Human antimicrobial peptide, LL-37, induces non-inheritable reduced susceptibility to vancomycin in Staphylococcus aureus.

Antimicrobial peptides (AMPs) are central components of the innate immune system providing protection against pathogens. Yet, serum and tissue concentrations vary between individuals and with disease conditions. We demonstrate that the human AMP LL-37 lowers the susceptibility to vancomycin in the community-associated methicillin-resistant S.

The agr quorum sensing system in Staphylococcus aureus cells mediates death of sub-population.

Objective: In the human pathogen, Staphylococcus aureus, the agr quorum sensing system controls expression of a multitude of virulence factors and yet, agr negative cells frequently arise both in the laboratory and in some infections. The aim of this study was to examine the possible reasons behind this phenomenon.

Results: We examined viability of wild type and agr mutant cell cultures using a live-dead stain and observed that in stationary phase, 3% of the wild type population became non-viable whereas for agr mutant cells non-viable cells were barely detectable.

Norlichexanthone Reduces Virulence Gene Expression and Biofilm Formation in Staphylococcus aureus.

Staphylococcus aureus is a serious human pathogen and antibiotic resistant, community-associated strains, such as the methicillin resistant S. aureus (MRSA) strain USA300, continue to spread. To avoid resistance, anti-virulence therapy has been proposed where toxicity is targeted rather than viability.

Reversible antibiotic tolerance induced in Staphylococcus aureus by concurrent drug exposure.

Unlabelled: Resistance of Staphylococcus aureus to beta-lactam antibiotics has led to increasing use of the glycopeptide antibiotic vancomycin as a life-saving treatment for major S. aureus infections. Coinfection by an unrelated bacterial species may necessitate concurrent treatment with a second antibiotic that targets the coinfecting pathogen.