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Updated: Jan 10, 2026
Author Spotlight: Scalable Drug Screening Protocol for Efficient Discovery of M. abscessus Treatments
Published on: October 25, 2024
A bioluminescence-based chemical screen identifies a bactericidal naphthalene scaffold targeting MmpL3 in
Samsher Singh1, Ria Sorayah1, Yushu Chen2
1Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 636921, Singapore.
Abstract:
Mycobacterium abscessus pulmonary disease (Mabs-PD) presents a significant and growing global health threat, particularly in individuals with underlying lung conditions like cystic fibrosis and chronic obstructive pulmonary disease. A key challenge in treating Mabs-PD is the lack of bactericidal antibiotics effective at therapeutically relevant concentrations, underscoring an urgent need for drug discovery. Targeting cell-wall synthesis is a promising approach, as evidenced by the success of broad-spectrum β-lactam antibiotics and the frontline antituberculosis drug isoniazid. However, these agents exhibit limited efficacy against Mabs, often requiring concentrations unachievable in lung tissues. Here, we used a bioluminescence-based whole-cell assay optimized to identify drugs targeting both cell-wall synthesis and the oxidative phosphorylation pathway. Screening a small drug library against Mabs revealed multiple hits, including β-lactam antibiotics, validating the effectiveness of this approach to identify cell wall-targeting agents. Among these, we identified a chemically tractable naphthalene scaffold with potent bactericidal activity. The optimized derivative GM47-1 targets MmpL3, disrupting cell wall integrity, inducing ATP leakage into the extracellular milieu, and uncoupling respiration, predominantly through the cytochrome bcc:aa 3 branch. Further chemical optimization resulted in a new derivative exhibiting a nanomolar minimum inhibitory concentration, with potent activity against intracellular Mabs and in a zebrafish model of infection. This study offers a promising scaffold for future therapeutic development and highlights the utility of this approach as a rapid assay platform for identifying bactericidal compounds against Mabs.
Insights
Researchers discovered a new naphthalene-based drug effective against Mycobacterium abscessus pulmonary disease (Mabs-PD). This compound targets cell wall synthesis and respiration, showing potent bactericidal activity in preclinical models.
Area of Science:
- Microbiology
- Drug Discovery
- Antimicrobial Resistance
Background:
- Mycobacterium abscessus pulmonary disease (Mabs-PD) is a growing global health concern, especially for patients with cystic fibrosis or COPD.
- Current treatments for Mabs-PD are limited by the lack of bactericidal antibiotics effective at therapeutic concentrations.
- Targeting bacterial cell-wall synthesis is a promising strategy for developing new antimicrobials.
Purpose of the Study:
- To develop and validate a bioluminescence-based assay for identifying bactericidal drugs against Mycobacterium abscessus.
- To discover novel drug scaffolds targeting cell-wall synthesis and/or oxidative phosphorylation in M. abscessus.
- To optimize lead compounds for potent activity against M. abscessus infections.
Main Methods:
- Screening of a drug library using a novel bioluminescence-based whole-cell assay targeting cell-wall synthesis and oxidative phosphorylation.
- Chemical optimization of identified hit compounds, focusing on a naphthalene scaffold.
- Evaluation of lead compound efficacy in vitro (minimum inhibitory concentration, intracellular activity) and in vivo (zebrafish infection model).
Main Results:
- The assay successfully identified known cell-wall targeting agents, validating its effectiveness.
- A naphthalene scaffold was identified with potent bactericidal activity against M. abscessus.
- The optimized derivative GM47-1 targets MmpL3, disrupts cell wall integrity, and affects respiration.
- Further optimization yielded a derivative with nanomolar MIC, potent intracellular activity, and efficacy in a zebrafish model.
Conclusions:
- A novel naphthalene scaffold provides a promising starting point for developing new therapeutics against Mabs-PD.
- The developed bioluminescence assay is a valuable platform for rapid identification of bactericidal compounds against M. abscessus.
- Targeting MmpL3 and respiration represents a viable strategy for combating M. abscessus infections.
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