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Published on: April 18, 2019

Combined effect of eravacycline and omadacycline with other antimicrobial agents against Acinetobacter Baumannii

Özlem Erkoç Güleryüz1, Gülhan Vardar Ünlü2

  • 1Kırşehir Public Health Laboratory, Medical Microbiology Laboratory, Kırşehir, Türkiye. ozlemerkoc2016@gmail.com.

The Journal of Antibiotics
|May 27, 2026
PubMed

Insights

Novel antibiotics eravacycline and omadacycline show strong in vitro activity against multidrug-resistant Acinetobacter baumannii. Combinations with existing drugs like ceftazidime, meropenem, and colistin frequently demonstrated synergistic effects, offering hope for new treatment strategies.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Pharmacology

Background:

  • Multidrug-resistant Acinetobacter baumannii poses a significant global health threat.
  • Limited treatment options necessitate the development of novel therapeutic strategies.
  • Combination therapies are crucial for overcoming antimicrobial resistance.

Purpose of the Study:

  • To evaluate the in vitro antibacterial activity of eravacycline and omadacycline against clinical isolates of Acinetobacter baumannii.
  • To investigate the synergistic interactions of eravacycline and omadacycline with conventional antimicrobial agents.
  • To assess the potential of these novel tetracycline derivatives in combating resistant A. baumannii.

Main Methods:

  • Broth microdilution method to determine minimum inhibitory concentrations (MICs) of various antibiotics against 50 clinical A. baumannii isolates.
  • Checkerboard assay to evaluate synergistic interactions between eravacycline or omadacycline and other antibiotics in 10 meropenem-resistant isolates.
  • Testing included eravacycline, omadacycline, ceftazidime, meropenem, tobramycin, ciprofloxacin, and colistin.

Main Results:

  • Eravacycline and omadacycline exhibited low MIC values against the tested A. baumannii isolates, indicating potent intrinsic activity.
  • Frequent synergistic interactions were observed, particularly when eravacycline or omadacycline were combined with ceftazidime, meropenem, and colistin.
  • Both novel agents demonstrated promising in vitro efficacy as monotherapies and in combination regimens.

Conclusions:

  • Eravacycline and omadacycline are promising agents for treating multidrug-resistant Acinetobacter baumannii infections.
  • Combination therapies involving these novel tetracyclines may enhance efficacy against resistant strains.
  • Further clinical studies are warranted to explore their therapeutic potential in patients.

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