Bacterial changes that make colistin and other polymyxins less effective

Modifications of Lipid A with Phospho-Ethanolamine Impacting Polymyxin Resistance

NIH-funded research University of Colorado · NIH-11233298

Researchers are working on drugs that block a bacterial enzyme so last-resort antibiotics like colistin can work again for people with resistant Acinetobacter infections.

Quick facts

Grant typeR21 grant
Study typeNIH-funded research
Funding institutionUniversity of Colorado NIH-funded
Lab location1 site (Boulder, UNITED STATES)
Project IDNIH-11233298 on NIH RePORTER

What this research studies

Some bacteria such as Acinetobacter baumannii add a small chemical to their outer surface that helps them survive antibiotics like colistin. Scientists at the University of Colorado will study how that chemical (phosphoethanolamine) is attached to lipid A and try to make compounds that block the enzyme that does this. The work is mainly laboratory-based using bacterial cultures and biochemical tests, and may include models to see if combining the blocker with colistin restores killing of resistant strains. The goal is to identify a drug-like molecule that could later move toward testing in patients.

Who could benefit from this research

Good fit: Patients with infections caused by carbapenem-resistant or colistin-resistant Acinetobacter baumannii would be the most relevant group to benefit.

Not a fit: People with infections caused by other types of bacteria or whose infections are already treatable with standard antibiotics are unlikely to see direct benefit.

Why it matters

Potential benefit: If successful, this could restore the effectiveness of colistin against deadly multidrug-resistant infections like carbapenem-resistant Acinetobacter, potentially reducing deaths from these infections.

How similar studies have performed: Laboratory studies have shown that blocking lipid A modifications can restore colistin sensitivity in bacteria, but no inhibitor from this approach has yet become an approved clinical treatment.

Where this research is happening

Boulder, UNITED STATES

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.