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XF-73, a novel antistaphylococcal membrane-active agent with rapid bactericidal activity
Nicola Ooi1, Keith Miller, Joanne Hobbs
1Antimicrobial Research Centre and Institute of Molecular and Cellular Biology, University of Leeds, Leeds, UK.
The Journal of Antimicrobial Chemotherapy
|August 20, 2009
Summary
XF-73 rapidly kills Staphylococcus aureus by disrupting its cell membrane, which halts essential processes like DNA, RNA, and protein synthesis. This novel porphyrin antibacterial agent shows potent membrane-perturbing activity.
Area of Science:
- Microbiology
- Pharmacology
- Bacterial Pathogenesis
Background:
- XF-73 is a novel porphyrin antibacterial agent.
- It is known to inhibit Gram-positive bacteria, including Staphylococcus aureus.
- The mechanism of action for XF-73 was previously unknown.
Purpose of the Study:
- To investigate the antibacterial mechanism of XF-73.
- To examine the basis of XF-73's activity against Staphylococcus aureus.
Main Methods:
- Investigated effects on S. aureus SH1000 growth and survival using viable counts and absorbance.
- Assessed inhibition of macromolecular synthesis via radiolabelling.
- Examined membrane integrity using BacLight assay and measuring K+/ATP leakage.
- Studied XF-73's effect on a staphylococcal coupled transcription-translation system.
Main Results:
- XF-73 demonstrated rapid bactericidal activity against S. aureus, with faster killing kinetics than comparators.
- Complete inhibition of DNA, RNA, and protein synthesis occurred within 10 minutes of exposure.
- XF-73 induced membrane damage, evidenced by positive BacLight assay results and significant K+/ATP leakage.
- No effect on in vitro transcription and translation was observed, and bacterial lysis was not promoted.
Conclusions:
- XF-73 possesses rapid membrane-perturbing activity.
- This membrane disruption is the likely cause of macromolecular synthesis inhibition.
- The observed effects lead to the death of staphylococci exposed to XF-73.
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