These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Dual antibacterial mechanisms of nisin Z against Gram-positive and Gram-negative bacteria.
    Author: Kuwano K, Tanaka N, Shimizu T, Nagatoshi K, Nou S, Sonomoto K.
    Journal: Int J Antimicrob Agents; 2005 Nov; 26(5):396-402. PubMed ID: 16226432.
    Abstract:
    Nisin, an amphipathic antibiotic peptide, is produced by a number of strains of Lactococcus lactis subsp. lactis. It has been employed as a food preservative as it has a high antibacterial activity with a relatively low toxicity for humans. Nisin is known to exert a high antibacterial activity against Gram-positive but not Gram-negative bacteria. However, purified nisin Z was found to show an antibacterial activity both against Gram-positive and Gram-negative bacteria. To clarify the mechanisms of activity, nisin Z and purified nisin Z were tested for their antibacterial activities in a high-salt environment. The activity of nisin Z against Staphylococcus aureus was stable even in the presence of NaCl at 100 mM, showing ca. 2log colony-forming unit (CFU) reduction. In contrast, the activity of nisin Z against Escherichia coli was highly sensitive to the same concentration of NaCl, and CFU reduction was not observed. Furthermore, purified nisin Z caused the permeabilisation both of S. aureus and E. coli cytoplasmic membranes. The permeabilisation of E. coli but not S. aureus cytoplasmic membranes was remarkably reduced in a high-salt environment. Moreover, vancomycin inhibited the nisin Z-induced permeabilisation of the S. aureus cytoplasmic membrane. These results suggest that nisin Z utilises two distinct mechanisms of antibacterial activity: a high-salt-sensitive mechanism for E. coli and a high-salt-insensitive mechanism for S. aureus.
    [Abstract] [Full Text] [Related] [New Search]