Related Experiment Video

Updated: Jun 18, 2026

Development and Assessment of Intracellular Infection Models for Staphylococcus aureus
08:32

Development and Assessment of Intracellular Infection Models for Staphylococcus aureus

Published on: January 17, 2025

Evaluation of capsular and acapsular strains of S. aureus in an experimental brain abscess model

Nilufer Esen1, Gail Wagoner, Napoleon Philips

  • 1Department of Neurology, Holtom-Garrett Program in Neuroimmunology, University of Michigan Medical School, Ann Arbor, MI 48109, United States. nilufer@med.umich.ed

Journal of Neuroimmunology
|November 13, 2009
PubMed

Insights

Staphylococcus aureus (S. aureus) brain abscesses show differing pathogenesis between lab and clinical strains. The acapsular RN6390 strain caused more damage and mortality, while the capsular Reynolds strain induced earlier immune responses.

Area of Science:

  • Neuroscience
  • Infectious Disease
  • Microbiology

Background:

  • Brain abscesses are serious central nervous system infections.
  • Staphylococcus aureus (S. aureus) is a common causative agent.
  • Strain-specific differences in S. aureus pathogenesis are not fully understood.

Purpose of the Study:

  • To compare brain abscess pathogenesis induced by two S. aureus strains: laboratory RN6390 and clinical Reynolds.
  • To investigate the role of S. aureus capsule in virulence and host immune response.

Main Methods:

  • Infection of a host model with RN6390 and Reynolds S. aureus strains.
  • Assessment of parenchymal damage, mortality rates, bacterial proliferation, and immune cell infiltration.
  • Analysis of chemokine (CXCL2), matrix metalloproteinase-9 (MMP-9), and complement (C3a, C5) expression.

Main Results:

  • The acapsular RN6390 strain caused greater parenchymal damage and mortality.
  • The capsular Reynolds strain exhibited faster proliferation and induced earlier CXCL2, MMP-9, C3a, and C5 expression.
  • Reynolds strain led to earlier and more abundant PMN infiltration, T cell presence, and erythrocyte extravasation.

Conclusions:

  • Capsular S. aureus (Reynolds) modulates innate immunity and complement activation differently than acapsular strains (RN6390).
  • Early immune changes induced by the Reynolds strain may significantly impact host survival.
  • Strain-specific virulence factors influence S. aureus brain abscess development and host response.

More Related Videos

Intracranial Subarachnoidal Route of Infection for Investigating Roles of Streptococcus suis Biofilms in Meningitis in a Mouse Infection Model07:26

Intracranial Subarachnoidal Route of Infection for Investigating Roles of Streptococcus suis Biofilms in Meningitis in a Mouse Infection Model

Published on: July 1, 2018

A Mouse Model to Assess Innate Immune Response to Staphylococcus aureus Infection09:15

A Mouse Model to Assess Innate Immune Response to Staphylococcus aureus Infection

Published on: February 28, 2019

Related Concept Videos

Brain Abscess l: Introduction01:26

Brain Abscess l: Introduction

A brain abscess is a focal, intracerebral infection characterized by a localized collection of pus within the brain parenchyma, resulting from microbial invasion and the body’s inflammatory response. It progresses through stages: early and late cerebritis, followed by early and late capsule formation, reflecting tissue destruction, immune response, and eventual encapsulation.Etiology and PathogenesisCausative organisms vary with source and host factors, often involving polymicrobial infections,...
Bacterial Meningitis II: Pathophysiology01:26

Bacterial Meningitis II: Pathophysiology

Bacterial meningitis typically begins when pathogens such as Neisseria meningitidis and Streptococcus pneumoniae colonize the nasopharynx and invade the bloodstream. This process is facilitated by bacterial virulence factors, such as polysaccharide capsules, which resist phagocytosis and complement-mediated killing. Less commonly, bacteria reach the central nervous system via contiguous spread from infections like otitis media or sinusitis, through congenital or acquired dural defects, or...
Bacterial Meningitis I: Introduction01:22

Bacterial Meningitis I: Introduction

Bacterial meningitis is a severe, life-threatening inflammation of the meninges, particularly the pia mater and arachnoid mater, affecting the subarachnoid space, ventricles, and cerebrospinal fluid (CSF). If untreated, it can lead to significant neurological complications or death.Causative AgentsCommon pathogens vary with age and immune status. In adults, major organisms include Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. Streptococcus agalactiae (group B...