Concordance of Genotyping and Phenotyping in the Classification of Methicillin-Resistant Staphylococcus Aureus

Methicillin-resistant Staphylococcus aureus (MRSA) strains have spread in Saudi Arabia, increasing morbidity, mortality, and financial burdens. Recent studies have suggested the phenotyping methods typically used to classify MRSA as either health care MRSA (HA-MRSA) or community-associated MRSA (CA-MRSA) cases are unreliable, because they lack concordance with the results of genotyping. Yet the expense associated with genotyping precludes its use in the Saudi Aramco population in Saudi Arabia. The absence of a standardized and affordable method to classify MRSA into CA-MRSA and HA-MRSA has been a challenge for infection control programs in Saudi Arabia. The objective of this quantitative, secondary data analysis was to determine the most reliable phenotyping approach to strain identification using John Hopkins Aramco hospital data. The ecological and antibiotics selection pressure theories framed this research. The results of concordance, and sensitivity and specificity tests, suggested hospital admission profiles and susceptibility pattern were the most reliable phenotypic predictors of genotype-based classifications. Multiple logistic regression for susceptibility pattern (OR = 15.47, p \u3c .001) and hospital admission profile (OR = 2.87, p = .008) confirmed those results, whereas all other variables were not found to be statistically significant. These results can be used to clarify the epidemiological and molecular factors that affect the transition of MRSA from health care facilities to the Saudi Aramco community. Implications for positive social change include faster and more reliable classification of MRSA to aid in disease surveillance and the selection of appropriate treatments to reduce MRSA-related morbidity and mortality

Iron corrosion inhibition by olive mill wastewaters in acid medium

In this paper, the effect of olive mill wastewater (OMW) as corrosion inhibitor for iron in molar hydrochloride solution was investigated by using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques. As results, both used techniques gave nearly the same efficiency of inhibition. Polarisation curves indicated that the OMW act as mixed inhibitor without variation of the hydrogen reduction mechanism. The inhibition efficiency increases by increasing OMW concentration to reach a maximum value of 84% at 4ppm. The effect of temperature on the corrosion of iron has also been studied without and with the inhibitor in the range from 298 to 318K. It was found that the rate of corrosion increases with temperature. OMW was adsorbed on the iron surface according to the model of the Langmuir adsorption isotherm. 

Molecular aspects of MERS-CoV

This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Middle East respiratory syndrome coronavirus (MERS-CoV) is a betacoronavirus which can cause acute respiratory distress in humans and is associated with a relatively high mortality rate. Since it was first identified in a patient who died in a Jeddah hospital in 2012, the World Health Organization has been notified of 1735 laboratory-confirmed cases from 27 countries, including 628 deaths. Most cases have occurred in Saudi Arabia. MERS-CoVancestors may be found in OldWorld bats of the Vespertilionidae family. After a proposed bat to camel switching event, transmission of MERS-CoV to humans is likely to have been the result of multiple zoonotic transfers from dromedary camels. Human-to-human transmission appears to require close contact with infected persons, with outbreaks mainly occurring in hospital environments. Outbreaks have been associated with inadequate infection prevention and control implementation, resulting in recommendations on basic and more advanced infection prevention and control measures by the World Health Organization, and issuing of government guidelines based on these recommendations in affected countries including Saudi Arabia. Evolutionary changes in the virus, particularly in the viral spike protein which mediates virus-host cell contact may potentially increase transmission of this virus. Efforts are on-going to identify specific evidence-based therapies or vaccines. The broad-spectrum antiviral nitazoxanide has been shown to have in vitro activity against MERS-CoV. Synthetic peptides and candidate vaccines based on regions of the spike protein have shown promise in rodent and non-human primate models. GLS-5300, a prophylactic DNA-plasmid vaccine encoding S protein, is the first MERS-CoV vaccine to be tested in humans, while monoclonal antibody, m336 has given promising results in animal models and has potential for use in outbreak situations

On the Importance of Registers for Computability

All consensus hierarchies in the literature assume that we have, in addition to copies of a given object, an unbounded number of registers. But why do we really need these registers? This paper considers what would happen if one attempts to solve consensus using various objects but without any registers. We show that under a reasonable assumption, objects like queues and stacks cannot emulate the missing registers. We also show that, perhaps surprisingly, initialization, shown to have no computational consequences when registers are readily available, is crucial in determining the synchronization power of objects when no registers are allowed. Finally, we show that without registers, the number of available objects affects the level of consensus that can be solved. Our work thus raises the question of whether consensus hierarchies which assume an unbounded number of registers truly capture synchronization power, and begins a line of research aimed at better understanding the interaction between read-write memory and the powerful synchronization operations available on modern architectures.Comment: 12 pages, 0 figure

Protective effect of bacterial lipopolysaccharides in the grapevine- Agrobacterium vitis interaction

Cell-associated lipopolysaccharides (LPS) were extracted by the phenol-chloroform-petroleum ether extraction method (PCP) from a nopaline strain of Agrobacterium vitis, purified by treatment with DNase/RNase, proteinase K and dialysis, characterized by polyacrylamide gel electrophoresis (SDS-PAGE), and bioassayed on grapevine shoot nodal segments. LPS preparation used for the experiments in planta was a mixture of rough-type LPS, obtained from precipitation with water after PCP-extraction, and some smooth- and rough-type LPS from the remaining phenol phase. Infiltration of an aqueous dispersion of the mixture in concentrations of 25-1000 µ g.ml-1 did not cause grapevine tissue necrosis, and callus formed within one month. When the LPS dispersions were infiltrated in the grapevine nodal segments, 24 h before challenge inoculation with A. vitis (5x102 cells per 5 µ l droplet), they prevented tumorgenesis and tissue necrosis; but, when the pathogen was inoculated at a higher concentration (5x105 cells per 5 CII droplet), these LS applications were active in protecting plant tissue from necrosis and did not prevent tumor induction. The potential role of LPS as candidate molecules in the protection of grapevine from A. vitis infection is discussed

Investigation of the Effect of Natural Extract on Corrosion Behavior of Tin in Na2CO3 Solution

The inhibition effect of eugenol oil (EO) on the corrosion of tin in 0.1 M Na2CO3 has been studied by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization technics. The effect of temperature on the corrosion behavior of tin in 0.1 M Na2CO3 with and without addition of eugenol oil was studied in the temperature range 278-308 K. This compound inhibits the corrosion of tin at low concentration. At 4g/L eugenol oil the inhibition efficiency calculated by potentiodynamic polarization and EIS techniques is 70% and 82%, respectively. The inhibition efficiency increased with increase of the inhibitor concentration and decreased with increase of medium temperature. Electrochemical impedance spectroscopy was used to investigate the mechanism of corrosion inhibition. Polarization curves reveal that EO acts as a mixed-type inhibitor in corrosive solution. The results obtained from the different corrosion evaluation techniques are in good agreement