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Updated: Jun 15, 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

Genetic basis of multidrug resistance in Acinetobacter clinical isolates in Taiwan

Yu-Chi Lin1, Ko-Chiang Hsia, Yee-Chun Chen

  • 1Research and Diagnostic Center, Centers for Disease Control, Taipei, Taiwan.

Antimicrobial Agents and Chemotherapy
|March 3, 2010
PubMed

Insights

Multidrug-resistant Acinetobacter species pose a public health threat. This study identified key resistance genes, including gyrA mutations and ISAba1-bla elements, crucial for understanding and combating antibiotic resistance in Acinetobacter baumannii.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Public Health

Background:

  • Multidrug-resistant (MDR) Acinetobacter spp. are a significant global health concern.
  • Understanding the genetic basis of antibiotic resistance in these pathogens is critical for effective treatment strategies.

Purpose of the Study:

  • To investigate the genetic mechanisms conferring resistance to fluoroquinolones, aminoglycosides, cephalosporins, and carbapenems in clinical Acinetobacter isolates.
  • To elucidate the role of specific genes and mobile genetic elements in multidrug resistance.

Main Methods:

  • Analysis of 75 clinical Acinetobacter isolates from Taiwan.
  • Testing for gyrA mutations, integrons, bla(AmpC), and carbapenem resistance genes.
  • Experimental transformation to assess the function of ISAba1-bla elements.

Main Results:

  • Fluoroquinolone resistance was linked to the Ser83Leu mutation in GyrA.
  • Integrons correlated with resistance to gentamicin and tobramycin, but not amikacin.
  • ISAba1 element upstream of bla(AmpC) was associated with cephalosporin resistance.
  • ISAba1-bla(OXA-23) and ISAba1-bla(OXA-66) conferred resistance to carbapenems and piperacillin-tazobactam.
  • The ISAba1 element acts as a strong promoter for resistance gene expression.

Conclusions:

  • Specific genetic mutations and the ISAba1 element play key roles in the multidrug resistance of Acinetobacter spp.
  • The findings highlight the importance of continuous surveillance and understanding resistance mechanisms for developing new therapies and preventing spread.

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