abstract

Insights

Staphylococcus aureus (SA) readily invades muscle cells, unlike group A Streptococcus (GAS). This strong invasiveness in muscle cells contributes to the severity of SA necrotizing soft tissue infections (NSTIs).

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Cell Biology

Background:

  • Necrotizing soft tissue infections (NSTIs) often involve deep fascia and muscle necrosis.
  • Group A Streptococcus (GAS) and Staphylococcus aureus (SA) are key causative agents of NSTIs.

Purpose of the Study:

  • To compare the pathogenicity of GAS and SA in muscle cells versus keratinocytes.
  • To investigate the adhesion and invasion mechanisms of NSTI-associated GAS and SA isolates.

Main Methods:

  • Assessed adhesion and invasion of NSTI-GAS and NSTI-SA isolates in human keratinocytes and myoblasts.
  • Utilized bloodstream infection SA (BSI-SA) and coagulase-negative staphylococci (CNS) as controls.
  • Analyzed cytotoxicity, gene transcript levels (psmα, RNAIII), and α5β1 integrin expression.

Main Results:

  • NSTI-SA and BSI-SA showed significantly higher internalization into human myoblasts compared to keratinocytes.
  • S. aureus internalization exceeded 30% in myoblasts, with higher infection rates than in keratinocytes.
  • NSTI-SA exhibited greater myoblast cytotoxicity, linked to elevated psmα and RNAIII transcripts and α5β1 integrin expression.

Conclusions:

  • The strong invasiveness of S. aureus in muscle cells is a key factor in NSTI severity.
  • This muscle cell invasiveness is a characteristic not observed with GAS isolates.
  • The FnbpAB-integrin α5β1 pathway plays a major role in S. aureus internalization into myoblasts.
Keywords:
Staphylococcus aureusStreptococcus pyogenesmuscle cellsnecrotizing soft tissue infections

More Related Videos

Development and Assessment of Intracellular Infection Models for Staphylococcus aureus08:32

Development and Assessment of Intracellular Infection Models for Staphylococcus aureus

Published on: January 17, 2025

1.2K
Improved Enzyme Protection Assay to Study Staphylococcus aureus Internalization and Intracellular Efficacy of Antimicrobial Compounds06:36

Improved Enzyme Protection Assay to Study Staphylococcus aureus Internalization and Intracellular Efficacy of Antimicrobial Compounds

Published on: September 8, 2021

3.2K

Related Concept Videos

Internal Energy02:00

Internal Energy

The total of all possible kinds of energy present in a substance is called the internal energy (U), sometimes symbolized as E. Suppose a system with initial internal energy, Uinitial, undergoes a change in energy (transfer of work or heat), and the final internal energy of the system is Ufinal. Change in internal energy equals the difference between Ufinal and Uinitial.
36.6K
Internal Energy01:29

Internal Energy

The internal energy of a thermodynamic system is the sum of the kinetic and potential energies of all the molecules or entities in the system. The kinetic energy of an individual molecule includes contributions due to its rotation and vibration, as well as its translational energy. The potential energy is associated only with the interactions between one molecule and the other molecules of the system. Neither the system's location nor its motion is of any consequence as far as the internal...
6.9K
Internal Receptors01:31

Internal Receptors

Many cellular signals are hydrophilic and therefore cannot pass through the plasma membrane. However, small or hydrophobic signaling molecules can cross the hydrophobic core of the plasma membrane and bind to internal, or intracellular, receptors that reside within the cell. Many mammalian steroid hormones use this mechanism of cell signaling, as does nitric oxide (NO) gas.
74.4K
Formation of Muscle Fibers from Myoblasts01:13

Formation of Muscle Fibers from Myoblasts

De novo myogenesis, or the formation of muscle fibers, begins during the early embryonic stages. The skeletal muscle is formed from somites– blocks of embryonic cell layers. The somites are further divided into dermatomes, myotomes, sclerotomes, and syndetomes. Among these, the myotomes give rise to muscle fibers.
Muscle progenitor cells (MPCs) are formed from the myotomes. MPCs express genes that encode the transcription factors Pax3 and Pax7. Along with Pax 3/7, other transcription...
5.9K
Speciation Rates01:07

Speciation Rates

Overview
22.7K
Reaction Rate02:53

Reaction Rate

The rate of reaction is the change in the amount of a reactant or product per unit time. Reaction rates are therefore determined by measuring the time dependence of some property that can be related to reactant or product amounts. Rates of reactions that consume or produce gaseous substances, for example, are conveniently determined by measuring changes in volume or pressure.
The mathematical representation of the change in the concentration of reactants and products, over time, is the rate...
62.5K