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Updated: Oct 18, 2025
Visualization of Bacterial Resistance using Fluorescent Antibiotic Probes
Published on: March 2, 2020
Harnessing Fluorescent Moenomycin A Antibiotics for Bacterial Cell Wall Imaging Studies
Pei-Yu Hsieh1, Fan-Chun Meng2, Chih-Wei Guo2
1Institute of Biological Chemistry, Academia Sinica, No. 128, Academia Road Sec. 2, Taipei, 115, Taiwan.
Abstract:
The imaging of peptidoglycan (PGN) dynamics in living bacteria facilitates the understanding of PGN biosynthesis and wall-targeting antibiotics. The main tools for imaging bacterial PGN are fluorescent probes, such as the well-known PGN metabolic labeling probes. However, fluorescent small-molecule probes for labeling key PGN-synthesizing enzymes, especially for transglycosylases (TGases), remain to be explored. In this work, the first imaging probe for labeling TGase in bacterial cell wall studies is reported. We synthesized various fluorescent MoeA-based molecules by derivatizing the natural antibiotic moenomycin A (MoeA), and used them to label TGases in living bacteria, monitor bacterial growth and division cycles by time-lapse imaging, and study cell wall growth in the mecA-carrying methicillin-resistant Staphylococcus aureus (MRSA) strains when the β-lactam-based probes were unsuitable.
Insights
Researchers developed the first fluorescent probes to visualize transglycosylases (TGases) in bacteria. These probes aid in studying bacterial cell wall synthesis and antibiotic mechanisms, especially in resistant strains.
Area of Science:
- Microbiology
- Biochemistry
- Chemical Biology
Background:
- Imaging peptidoglycan (PGN) dynamics is crucial for understanding bacterial cell wall synthesis and antibiotic action.
- Existing fluorescent probes primarily target PGN metabolism, leaving key enzymes like transglycosylases (TGases) unvisualized.
- There is a need for novel probes to specifically label and track TGase activity in living bacteria.
Purpose of the Study:
- To develop and characterize the first fluorescent small-molecule probes for labeling bacterial TGases.
- To utilize these probes for monitoring bacterial growth, division, and cell wall dynamics.
- To investigate TGase activity in methicillin-resistant Staphylococcus aureus (MRSA) where conventional probes are ineffective.
Main Methods:
- Synthesis of fluorescent MoeA-based molecules derived from moenomycin A.
- Labeling of TGases in living bacterial cells using the synthesized probes.
- Time-lapse imaging to monitor bacterial growth and division cycles.
- Application of probes in studying cell wall growth in MRSA strains.
Main Results:
- Successfully synthesized novel fluorescent probes targeting bacterial TGases.
- Demonstrated the ability of probes to label TGases in living bacteria.
- Visualized bacterial growth and division cycles using time-lapse imaging with the probes.
- Successfully studied cell wall growth in MRSA, overcoming limitations of β-lactam probes.
Conclusions:
- The developed MoeA-based probes represent the first tools for imaging TGase activity in bacteria.
- These probes offer a new method for studying bacterial cell wall biosynthesis and antibiotic mechanisms.
- The probes are valuable for investigating bacterial physiology, particularly in challenging strains like MRSA.
