# Surface dependent inhibition of Mycobacterium abscessus by Pseudomonas aeruginosa

> **NIH NIH R21** · OHIO STATE UNIVERSITY · 2024 · $236,250

## Abstract

Project Abstract
Treatment of biofilm-associated infections, such as those caused by Pseudomonas aeruginosa and non-
tuberculous mycobacteria (NTM), can be extremely challenging, especially when these infectious agents co-
infect the lungs of people with cystic fibrosis (CF) or other diseases. This application seeks to understand
community interactions between P. aeruginosa and the antibiotic resistant NTM Mycobacterium abscessus. P.
aeruginosa and M. abscessus are both found in the same environmental reservoirs and are co-isolated from
individuals with CF and surgical site/soft tissue infections. Indeed, studies demonstrate that M. abscessus
positive CF individuals are more likely to be infected with P. aeruginosa. Despite this, there is limited
understanding of the interaction between these two important opportunistic pathogens. We recently
investigated M. abscessus and P. aeruginosa interactions and reported several novel observations. P.
aeruginosa potently antagonizes both rough and smooth M. abscessus variants, yet only when co-cultured in
dual-species biofilms; antagonism was not observed in planktonic co-culture. Multiple P. aeruginosa strains
exhibited antagonism, and P. aeruginosa-mediated antagonism was observed with another NTM strain,
Mycobacterium smegmatis. Surprisingly, antagonism did not require known P. aeruginosa contact-dependent
or -independent killing, motility, or oxygen/iron sequestration mechanisms. Thus, we hypothesize that inter-
bacterial antagonism of M. abscessus by P. aeruginosa in dual-species biofilms is mediated by a novel
antibacterial strategy. Aim 1 will utilize several complementary strategies to identify the mechanism of
interbacterial antagonism. Aim 2 seeks to investigate M. abscessus and P. aeruginosa interactions under
conditions that closely mimic those found in the host. The growing prevalence of M. abscessus infections and
their recalcitrance to both host clearance and antibiotics highlight an urgent need to find new strategies to
successfully treat these persistent infections. Successful completion of this proposal will advance our
understanding of the novel P. aeruginosa antagonistic mechanism towards M. abscessus biofilms and provide
novel biofilm targets that could be leveraged to augment antimicrobial efficacy in people with inflammatory and
muco-obstructive lung disorders such as CF, chronic obstructive pulmonary disease (COPD), and non-CF
bronchiectasis as well as with other NTM lung infections such as Mycobacterium avium.

## Key facts

- **NIH application ID:** 10987723
- **Project number:** 1R21AI181224-01A1
- **Recipient organization:** OHIO STATE UNIVERSITY
- **Principal Investigator:** Luanne Hall-Stoodley
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $236,250
- **Award type:** 1
- **Project period:** 2024-05-21 → 2026-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10987723

## Citation

> US National Institutes of Health, RePORTER application 10987723, Surface dependent inhibition of Mycobacterium abscessus by Pseudomonas aeruginosa (1R21AI181224-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10987723. Licensed CC0.

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