Related Experiment Video

Updated: Jul 16, 2026

Characterizing Multidrug Efflux Systems in Acinetobacter baumannii Using an Efflux-Deficient Bacterial Strain and a Single-Copy Gene Expression System
05:06

Characterizing Multidrug Efflux Systems in Acinetobacter baumannii Using an Efflux-Deficient Bacterial Strain and a Single-Copy Gene Expression System

Published on: January 5, 2024

Disruption of rcnB modulates colistin susceptibility in Acinetobacter baumannii AB5075

Yuying Zhang1, Jiabao Xing1,2, Hang Zhang1

  • 1Department of Pharmacology and Toxicology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China.

Virulence
|July 14, 2026
PubMed

Insights

The gene rcnB significantly impacts colistin resistance in Acinetobacter baumannii. Deleting rcnB increases susceptibility to colistin by affecting cell membrane integrity and stress defenses.

Area of Science:

  • Microbiology
  • Genetics
  • Molecular Biology

Background:

  • Acinetobacter baumannii is a multidrug-resistant pathogen causing difficult-to-treat infections.
  • Colistin is a last-resort antibiotic, but resistance is emerging rapidly.
  • Understanding resistance mechanisms is crucial for effective treatment.

Purpose of the Study:

  • To investigate the role of the rcnB gene in colistin susceptibility in Acinetobacter baumannii.
  • To elucidate the molecular mechanisms by which rcnB affects antibiotic resistance.

Main Methods:

  • Utilized CRISPR-Cas9 genome editing to create an rcnB deletion mutant (ΔrcnB) in A. baumannii AB5075.
  • Performed transcriptomic profiling to analyze global gene expression changes.
  • Assessed changes in membrane integrity, oxidative stress response, and efflux pump activity.

Main Results:

  • Loss of rcnB significantly enhanced colistin-mediated killing.
  • ΔrcnB mutant exhibited compromised membrane integrity and impaired oxidative stress defenses.
  • Transcriptomic analysis revealed rcnB deletion altered stress-response networks, including fatty acid biosynthesis and ROS detoxification pathways.

Conclusions:

  • rcnB plays a previously unrecognized role in modulating colistin susceptibility in A. baumannii.
  • Mechanistic insights into rcnB function provide potential targets for enhancing colistin efficacy against multidrug-resistant strains.
Keywords:
AB5075Acinetobacter baumanniiCRISPR-Cas9colistingene editingrcnB gene

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