Related Experiment Video

Updated: Feb 28, 2026

A Visual Assay to Monitor T6SS-mediated Bacterial Competition
08:45

A Visual Assay to Monitor T6SS-mediated Bacterial Competition

Published on: March 20, 2013

16.2K

Shigella sonnei Encodes a Functional T6SS Used for Interbacterial Competition and Niche Occupancy

Mark C Anderson1, Pascale Vonaesch1, Azadeh Saffarian1

  • 1Institut Pasteur, Unité de Pathogénie Microbienne Moléculaire, 75724 Paris, France; Unité 1202, INSERM, U1202, 75015 Paris, France.

Cell Host & Microbe
|June 16, 2017
PubMed

Insights

Shigella sonnei increasingly causes dysentery due to its type VI secretion system (T6SS), which grants a competitive edge over Shigella flexneri in the gut and in mouse models.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Bacterial Pathogenesis

Background:

  • Shigella species are major causes of bacterial dysentery globally.
  • Shigella sonnei is increasingly prevalent, displacing Shigella flexneri, but the reasons are unclear.

Purpose of the Study:

  • To investigate the mechanisms underlying the increasing global prevalence of Shigella sonnei.
  • To determine if Shigella sonnei possesses a competitive advantage over Shigella flexneri.

Main Methods:

  • Comparative analysis of Shigella sonnei and Shigella flexneri genomes for unique virulence factors.
  • In vitro competition assays using mixed bacterial cultures.
  • In vivo competition and persistence studies in a mouse model.

Main Results:

  • Shigella sonnei encodes a type VI secretion system (T6SS), unlike Shigella flexneri.
  • The T6SS in Shigella sonnei confers a competitive advantage against E. coli and Shigella flexneri in vitro.
  • Shigella sonnei demonstrates T6SS-dependent persistence and competitive success against E. coli and Shigella flexneri in vivo.

Conclusions:

  • The type VI secretion system (T6SS) provides Shigella sonnei with a significant competitive advantage in the gut microbiome.
  • The T6SS-mediated advantage likely explains the increasing global prevalence of Shigella sonnei over Shigella flexneri.
Keywords:
S. sonneiType VI Secretionbacterial competitionvirulence and colonization

More Related Videos

Author Spotlight: Advancements in Understanding and Combatting Shigella Infections04:56

Author Spotlight: Advancements in Understanding and Combatting Shigella Infections

Published on: February 9, 2024

1.6K
Quantification of Interbacterial Competition using Single-Cell Fluorescence Imaging07:34

Quantification of Interbacterial Competition using Single-Cell Fluorescence Imaging

Published on: September 2, 2021

3.9K

Related Concept Videos

Gram-negative Bacterial Protein Secretion Systems01:17

Gram-negative Bacterial Protein Secretion Systems

Gram-negative bacteria utilize sophisticated protein secretion systems to transport proteins across their double-membrane envelope into the extracellular environment or host cells. Based on their mechanism of action, these systems are classified into one-step and two-step pathways.One-Step Secretion Systems (Types I, III, IV, and VI)One-step secretion systems bypass the periplasm entirely, forming a continuous channel that spans both the inner and outer membranes:Type I Secretion System (T1SS):...
1.2K
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...
420
Bacterial Translocation and Protein Secretion01:26

Bacterial Translocation and Protein Secretion

Bacterial protein secretion involves translocation systems to ensure proteins reach their designated locations, including the plasma membrane, periplasm, outer membrane, or the external environment. These translocation systems are vital for bacterial physiology, supporting processes like membrane assembly, enzymatic activity in the periplasm, and interactions with the external environment. The division of labor between Sec and Tat pathways ensures efficiency in handling proteins with diverse...
850
Transduction01:16

Transduction

Among the three main modes of HGT—transformation, conjugation, and transduction—transduction is unique in that it is mediated by bacteriophages, or bacterial viruses.Transduction occurs in two ways. Generalized transduction occurs during the lytic cycle of a bacteriophage infection. In this process, bacteriophages infect bacterial cells, replicate within them, and ultimately cause cell lysis, releasing newly assembled virions. Occasionally, random fragments of the bacterial genome...
2.1K