Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Determinants of Bacterial Pathogenicity and Virulence

Determinants of Bacterial Pathogenicity and Virulence

Pathogenic bacteria employ a variety of strategies to establish infections, including the secretion of extracellular enzymes that act as potent virulence factors. These enzymes facilitate bacterial colonization of host tissues and help evade immune surveillance. By targeting structural components of host tissues and interfering with immune mechanisms, these enzymes play a pivotal role in disease progression.Extracellular Enzymes Facilitating Tissue Invasion: Several bacterial pathogens secrete...

Clinical Significance of Antibiotic Resistance

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...

Streptococcal Pharyngitis

Streptococcal Pharyngitis

Streptococcal pharyngitis, commonly known as “strep throat,” is an acute infection of the oropharyngeal tissues caused by the Gram‑positive Group A Streptococcus (Streptococcus pyogenes). Transmission occurs primarily through respiratory droplets expelled during coughing, sneezing, or talking.Mechanisms of Host Entry and Immune EvasionUpon entering the host, S. pyogenes adheres to the mucosal epithelial cells of the pharynx via surface proteins, notably lipoteichoic acid and the antiphagocytic...

Regulation of Bacterial Virulence

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...

Bacterial Phylum Spirochaetes

Bacterial Phylum Spirochaetes

Spirochetes, unique bacteria in the phylum Spirochaetes, are gram-negative, motile, tightly coiled, slender, and flexible. They inhabit aquatic sediments and animals, with some causing diseases like syphilis. Spirochetes are classified into eight genera based on habitat, pathogenicity, phylogeny, and characteristics.Their distinctive motility arises from endoflagella, located within the cell’s periplasm. These endoflagella anchor at the cell poles and extend along the cell length, encased by a...

Formation of Lipopolysaccharides

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...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Seasonal Influenza Activity, Vaccination Rates, and Pediatric Influenza Mortality, Massachusetts 2024-2025.

NEJM evidence·2026

Same author

Serotype specific pneumococcal vaccine effectiveness in children with sickle cell disease: A two-decade analysis.

Vaccine·2025

Same author

Geospatial and demographic patterns of SARS-CoV-2 spread in Massachusetts from over 130,000 genomes.

medRxiv : the preprint server for health sciences·2025

Same author

JUNIPER: Reconstructing Transmission Events from Next-Generation Sequencing Data at Scale.

Research square·2025

Same author

Establishing Methods to Monitor Influenza (A)H5N1 Virus in Dairy Cattle Milk, Massachusetts, USA.

Emerging infectious diseases·2025

Same author

JUNIPER: Reconstructing Transmission Events from Next-Generation Sequencing Data at Scale.

medRxiv : the preprint server for health sciences·2025

Search research articles

Related Experiment Video

Updated: Jun 28, 2026

A Murine Model of Group B Streptococcus Vaginal Colonization

A Murine Model of Group B Streptococcus Vaginal Colonization

Published on: November 16, 2016

Lactic acid is a potential virulence factor for group B Streptococcus.

David E Kling¹, Amanda J Cavicchio, Christina A Sollinger

¹Laboratory of Developmental Immunology, Department of Pediatrics, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, GRJ 1402, Boston, MA 02114, USA. dkling@partners.org

Microbial Pathogenesis

|November 18, 2008

Summary

Group B Streptococcus (GBS) produces high levels of lactic acid, a potent virulence factor. This acid contributes to tissue damage, potentially explaining GBS invasive disease mechanisms in infants.

More Related Videos

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria

Published on: February 23, 2014

Related Experiment Videos

Last Updated: Jun 28, 2026

A Murine Model of Group B Streptococcus Vaginal Colonization

A Murine Model of Group B Streptococcus Vaginal Colonization

Published on: November 16, 2016

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria

Published on: February 23, 2014

Area of Science:

Microbiology
Pathogenesis
Bacterial Virulence Factors

Background:

Group B Streptococcus (GBS) causes serious infections like sepsis and meningitis in newborns.
The precise mechanisms behind GBS invasive disease remain incompletely understood.
Existing knowledge of GBS virulence factors is limited.

Purpose of the Study:

To investigate novel virulence factors of Group B Streptococcus (GBS).
To characterize the role of metabolic byproducts in GBS pathogenesis.
To understand the contribution of GBS-derived substances to tissue damage.

Main Methods:

Development of a novel in vitro rat fetal lung explant infection model.
Application of GBS spent growth media and neutralized media to lung explants.
Utilized viability assays and transformed cell lines for verification.
Analyzed spent media for organic acid content, specifically l-lactate.

Main Results:

GBS application to lung explants caused rapid tissue destruction linked to media acidity.
Neutralizing the spent media completely prevented tissue degradation.
High levels of l-lactate (approx. 70 mM) were detected in GBS spent media.
Lactic acid alone induced dose-dependent tissue degradation, confirming its cytotoxic effect.

Conclusions:

GBS-produced lactic acid functions as a significant virulence factor.
Lactic acid contributes to the cytotoxicity observed in GBS infections.
This finding offers new insights into the mechanisms of GBS invasive disease in neonates.