ANTIBACTERIAL & ANTIFUNGAL POTENTIALITY OF RICINUS COMMUNIS & COLEUS FORSKOHLII ON SOME HUMAN PATHOGENIC MICROORGANISMS

The objective of the present study was to explore the antibacterial and antifungal activity of two plant extracts (Ricinus communis & Coleus forskohlii) against some selected pathogen (Staphylococcus aureus

Newly discovered Staphylococcus aureus serine hydrolase probe and drug targets

There is an urgent need for new diagnosis and treatment options for the bacterial pathogen Staphylococcus aureus. This review will summarize data on ten recently discovered biofilm-associated serine hydrolases called fluorophosphonate-binding hydrolases (FphA-J). Based on the summarized findings, many of these proteins represent intriguing new targets for probe and drug development

Living bacteria rheology: population growth, aggregation patterns and cooperative behaviour under different shear flows

The activity of growing living bacteria was investigated using real-time and in situ rheology -- in stationary and oscillatory shear. Two different strains of the human pathogen Staphylococcus aureus -- strain COL and its isogenic cell wall autolysis mutant -- were considered in this work. For low bacteria density, strain COL forms small clusters, while the mutant, presenting deficient cell separation, forms irregular larger aggregates. In the early stages of growth, when subjected to a stationary shear, the viscosity of both strains increases with the population of cells. As the bacteria reach the exponential phase of growth, the viscosity of the two strains follow different and rich behaviours, with no counterpart in the optical density or in the population's colony forming units measurements. While the viscosity of strain COL keeps increasing during the exponential phase and returns close to its initial value for the late phase of growth, where the population stabilizes, the viscosity of the mutant strain decreases steeply, still in the exponential phase, remains constant for some time and increases again, reaching a constant plateau at a maximum value for the late phase of growth. These complex viscoelastic behaviours, which were observed to be shear stress dependent, are a consequence of two coupled effects: the cell density continuous increase and its changing interacting properties. The viscous and elastic moduli of strain COL, obtained with oscillatory shear, exhibit power-law behaviours whose exponent are dependent on the bacteria growth stage. The viscous and elastic moduli of the mutant have complex behaviours, emerging from the different relaxation times that are associated with the large molecules of the medium and the self-organized structures of bacteria. These behaviours reflect nevertheless the bacteria growth stage.Comment: 9 pages, 10 figure

Antibacterial Activity of Different Extract of Medicinal Plant Antirrihnum Orontium.

Antirrhinum Orontium is belonging to the family Plantaginacea commonly known as lesser snapdragon which is a flowering plant belong to genus Antirrhinum. It was traditionally used in treatment of Tumor, Eye inflammation and Ulcer. Antirrhinum Orontium is contain mostly tertiary alkaloids bases one of them is identified as 4-methyl-2, 6-naphthyridine and Choline is identified as quaternary base. The recent study is to investigate the antibacterial activity of Ethyl acetate, Dichloromethane, Hexane and Water extracts of Antirrhinum Orontium, against the pathogen like Escherichia coli and Staphylococcus aureus. Both the Soxhlet and Maceration water extract were found most active from the other extract against Escherichia coli and Staphylococcus aureus by using agar well diffusion method. The measured zone of inhibition for Soxhlet water extract is 21±0.05mm and Maceration water extract is 20±0.05mm against gram positive Staphylococcus aureus, while for gram negative Escherichia coli 23±0.05mm is measured for Soxlet and 21±0.05mm measured for Maceration water extract

Plant Extracts: Potential Alternative Treatment for Bovine Mastitis Causing Pathogen Staphylococcus aureus

Bovine mastitis is a significant disease affecting dairy herds worldwide. Mastitis can be characterized by physical, chemical, and bacteriological changes in milk and various pathological changes in the glandular tissues. This disease can invariably affect the health status of cattle and eventually have a direct economic impact on the dairy industry. Mastitis can be caused by the interaction of pathogens and their environment, and one of the disease-causing pathogens, Staphylococcus aureus, remains the leading cause of mastitis. Treatment is directed towards the use of broad-spectrum antimicrobials. However, with the threat of antibiotic-resistant pathogens, alternative treatments are being explored. The use of plants with ethnoveterinary origins can be promising in the search for novel therapeutic regimens. This review focuses on various studies using plant extracts as a possible alternative treatment for this specific bovine-causing pathogen, Staphylococcus aureus. Several studies that were conducted will serve as preliminary data in the development of alternative treatments for bovine mastitis

