Luciferase Reporter Gene System to Detect Cell Wall Stress Stimulon Induction in Staphylococcus aureus.

Luciferase reporter gene fusions provide an extremely rapid and sensitive tool for measuring the induction or repression of stress responses in bacteria. Staphylococcus aureus activates the expression of a cell wall stress stimulon (CWSS) in response to the inhibition or disruption of cell wall synthesis. The highly sensitive promoter-reporter gene fusion construct psas016 p-luc+ can be used to quantify and compare any changes in CWSS expression levels and induction kinetics.

Biofilm formation by Bacillus subtilis requires an endoribonuclease-containing multisubunit complex that controls mRNA levels for the matrix gene repressor SinR.

Biofilm formation by Bacillus subtilis is largely governed by a circuit in which the response regulator Spo0A turns on the gene for the anti-repressor SinI. SinI, in turn, binds to and inactivates SinR, a dedicated repressor of genes for matrix production. Mutants of the genes ylbF, ymcA and yaaT are blocked in biofilm formation, but the mechanism by which they act has been mysterious.

An Electrostatic Net Model for the Role of Extracellular DNA in Biofilm Formation by Staphylococcus aureus.

Unlabelled: Staphylococcus aureus is an important human pathogen that can form biofilms on various surfaces. These cell communities are protected from the environment by a self-produced extracellular matrix composed of proteins, DNA, and polysaccharide. The exact compositions and roles of the different components are not fully understood.

Mutation in the C-di-AMP cyclase dacA affects fitness and resistance of methicillin resistant Staphylococcus aureus.

Faster growing and more virulent strains of methicillin resistant Staphylococcus aureus (MRSA) are increasingly displacing highly resistant MRSA. Elevated fitness in these MRSA is often accompanied by decreased and heterogeneous levels of methicillin resistance; however, the mechanisms for this phenomenon are not yet fully understood. Whole genome sequencing was used to investigate the genetic basis of this apparent correlation, in an isogenic MRSA strain pair that differed in methicillin resistance levels and fitness, with respect to growth rate.

Staphylococcus aureus mutants lacking the LytR-CpsA-Psr family of enzymes release cell wall teichoic acids into the extracellular medium.

The LytR-CpsA-Psr (LCP) proteins are thought to transfer bactoprenol-linked biosynthetic intermediates of wall teichoic acid (WTA) to the peptidoglycan of Gram-positive bacteria. In Bacillus subtilis, mutants lacking all three LCP enzymes do not deposit WTA in the envelope, while Staphylococcus aureus Δlcp mutants display impaired growth and reduced levels of envelope phosphate. We show here that the S.

Deletion of hypothetical wall teichoic acid ligases in Staphylococcus aureus activates the cell wall stress response.

The Staphylococcus aureus cell wall stress stimulon (CWSS) is activated by cell envelope-targeting antibiotics or depletion of essential cell wall biosynthesis enzymes. The functionally uncharacterized S. aureus LytR-CpsA-Psr (LCP) proteins, MsrR, SA0908 and SA2103, all belong to the CWSS.

Characterization of Methylobacterium strains isolated from the phyllosphere and description of Methylobacterium longum sp. nov.

Methylobacterium strains are abundantly found in the phyllosphere of plants. Morphological, physiological and chemotaxonomical properties of 12 previously isolated strains were analyzed in order to obtain a more detailed overview of the characteristics of phyllosphere colonizing Methylobacterium strains. All strains showed the typical properties of the genus Methylobacterium, including pink pigmentation, facultative methylotrophy, a fatty acid profile dominated by C18:1 ω7c, and a high G+C content of 65 mol % or more.

Induction kinetics of the Staphylococcus aureus cell wall stress stimulon in response to different cell wall active antibiotics.

Background: Staphylococcus aureus activates a protective cell wall stress stimulon (CWSS) in response to the inhibition of cell wall synthesis or cell envelope damage caused by several structurally and functionally different antibiotics. CWSS induction is coordinated by the VraSR two-component system, which senses an unknown signal triggered by diverse cell wall active agents.

Results: We have constructed a highly sensitive luciferase reporter gene system, using the promoter of sas016 (S.