Antimicrobial potential of myristic acid against Listeria monocytogenes in milk

J Antibiot (Tokyo). 2019 May;72(5):298-305. doi: 10.1038/s41429-019-0152-5. Epub 2019 Feb 21.

Abstract

Listeria monocytogenes (L. monocytogenes), an important food-borne pathogenic microorganism, has resistance immune function to many commonly used drugs. Myristic acid is a traditional Chinese herbal medicine, but it has been rarely used as a food additive, limiting the development of natural food preservatives. In this study, the antibacterial activity and mechanism of myristic acid against L. monocytogenes were studied. The minimum inhibitory concentration (MIC) of myristic acid against 13 L. monocytogenes strains ranged from 64 to 256 μg ml-1. The time-kill assay demonstrated that when myristic acid was added to dairy products, flow cytometry confirmed that myristic acid influenced cell death and inhibited the growth of L. monocytogenes. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), and NPN uptake studies illustrated that myristic acid changed the bacterial morphology and membrane structure of L. monocytogenes, which led to rapid cell death. Myristic acid could bind to DNA and lead to changes in DNA conformation and structure, as identified by fluorescence spectroscopy. Our studies provide additional evidence to support myristic acid being used as a natural antibacterial agent and also further fundamental understanding of the modes of antibacterial action.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology*
  • Cell Membrane / drug effects
  • Disease Transmission, Infectious
  • Flow Cytometry
  • Listeria monocytogenes / cytology
  • Listeria monocytogenes / drug effects*
  • Listeria monocytogenes / growth & development
  • Listeria monocytogenes / physiology
  • Microbial Sensitivity Tests
  • Microbial Viability / drug effects
  • Microscopy, Electron, Scanning
  • Microscopy, Electron, Transmission
  • Milk / microbiology*
  • Myristic Acid / pharmacology*
  • Nucleic Acid Conformation / drug effects
  • Spectrometry, Fluorescence

Substances

  • Anti-Bacterial Agents
  • Myristic Acid