Infections with the leading nosocomial pathogen Staphylococcus epidermidis are characterized by biofilm development on indwelling medical devices. We demonstrate that the quorum-sensing regulator agr affects the biofilm development of S. epidermidis in an unexpected fashion and is likely involved in promoting biofilm detachment. An isogenic agr mutant showed increased biofilm development and co...

This project concerns the design and fabrication of the Automated Guided Robot (AGR) prototype, utilizing genetic algorithm (GA) as a mainframe in helping the robot to generate a self-understanding of the area of work and mobilization to a destination desired by the user. The main objective of this project is to create and develop a Path Planning Mobile Robot able to avoid obstacles in its path...

We have previously identified mgrA (rat) as a regulator of autolysis in Staphylococcus aureus. Besides its effect on autolytic activity, we recently found alterations in the expression of regulator and target virulence genes in the mgrA mutant. Northern analysis and transcription fusion assays showed that inactivation of mgrA has led to the downregulation of RNAIII of agr and hla and upregulati...

sae is a two-component signal transduction system in Staphylococcus aureus that regulates the expression of many virulence factors at the transcriptional level and appears to act synergistically with agr in some cases. In this study, the interactions between sae and agr have been characterized in some detail. It was found that the sae locus is larger and more complex than originally envisioned,...

The advent of transcription profiling technologies has provided researchers with an unprecedented ability to study biological processes. Accordingly, a custom-made Affymetrix GeneChip, constituting >86% of the Staphylococcus aureus genome, was used to identify open reading frames that are regulated by agr and/or SarA, the two best-studied regulators of the organism's virulence response. RNA ext...

During a global research expedition, more than five hundred marine bacterial strains capable of inhibiting the growth of pathogenic bacteria were collected. The purpose of the present study was to determine if these marine bacteria are also a source of compounds that interfere with the agr quorum sensing system that controls virulence gene expression in Staphylococcus aureus. Using a gene repor...

The recharge efficiency during artificial groundwater (AGR) is reduced primarily by clogging that triggered suspended particles. However, there are loopholes in the current standards of recharge-water quality for control AGR, and threshold values turbidity to prevent have not been reasonably determined. In this study, secondary effluents from wastewater treatment plants (WWTPs) were injected in...

abstract       background and objective: agr is the most important regulatory system for the expression of staphylococcus aureus virulence factors in different conditions. agr acts as a quorum sensing system in this bacterium which is activated by increased cell concentration during the transition from logarithmic growth phase to stationary phase. its role is to upregulate the secretory virulen...