Thiol-based redox switches in the major pathogen Staphylococcus aureus

Staphylococcus aureus is a major human pathogen, which encounters reactive oxygen, nitrogen, chlorine, electrophile and sulfur species (ROS, RNS, RCS, RES and RSS) by the host immune system, during cellular metabolism or antibiotics treatments. To defend against redox active species and antibiotics, S. aureus is equipped with redox sensing regulators that often use thiol switches to control the expression of specific detoxification pathways. In addition, the maintenance of the redox balance is crucial for survival of S. aureus under redox stress during infections, which is accomplished by the low molecular weight (LMW) thiol bacillithiol (BSH) and the associated bacilliredoxin (Brx)/BSH/bacillithiol disulfide reductase (YpdA)/NADPH pathway. Here, we present an overview of thiol-based redox sensors, its associated enzymatic detoxification systems and BSH-related regulatory mechanisms in S. aureus, which are important for the defense under redox stress conditions. Application of the novel Brx-roGFP2 biosensor provides new insights on the impact of these systems on the BSH redox potential. These thiol switches of S. aureus function in protection against redox active desinfectants and antimicrobials, including HOCl, the AGXX (R) antimicrobial surface coating, allicin from garlic and the naphthoquinone lapachol. Thus, thiol switches could be novel drug targets for the development of alternative redox-based therapies to combat multi-drug resistant S. aureus isolates

Carriage Rates of the Nosocomial Pathogen Staphylococcus aureus in Hospital Workers

In the 1950s, Staphylococcus aureus caused a worldwide epidemic of hospital acquired infections (nosocomial infections). By so doing, this bacterium forced nosocomial infections to be recognized as a major problem in the health care system. In that decade, it was discovered that Staphylococcus aureus is vectored by nurses in three different manners, and that carriage rates increase with length of clinical exposure to sources of the bacteria in the hospital environment. Once subdued by antibiotics, multiple drug resistant strains of Staphylococcus aureus are again causing major nosocomial problems. In 1989, Cookson reported that a direct relationship exists between the degree (not length ) to which a health worker is exposed to a Staphylococcus aureus reservoir and the rate of carrier acquisition. Cookson also found that contrary to traditional thought, nurses became carriers without testing positive for hand contamination. This discovery reveals the versatility of Staphylococcus aureus, and it gives reason for more study dealing with the transmission of this important nosocomial pathogen

Method for measurement of bacillithiol redox potential changes using the Brx-roGFP2 redox biosensor in Staphylococcus aureus

Recent advances in the design of genetically encoded redox biosensors, such as redox-sensitive GFP (roGFP) have facilitated the real-time imaging of the intracellular redox potential in eukaryotic cells at high sensitivity and at spatiotemporal resolution. To increase the specificity of roGFP2 for the interaction with the glutathione (GSH)/ glutathione disulfide (GSSG) redox couple, roGFP2 has been fused to glutaredoxin (Grx) to construct the Grx-roGFP2 biosensor. We have previously designed the related Brx-roGFP2 redox biosensor for dynamic measurement of the bacillithiol redox potential (E-BSH) in the human pathogen Staphylococcus aureus. Here, we describe the detailed method for measurements of the oxidation degree (OxD) of the Brx-roGFP2 biosensor in S. aureus using the microplate reader. In particularly, we provide details for determination of the E-BSH changes during the growth and after oxidative stress. For future biosensor applications at the single cell level, we recommend the design of genome-encoded roGFP2 biosensors enabling stable expression and fluorescence in bacteria. Brx-roGFP2 is specific for measurements of the bacillithiol redox potential in Staphylococcus aureus cells Control samples for fully reduced and oxidized states of Brx-roGFP2 are required for calibration during OxD measurements Easy to measure fluorescence excitation intensities at the 405 and 488 nm excitation maxima using microplate reader