Related Experiment Video

Updated: May 5, 2026

Measuring Bacterial Load and Immune Responses in Mice Infected with Listeria monocytogenes
12:50

Measuring Bacterial Load and Immune Responses in Mice Infected with Listeria monocytogenes

Published on: August 9, 2011

31.2K

EⅡB Mutation Reduces the Pathogenicity of Listeria monocytogenes by Negatively Regulating Biofilm Formation Ability,

Caixia Liu1, Ruixuan Qian1, Weidi Shi1

  • 1College of Animal Science and Technology, Shihezi University, Shihezi 832000, China.

Veterinary Sciences
|July 26, 2024
PubMed

Insights

The membrane permease IIB (EIIB) gene deletion in Listeria monocytogenes reduced its virulence and biofilm formation. This EIIB gene plays a key role in Listeria pathogenicity.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Pathogenesis

Background:

  • Listeria monocytogenes is a significant foodborne pathogen.
  • The Listeria pathogenicity island 4 (LIPI-4) is crucial for L. monocytogenes virulence.
  • The specific role of the EIIB gene within LIPI-4 requires further elucidation.

Purpose of the Study:

  • To investigate the function of the membrane permease IIB (EIIB) gene from LIPI-4 in L. monocytogenes virulence.
  • To assess the impact of EIIB deletion on bacterial behavior in vitro and in vivo.

Main Methods:

  • Construction of an EIIB deletion strain (ΔEIIB) and a complemented strain.
  • In vitro assays for biofilm formation and intracellular proliferation.
  • In vivo infection model using mice to evaluate survival, weight loss, bacterial load, and cytokine levels.
  • Transcriptomic analysis to identify gene expression changes post-EIIB deletion.

Main Results:

  • EIIB deletion significantly impaired biofilm formation and intracellular proliferation of L. monocytogenes.
  • Mice infected with ΔEIIB showed increased survival rates and reduced weight loss.
  • Reduced bacterial load in liver tissue and decreased inflammatory cytokine levels (IL-1β, IL-6, IL-10, TNF-α) were observed in ΔEIIB infected mice.
  • Gene expression analysis revealed widespread downregulation of virulence and biofilm-related genes following EIIB deletion.

Conclusions:

  • The EIIB gene is essential for L. monocytogenes virulence and biofilm formation.
  • EIIB deletion attenuates L. monocytogenes pathogenicity both in vitro and in vivo.
  • Downregulation of virulence and biofilm genes is a key mechanism by which EIIB deletion reduces pathogenicity.
Keywords:
LIPI-4adhesioninflammatory cytokinesintracellular proliferationinvasion

More Related Videos

Oral Transmission of Listeria monocytogenes in Mice via Ingestion of Contaminated Food08:38

Oral Transmission of Listeria monocytogenes in Mice via Ingestion of Contaminated Food

Published on: May 6, 2013

19.3K
Experimental Infection with Listeria monocytogenes as a Model for Studying Host Interferon-γ Responses10:10

Experimental Infection with Listeria monocytogenes as a Model for Studying Host Interferon-γ Responses

Published on: November 16, 2016

13.6K

Related Concept Videos

Gene Regulation in Microbial Communities: Quorum Sensing01:28

Gene Regulation in Microbial Communities: Quorum Sensing

Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
954
Stringent Response in E. coli01:23

Stringent Response in E. coli

Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
528
Mutations in Microorganisms01:18

Mutations in Microorganisms

Mutations are heritable changes in an organism’s genome involving alterations in the base sequence of DNA or RNA. These changes can influence cellular processes and phenotypic traits, potentially transforming the unaltered wild type into a mutant form. Such changes, termed forward mutations, are pivotal in shaping the genetic diversity of organisms.RNA viruses exhibit the highest mutation rates due to the absence of robust proofreading mechanisms during genome replication. In contrast,...
1.2K
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...
76
Bacterial Gastroenteritis01:18

Bacterial Gastroenteritis

Bacterial gastroenteritis, characterized by diarrhea, abdominal cramps, and vomiting, is often caused by ingestion of contaminated food or water and is frequently associated with pathogenic Escherichia coli strains. These microbes exploit two principal mechanisms to inflict disease.Shiga toxin–producing E. coli, also referred to as STEC—notably O157:H7—release Shiga toxins that target ribosomes, blocking protein synthesis. The B subunit of the toxin binds the host glycolipid...
88
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...
90