Related Experiment Video
Updated: Sep 18, 2026

Measuring Bacterial Load and Immune Responses in Mice Infected with Listeria monocytogenes
Published on: August 9, 2011
Susceptibility of Listeria monocytogenes to antimicrobial peptides
Emilia López-Solanilla1, Bruno González-Zorn, Susana Novella
1Departamento de Biotecnología, ETS de Ingenieros Agrónomos, Universidad Politécnica, 28040, Madrid, Spain.
Abstract:
We assessed the susceptibility of several pathogenic and non-pathogenic Listeria species to antimicrobial peptides of animal and plant origin. Human defensins and thionins were highly inhibitory, whereas protamine, snakin and magainin showed an intermediate effect. A temperature dependence in the activity of potato defensin was observed for Listeria monocytogenes and Listeria ivanovii. PrfA* L. monocytogenes mutants, that overexpress constitutively PrfA-dependent genes, were sensitive to the peptide independently of the temperature whereas isogenic PrfA(-) derivatives were constitutively resistant. These data indicate that the thermoregulated transcription factor PrfA controls the expression of bacterial products that influence the susceptibility or resistance to some antimicrobial peptides.
Related Concept Videos
Antimicrobial Proteins
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...
Clinical Significance of Antibiotic Resistance
Defense Against Bacterial Pathogens
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
Bacterial Cell Wall
Inhibitors of Gram-positive Cell Wall Synthesis
Biological Methods for Microbial Control

