The opportunistic pathogen Staphylococcus aureus has become an increasing threat to public health. While the Agr quorum sensing (QS) system is a master regulator of S. aureus virulence, its dysfunction has been frequently reported to promote bacteremia and mortality in clinical infections. Here we show that the Agr system is involved in persister formation in S. aureus. Mutation of either agrCA...

In this article we report a new, simple, and reliable optical read-out detection method able to assess Rotavirus present in human sera as well as in the viral pollution sources. It is based on the interference of two interferometers used as biophotonic transducers. The method significantly improves the optical label-free biosensing response measuring both, the concentration of the AgR and its c...

Different segments of the reproductive tract of 100 adult, non-pregnant, female African giant rats (AGR) were carefully examined, weighed, and measured. The ovaries were observed to be small, pinkish, and kidney-shaped. The uterus of the AGR was found to be uterus duplex. The live weight of the AGR was 999.7 ± 16.86 g. The weight, length, and width of the ovary were 0.095 ± 0.003 g, 0.750 ± 0.0...

The quorum-sensing inhibitor RIP inhibits staphylococcal TRAP/agr systems and both TRAP- and agr-negative strains are deficient in biofilm formation in vivo, indicating the importance of quorum sensing to biofilms in the host. RIP injected systemically into rats has been found to have strong activity in preventing methicillin-resistant Staphylococcus aureus graft infections, suggesting that RIP...

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...