The Interaction of Antimicrobial Peptides with the Membrane and Intracellular Targets of Staphylococcus aureus Investigated by ATP Leakage, DNA-Binding Analysis, and the Expression of a LexA-Controlled Gene, recA.

The analysis of how antimicrobial peptides (AMPs) interact with bacterial membranes and intracellular targets is important for our understanding of how these molecules affect bacteria. Increased knowledge may aid the design of AMPs that work on their target bacterium without inducing bacterial resistance. Here, we describe different methods to investigate the mode of action of peptides against the Gram-positive bacterium Staphylococcus aureus.

The lysine-peptoid hybrid LP5 maintain activity under physiological conditions and affects virulence gene expression in Staphylococcus aureus.

The antimicrobial peptide, LP5, is a lysine-peptoid hybrid, with antimicrobial activity against clinically relevant bacteria. Here, we investigated how various environmental conditions affect the antimicrobial activity of LP5 against Staphylococcus aureus (S. aureus).

Amphibian antimicrobial peptide fallaxin analogue FL9 affects virulence gene expression and DNA replication in Staphylococcus aureus.

The rapid rise in antibiotic-resistant pathogens is causing increased health concerns, and consequently there is an urgent need for novel antimicrobial agents. Antimicrobial peptides (AMPs), which have been isolated from a wide range of organisms, represent a very promising class of novel antimicrobials. In the present study, the analogue FL9, based on the amphibian AMP fallaxin, was studied to elucidate its mode of action and antibacterial activity against the human pathogen Staphylococcus aureus.

The antimicrobial lysine-peptoid hybrid LP5 inhibits DNA replication and induces the SOS response in Staphylococcus aureus.

Background: The increase in antibiotic resistant bacteria has led to renewed interest in development of alternative antimicrobial compounds such as antimicrobial peptides (AMPs), either naturally-occurring or synthetically-derived. Knowledge of the mode of action (MOA) of synthetic compounds mimicking the function of AMPs is highly valuable both when developing new types of antimicrobials and when predicting resistance development. Despite many functional studies of AMPs, only a few of the synthetic peptides have been studied in detail.

The heme sensing response regulator HssR in Staphylococcus aureus but not the homologous RR23 in Listeria monocytogenes modulates susceptibility to the antimicrobial peptide plectasin.

Background: Host defence peptides (HDPs), also known as antimicrobial peptides (AMPs), have emerged as potential new therapeutics and their antimicrobial spectrum covers a wide range of target organisms. However, the mode of action and the genetics behind the bacterial response to HDPs is incompletely understood and such knowledge is required to evaluate their potential as antimicrobial therapeutics. Plectasin is a recently discovered HDP active against Gram-positive bacteria with the human pathogen, Staphylococcus aureus (S.

Searching for small σB-regulated genes in Staphylococcus aureus.

In recent years, small RNAs (sRNAs) have been identified as important regulators of gene expression in bacteria. Most sRNAs are encoded from intergenic regions and are only expressed under highly specific growth conditions. In Staphylococcus aureus, the alternative sigma factor, σ(B), is known to contribute to the overall stress response, antibiotic resistance, and virulence.

The two-component system CesRK controls the transcriptional induction of cell envelope-related genes in Listeria monocytogenes in response to cell wall-acting antibiotics.

The two-component system CesRK of Listeria monocytogenes responds to cell wall-acting antibiotics. We show here that CesRK controls the transcription of several cell envelope-related genes. The CesRK-dependent induction of these genes may be viewed as an attempt by L.