Staphylococcus aureus Mutant Screen Reveals Interaction of the Human Antimicrobial Peptide Dermcidin with Membrane Phospholipids
- 1 October 2009
- journal article
- research article
- Published by American Society for Microbiology in Antimicrobial Agents and Chemotherapy
- Vol. 53 (10), 4200-4210
- https://doi.org/10.1128/aac.00428-09
Abstract
Antimicrobial peptides (AMPs) form an important part of the innate host defense. In contrast to most AMPs, human dermcidin has an anionic net charge. To investigate whether bacteria have developed specific mechanisms of resistance to dermcidin, we screened for mutants of the leading human pathogen, Staphylococcus aureus, with altered resistance to dermcidin. To that end, we constructed a plasmid for use in mariner-based transposon mutagenesis and developed a high-throughput cell viability screening method based on luminescence. In a large screen, we did not find mutants with strongly increased susceptibility to dermcidin, indicating that S. aureus has no specific mechanism of resistance to this AMP. Furthermore, we detected a mutation in a gene of unknown function that resulted in significantly increased resistance to dermcidin. The mutant strain had an altered membrane phospholipid pattern and showed decreased binding of dermcidin to the bacterial surface, indicating that dermcidin interacts with membrane phospholipids. The mode of this interaction was direct, as shown by assays of dermcidin binding to phospholipid preparations, and specific, as the resistance to other AMPs was not affected. Our findings indicate that dermcidin has an exceptional value for the human innate host defense and lend support to the idea that it evolved to evade bacterial resistance mechanisms targeted at the cationic character of most AMPs. Moreover, they suggest that the antimicrobial activity of dermcidin is dependent on the interaction with the bacterial membrane and might thus assist with the determination of the yet unknown mode of action of this important human AMP.Keywords
This publication has 36 references indexed in Scilit:
- Resistance to dermcidin-derived peptides is independent of bacterial protease activityInternational Journal of Antimicrobial Agents, 2009
- Lipid domains in bacterial membranes and the action of antimicrobial agentsBiochimica et Biophysica Acta (BBA) - Biomembranes, 2008
- Naturally Processed Dermcidin-Derived Peptides Do Not Permeabilize Bacterial Membranes and Kill Microorganisms Irrespective of Their ChargeAntimicrobial Agents and Chemotherapy, 2006
- The co-evolution of host cationic antimicrobial peptides and microbial resistanceNature Reviews Microbiology, 2006
- Monitoring BioluminescentStaphylococcus aureusInfections in Living Mice Using a NovelluxABCDEConstructInfection and Immunity, 2000
- Mechanism of Interaction of Different Classes of Cationic Antimicrobial Peptides with Planar Bilayers and with the Cytoplasmic Membrane ofEscherichia coliBiochemistry, 1999
- Gene replacement in Staphylococcus carnosus and Staphylococcus xylosusFEMS Microbiology Letters, 1997
- Gene replacement in Staphylococcus carnosus and Staphylococcus xylosusFEMS Microbiology Letters, 1997
- Inducible production and cellular location of the epidermin biosynthetic enzyme EpiB using an improved staphylococcal expression systemFEMS Microbiology Letters, 1996
- A RAPID METHOD OF TOTAL LIPID EXTRACTION AND PURIFICATIONCanadian Journal of Biochemistry and Physiology, 1959