Related Experiment Video

Updated: May 20, 2026

Intracranial Subarachnoidal Route of Infection for Investigating Roles of Streptococcus suis Biofilms in Meningitis in a Mouse Infection Model
07:26

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

Published on: July 1, 2018

[Capsular saliva acid of Streptococcus suis 2 influences virulence and host inflammatory responses]

Jie Shi1, Dan Hu, Jing Zhu

  • 1Institute of Military Medical Sciences, Nanjing Command, Nanjing 210002, China.

Wei Sheng Wu Xue Bao = Acta Microbiologica Sinica
|July 18, 2012
PubMed
Abstract

Insights

The absence of Streptococcus suis type 2 capsular acid significantly reduces bacterial virulence and inflammation. This capsular acid is crucial for damaging the blood-brain barrier and causing meningitis.

Area of Science:

  • Microbiology
  • Immunology
  • Pathogenesis

Context:

  • Streptococcus suis type 2 is a significant veterinary and zoonotic pathogen.
  • The role of capsular acid in S. suis type 2 virulence is not fully understood.
  • Understanding virulence factors is key to developing effective treatments and prevention strategies.

Purpose:

  • To investigate the pathogenic influence of Streptococcus suis type 2 capsular acid absence in a mouse model.
  • To determine the effect of capsular acid on bacterial virulence, host immune response, and tissue damage.

Summary:

  • Deletion of capsular acid genes in S. suis type 2 significantly reduced bacterial virulence and altered its distribution in vivo.
  • Mutant strains stimulated higher levels of inflammatory cytokines (MCP-1, IL-6) in vitro.
  • Restoration of capsular acid genes recovered virulence and altered cytokine profiles.

Impact:

  • Capsular acid is identified as a critical virulence factor for S. suis type 2.
  • This finding highlights the role of capsular acid in damaging the blood-brain barrier and causing meningitis.
  • The study provides insights into host-pathogen interactions and inflammatory responses during S. suis type 2 infection.

More Related Videos

Opsono-Adherence Assay to Evaluate Functional Antibodies in Vaccine Development Against Bacillus anthracis and Other Encapsulated Pathogens13:47

Opsono-Adherence Assay to Evaluate Functional Antibodies in Vaccine Development Against Bacillus anthracis and Other Encapsulated Pathogens

Published on: May 19, 2020

Capsular Serotyping of Streptococcus pneumoniae by Latex Agglutination09:11

Capsular Serotyping of Streptococcus pneumoniae by Latex Agglutination

Published on: September 25, 2014

Related Concept Videos

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...
Regulation of Bacterial Virulence01:28

Regulation of Bacterial Virulence

Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
Clinical Significance of Antibiotic Resistance01:25

Clinical Significance of Antibiotic Resistance

Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...
Staphylococcal Skin Infections01:29

Staphylococcal Skin Infections

Staphylococcus aureus is a Gram-positive coccus that resides harmlessly on the skin and mucous membranes of healthy individuals. When the skin barrier is breached, it can shift from a commensal to an opportunistic pathogen. This transition is facilitated by surface adhesins, such as clumping factor B and S. aureus surface protein G (SasG), which bind to structural proteins, including loricrin and cytokeratin, in the damaged epidermis. Protein A, another key factor, binds the Fc region of...
Colonisation of Pathogens01:25

Colonisation of Pathogens

Pathogen colonization of host tissues is a critical step in the development of infectious diseases. Various pathogenic microorganisms, including bacteria, fungi, viruses, and protozoa, have evolved complex strategies to attach to, invade, and persist within host environments. These mechanisms enable pathogens to establish infections, evade immune responses, and resist antimicrobial treatments.Attachment to Host CellsIn bacteria, colonization typically begins with adherence to host epithelial...
Formation of Lipopolysaccharides01:19

Formation of Lipopolysaccharides

Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin, triggering...