The regulation of murein hydrolases is a critical aspect of peptidoglycan growth and metabolism. In the present study, we demonstrate that mutations within the Staphylococcus aureus virulence factor regulatory genes, agr and sar, affect autolysis, resulting in decreased and increased autolysis rates, respectively. Zymographic analyses of these mutant strains suggest that agr and sar exert their...

Abstract Agroforestry systems play an important role in sustainable agroecosystems. However, accurately and adequately quantifying the relationships between environmental factors tree growth these are still lacking. Objectives of this study were to quantify affecting four species develop functional soil maps (FSM) for each agroforestry site. The diameter at breast height, absolute rate (AGR), n...

Abstract Pennate muscle is characterized by fibers that are oriented at a certain angle (pennation angle) relative to the muscle’s line of action and rotation during contraction. This fiber amplifies shortening velocity muscle, match loading conditions without any control system. unique variable gearing mechanism, which Architecture Gear Ratio (AGR), involves complex interaction among three key...

11.1 Proposal In analysing the Tongan data, we proposed the following hypothesis. First, based on the fact that ergativity is manifested also at the level of syntax, we argue that ERG is a structural case. Second, following Bobaljik (1993), we assume that the difference between ergative case marking and accusative case marking is fundamentally the choice of active Agr. If a language chooses Agr...

Quorum sensing via the accessory gene regulator (agr) system has been assigned a central role in the pathogenesis of staphylococci, particularly Staphylococcus aureus. While the control of virulence gene expression in vitro by agr has been relatively straightforward to describe, regulation of both the quorum response itself and virulence genes in vivo is considerably more complex. The quorum re...

More than 200 direct CodY target genes in Staphylococcus aureus were identified by genome-wide analysis of in vitro DNA binding. This analysis, which was confirmed for some genes by DNase I footprinting assays, revealed that CodY is a direct regulator of numerous transcription units associated with amino acid biosynthesis, transport of macromolecules, and virulence. The virulence genes regulate...

This study compared the promoter activation profiles of the 2 major transcripts of the Staphylococcus aureus global regulon, agr (RNAII and RNAIII). In vitro, RNAIII activation temporally followed RNAII activation and was absent in agr mutants. In experimental endocarditis, maximal RNAII activation in vegetations occurred early, followed by progressive increases in RNAIII activation (P<.05; 2 v...

Staphylococcus aureus is both a colonizer of humans and a cause of severe invasive infections. Although the genetic basis for phenotype switching from colonizing to invasive has received significant study, knowledge of host factors that antagonize the switch is limited. We show that VLDL and LDL lipoproteins interfere with this switch by antagonizing the S. aureus agr quorum-sensing system that...