
==== Front
bioRxiv
BIORXIV
bioRxiv
2692-8205
Cold Spring Harbor Laboratory

10.1101/2024.08.23.609441
preprint
1
Article
Efflux pumps and membrane permeability contribute to intrinsic antibiotic resistance in Mycobacterium abscessus
McGowen Kerry http://orcid.org/0000-0002-8451-4070

Funck Tobias
Wang Xin http://orcid.org/0000-0002-6930-3347

Zinga Samuel
Wolf Ian D.
Akusobi Chidiebere C.
Denkinger Claudia M.
Rubin Eric J.
Sullivan Mark R. http://orcid.org/0000-0001-5765-0459

24 8 2024
2024.08.23.609441https://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License, which allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator. The license allows for commercial use.
http://biorxiv.org/lookup/doi/10.1101/2024.08.23.609441
nihpp-2024.08.23.609441.pdf
Abstract

Mycobacterium abscessus is a pulmonary pathogen that exhibits intrinsic resistance to antibiotics, but the factors driving this resistance are incompletely understood. Insufficient intracellular drug accumulation could explain broad-spectrum resistance, but whether antibiotics fail to accumulate in M. abscessus and the mechanisms required for drug exclusion remain poorly understood. We measured antibiotic accumulation in M. abscessus using mass spectrometry and found a wide range of drug accumulation across clinically relevant antibiotics. Of these compounds, linezolid accumulates the least, suggesting that inadequate uptake impacts its efficacy. We utilized transposon mutagenesis screening to identify genes that cause linezolid resistance and found multiple transporters that promote membrane permeability or efflux, including an uncharacterized, M. abscessus -specific protein that effluxes linezolid and several chemically related antibiotics. This demonstrates that membrane permeability and drug efflux are critical mechanisms of antibiotic resistance in M. abscessus and suggests that targeting membrane transporters could potentiate the efficacy of certain antibiotics.
==== Body
pmc
