PROJECT SUMMARY
Methicillin-resistant Staphylococcus aureus (MRSA) continues to gain resistance to existing antibiotics, and the
lack of big pharma pipelines to develop new compounds that target superbugs means that serious attention is
needed within the academic research community. Although a limited number of compounds have been put forth
to address the MRSA resistance problem, there is still a critical need to develop novel compounds with improved
antibacterial activity. Synthetic unsaturated fatty acids (uFAs) are attractive candidates to become next-
generation antibacterial agents for treating MRSA infections because they appear to have multiple
mechanisms of action, making it more difficult for bacteria to develop resistance. In addition, synthetic
uFAs can directly kill multi-drug resistant bacteria at very low concentrations (i.e., at the micromolar and
nanomolar level). Recent experimental data suggest that the cytotoxic activity of either 2-hexadecynoic acid (2-
HDA, triple-bonded FA) or DAT-51(double-bonded FA) against MRSA is due to their ability to disrupt the cell
membrane, possibly by pore formation. The long-term goal of this project is to define the mechanisms that
explain the total antibacterial activity of uFAs and apply this knowledge to develop a next-generation of synthetic
uFAs with even better efficacy as antibacterial agents. Our central hypothesis is that uFAs such as 2-HDA or
DAT-51 can induce membrane disruption through direct pore formation. Two independent but related Specific
Aims proposed here will test our central hypothesis. In the first aim, we will determine if 2-HDA and/or DAT-
51 disrupt the cell membrane of S. aureus using flow cytometry, DNA/RNA leakage assays, and electron
microscopy. The second aim will define the inhibitory effects of 2-HDA or DAT-51 on S. aureus peptidoglycan
biosynthesis by using Western blot and standard colorimetric assays. The knowledge acquired from this project
will significantly impact the field because it will allow us to establish the chemical and biological foundations
required for the targeted design of the next generation of synthetic uFAs with improved antibacterial activity.
Therefore, the successful completion of this project is likely to lead to the development of new therapeutic options
to treat devastating MRSA infections.
