Low-cost anti-mycobacterial drug discovery using engineered E. coli

Area of Science:

• Synthetic biology
• Microbiology
• Drug discovery

Background:

• Whole-cell screening for Mycobacterium tuberculosis (Mtb) drug inhibitors is challenging due to slow growth and biocontainment needs.
• Developing novel antimicrobial agents requires innovative screening platforms.

Purpose of the Study:

• To present a synthetic biology framework for assaying Mtb drug targets in engineered E. coli.
• To identify novel inhibitors of Mtb essential targets using this platform.

Main Methods:

• Constructed Target Essential Surrogate E. coli (TESEC) strains by replacing an essential E. coli enzyme with an Mtb functional analog.
• Performed high-throughput screening of TESEC models for Mtb alanine racemase (Alr) activity.
• Validated identified inhibitors in whole-cell Mtb and conducted in vitro biochemical assays.

Main Results:

• Identified benazepril as a targeted inhibitor of Mtb alanine racemase (Alr) via TESEC screening.
• Validated benazepril's activity in whole-cell Mtb assays.
• Demonstrated the scalability of the TESEC framework for four additional Mtb targets.

Conclusions:

• The TESEC framework provides a scalable and efficient platform for Mtb drug discovery.
• Benazepril is a novel, noncompetitive inhibitor of Mtb alanine racemase.
• This approach overcomes limitations of traditional Mtb screening methods.