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Synthesis and antibiotic activity of novel acylated phloroglucinol compounds against methicillin-resistant Staphylococcus aureus

Abstract

The rise in antibiotic resistance among pathogenic microorganisms has created an imbalance in the drugs available for treatment, in part due to the slow development of new antibiotics. Cystic fibrosis (CF) patients are highly susceptible to antibiotic-resistant pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). Phloroglucinols and related polyketide natural products have demonstrated antimicrobial activity against a number of Gram-positive bacteria including S. aureus. In this study, we investigated a series of acylated phloroglucinol derivatives to determine their potential as lead compounds for the design of novel therapeutics. To assess the activity of these compounds, we determined the minimum inhibitory and bactericidal concentration (MIC and MBC, respectively), the minimum biofilm inhibitory and biofilm eradication concentration (MBIC and MBEC, respectively), and evaluated hemolytic activity, as well as their interaction with clinically relevant antibiotics. Of the 12 compounds tested against MRSA and methicillin-susceptible strains, four showed MIC values ranging from 0.125 to 8 µg ml−1 and all of them were bactericidal. However, none of the compounds were able to eradicate biofilms at the concentrations tested. Three of the four did not display hemolytic activity under the conditions tested. Further studies on the interactions of these compounds with clinically relevant antibiotics showed that phlorodipropanophenone displayed synergistic activity when paired with doxycycline. Our results suggest that these acylated phloroglucinols have potential for being further investigated as antibacterial leads.

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References

  1. Munita JM, Shelburne S, Greenberg DE, Arias CA. The growing threat of antimicrobial resistance. Tex Med. 2017;113:48–52.

    PubMed  Google Scholar 

  2. Public Health Agency of Canada. Canadian antimicrobial resistance surveillance system 2017 Report. 2017.

  3. Chambers HF, DeLeo FR. Waves of resistance: Staphylococcus aureus in the antibiotic era. Nat Rev Microbiol. 2009;7:629–41.

    CAS  Article  Google Scholar 

  4. Stryjewski ME, Corey GR. Methicillin-resistant Staphylococcus aureus: an evolving pathogen. Clin Infect Dis. 2014;58:S10–S19.

    CAS  Article  Google Scholar 

  5. Miller LG, Kaplan SL. Staphylococcus aureus: a community pathogen. Infect Dis Clin North Am. 2009;23:35–52.

    Article  Google Scholar 

  6. Akil N, Muhlebach MS. Biology and management of methicillin resistant Staphylococcus aureus in cystic fibrosis. Pediatr Pulmonol. 2018. https://doi.org/10.1002/ppul.24139

    Article  Google Scholar 

  7. Gangell C, et al. Inflammatory responses to individual microorganisms in the lungs of children with cystic fibrosis. Clin Infect Dis. 2011;53:425–32.

    Article  Google Scholar 

  8. Pena Amaya P, et al. Molecular epidemiology of methicillin-resistant Staphylococcus aureus in cystic fibrosis patients from Argentina. Microb Drug Resist. 2017. https://doi.org/10.1089/mdr.2017.0162

    CAS  Article  Google Scholar 

  9. Muhlebach MS. Methicillin-resistant Staphylococcus aureus in cystic fibrosis: how should it be managed? Curr Opin Pulm Med. 2017;23:544–50.

    Article  Google Scholar 

  10. Harvey AL, Edrada-Ebel R, Quinn RJ. The re-emergence of natural products for drug discovery in the genomics era. Nat Rev Drug Discov. 2015;14:111–29.

    CAS  Article  Google Scholar 

  11. Heihachiro T, Ushio S, Shoji S. Biosynthesis of natural products.VI) Biosynthesis of usnic acid in lichen’s (1). A general scheme of biosynthesis of usnic acid. Chem Pharma. 1969;17:2054–60.

    Article  Google Scholar 

  12. Sarkar R, Mittal N, Sorensen J, Sen T. A comparison of the bioactivity of usnic acid versus methylphloracetophenone. Nat Prod Commun. 2018;13:1673–6.

    Google Scholar 

  13. Pena Amaya P, et al. Molecular epidemiology of methicillin-resistant Staphylococcus aureus in cystic fibrosis patients from Argentina. Microb Drug Resist. 2018;24:613–20.

    CAS  Article  Google Scholar 

  14. Pankey GA, Sabath LD. Clinical relevance of bacteriostatic versus bactericidal mechanisms of action in the treatment of Gram-positive bacterial infections. Clin Infect Dis. 2004;38:864–70.

    CAS  Article  Google Scholar 

  15. Brochado AR, et al. Species-specific activity of antibacterial drug combinations. Nature. 2018;559:259–63.

    CAS  Article  Google Scholar 

  16. Sahuquillo Arce JM. In vitro activity of linezolid in combination with doxycycline, fosfomycin, levofloxacin, rifampicin and vancomycin against methicillin-susceptible Staphylococcus aureus. Rev Esp Quimioterap. 2006;19:252–7.

    CAS  Google Scholar 

  17. Clinical and Laboratory Standards Institute CLSI. Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically; approved standard. 9th ed. CLSI; Wayne, USA, 2012.

  18. Zhang E, et al. Synthesis and bioactivities study of new antibacterial peptide mimics: the dialkyl cationic amphiphiles. Eur J Med Chem. 2018;143:1489–509.

    CAS  Article  Google Scholar 

  19. Evie IM, Dickson AJ, Elvin M. Metabolite profiling of mammalian cell culture processes to evaluate cellular viability. In: Gilbert DF, Friedrich O, editors. Cell viability assays: methods and protocols. New York: Springer; 2017. p. 137–52.

    Google Scholar 

  20. Garcia Lynne S. Clinical microbiology procedures handbook, vols. 1–3. 3rd ed. ASM Press, Washington, DC, 2016.

  21. van Belkum A, et al. Meropenem/colistin synergy testing for multidrug-resistant Acinetobacter baumannii strains by a two-dimensional gradient technique applicable in routine microbiology. J Antimicrob Chemother. 2015;70:167–72.

    Article  Google Scholar 

  22. Hogan AM, et al. Competitive fitness of essential gene knockdowns reveals a broad-spectrum antibacterial inhibitor of the cell division protein FtsZ. Antimicrob Agents Chemother. 2018;62:e01231–18.

    CAS  Article  Google Scholar 

  23. Selin C, et al. A pipeline for screening small molecules with growth inhibitory activity against Burkholderia cenocepacia. PLoS One. 2015;10:e0128587.

    Article  Google Scholar 

  24. Sperandio D, et al. Cell-associated hemolysis activity in the clinical strain of Pseudomonas fluorescens MFN1032. BMC Microbiol. 2010;10:124.

    Article  Google Scholar 

Download references

Acknowledgements

This study was supported by a Discovery Grant from the Natural Sciences and Engineering Research Council (NSERC) to John Sorensen and a Mid-Career Award from Research Manitoba to Silvia Cardona. The assistance of Harmanpreet Tatla in the initial synthesis of compounds 912 is also gratefully acknowledged.

Author contributions

NM designed and performed synthesis of the compounds, HHT tested the activity of the compounds. NM and HHT interpreted the data and wrote the manuscript. AMH supervised and edited the final version of the manuscript. STC and JLS conceived the research approach, contributed to writing and edited the final version of the manuscript.

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Correspondence to John L. Sorensen.

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Mittal, N., Tesfu, H.H., Hogan, A.M. et al. Synthesis and antibiotic activity of novel acylated phloroglucinol compounds against methicillin-resistant Staphylococcus aureus. J Antibiot 72, 253–259 (2019). https://doi.org/10.1038/s41429-019-0153-4

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