Related Experiment Video

Updated: Nov 26, 2025

Author Spotlight: Advancing Antibiotic Resistance Research Using an Efflux-Deficient Bacterial Strain and a Single-Copy Gene Expression System
05:06

Author Spotlight: Advancing Antibiotic Resistance Research Using an Efflux-Deficient Bacterial Strain and a Single-Copy Gene Expression System

Published on: January 5, 2024

888

Virulence role of the outer membrane protein CarO in carbapenem-resistant Acinetobacter baumannii

Gema Labrador-Herrera1,2, Antonio J Pérez-Pulido3, Rocío Álvarez-Marín1,2

  • 1Clinical Unit of Infectious Diseases, Microbiology, and Preventive Medicine, University Hospital Virgen del Rocío , Seville, Spain.

Virulence
|December 10, 2020
PubMed

Insights

Carbapenem-resistant Acinetobacter baumannii (CRAB) infections require new treatments. The CarO protein, previously unnoticed, may be a target for anti-virulence drugs against CRAB.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Genomics

Background:

  • Novel therapies are crucial for treating carbapenem-resistant Acinetobacter baumannii (CRAB) infections.
  • Anti-virulence drugs offer a promising alternative to traditional antibiotics, but target identification remains limited.

Purpose of the Study:

  • To identify potential virulence factors of CRAB by comparing clinical isolates from patients with different outcomes.
  • To investigate the role of the CarO protein in A. baumannii virulence.

Main Methods:

  • Whole-genome sequencing of CRAB clinical isolates from patients with ventilator-associated pneumonia.
  • Proteomic and immunoblot analyses to corroborate gene findings.
  • In vitro (cell adhesion and invasion assays) and in vivo virulence studies of A. baumannii mutants.

Main Results:

  • The carO gene was found to be interrupted in CRAB isolates from surviving patients, but intact in isolates from non-surviving patients.
  • Isogenic ΔcarO mutants and CRAB isolates with truncated CarO exhibited reduced adherence to and invasion of A549 cells.
  • A. baumannii lacking functional CarO showed decreased in vivo virulence.

Conclusions:

  • The outer membrane protein CarO plays a previously unrecognized role in A. baumannii virulence.
  • CarO is a potential therapeutic target for developing novel anti-virulence strategies against CRAB infections.
Keywords:
Acinetobacter baumanniiCarObloodstream infectionscarbapenem-resistancevirulence factorwhole-genome sequencing

More Related Videos

Separation of the Cell Envelope for Gram-negative Bacteria into Inner and Outer Membrane Fractions with Technical Adjustments for Acinetobacter baumannii10:24

Separation of the Cell Envelope for Gram-negative Bacteria into Inner and Outer Membrane Fractions with Technical Adjustments for Acinetobacter baumannii

Published on: April 10, 2020

14.0K
A Non-Coding Small RNA MicC Contributes to Virulence in Outer Membrane Proteins in Salmonella Enteritidis06:30

A Non-Coding Small RNA MicC Contributes to Virulence in Outer Membrane Proteins in Salmonella Enteritidis

Published on: January 27, 2021

1.9K

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,...
273
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):...
410
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...
271
Membrane Carbohydrates01:30

Membrane Carbohydrates

The plasma membrane is a dynamic barrier composed of lipids, proteins, and carbohydrates. It is the epicenter of many cellular processes required for cell growth and survival. Carbohydrates have unique structural and chemical properties that help the plasma membrane to carry out its functions effectively.
Membrane carbohydrates do not have any hydrophobic region and are exclusively located on the cell's outer surface. The addition of sugar molecules or glycosylation of proteins happens in...
6.7K
Surface Membrane Barriers01:18

Surface Membrane Barriers

The skin and mucous membranes serve as the primary line of defense against pathogens by providing both physical and chemical protection. These barriers are essential in preventing the entry and establishment of microbes, thereby maintaining the integrity of the host.
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...
2.1K
Antimicrobial Proteins01:23

Antimicrobial Proteins

Antimicrobial proteins are important components of the immune system. They aid the body in combating pathogens by either killing them directly or hindering their replication processes. Four main types of antimicrobial substances are interferons, the complement system, iron-binding proteins, and antimicrobial proteins.
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...
12.4K