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Staphylococcus aureus is an opportunistic bacterial pathogen responsible for a diverse spectrum of human diseases and a leading cause of nosocomial and community-acquired infections. Development of a vaccine against this pathogen is an important goal. The fibronectin binding protein A (FnBPA) of S. aureus is one of multifunctional ‘microbial surface components recognizing adhesive matrix molecules' (MSCRAMMs). It is one of the most important adhesin molecules involved in the initial adhesion steps of S. aureus infection. It has been studied as potential vaccine candidates. However, FnBPA is a high-molecular-weight protein of 106 kDa and difficulties in achieving its high-level expression in vitro limit its vaccine application in S. aureus infection diseases control. Therefore, mapping the immunodominant regions of FnBPA is important for developing polyvalent subunit fusion vaccines against S. aureus infections. In the present study, we cloned and expressed the N-terminal and C-terminal of FnBPA. We evaluated the immunogenicity of the two sections of FnBPA and the protective efficacy of the two truncated fragments vaccines in a murine model of systemic S. aureus infection. The results showed recombinant truncated fragment F130-500 had a strong immunogenicity property and survival rates significantly increased in the group of mice immunized with F130-500 than the control group. We futher identified the immunodominant regions of FnBPA. The mouse antisera reactions suggest that the region covering residues 110 to 263 (F1B110-263) is highly immunogenic and is the immunodominant regions of FnBPA. Moreover, vaccination with F1B110-263 can generate partial protection against lethal challenge with two different S. aureus strains and reduced bacterial burdens against non-lethal challenge as well as that immunization with F130-500. This information will be important for further developing anti- S. aureus polyvalent subunit fusion vaccines. [ABSTRACT FROM AUTHOR]

To understand the absorption mechanism of nitrogen dioxide into a sodium sulfide solution, a stirred tank reactor with a plane gas-liquid interface was used to measure the chemical absorption rate of diluted nitrogen dioxide into sodium sulfide solution. The absorption rates under various experimental conditions were measured and the effects of experimental conditions on nitrogen dioxide absorption rate were discussed. The results show that, in the range of this study, nitrogen dioxide absorption rate increases with increasing sodium sulfide concentration, nitrogen dioxide inlet concentration, and flue gas flow rate, but decreases with increasing reaction temperature and oxygen content in flue gas. [ABSTRACT FROM AUTHOR]

The article presents a study that looks into the method on how to acquire the data of virulence and adherence associated genes and polymorphism of Escherichia coli 0157. H7 isolates. The study used the polymerase chain reaction (PCR) assay to determine the measure of gene on 0157: H7 isolates. It reveals the relatively low virulence of 0157 isolates and its being genetically conservative.

Abstract: The effect of gas–liquid phase compositions on NO and NO2 absorption into ammonium-sulfite and bisulfite solutions is investigated. Preliminary experiment results indicate that the concentrations of (NH4)2SO3 or NH4HSO3 solution and the molar ratio for HSO3 − to the total solution concentrations all have significant impact on NO2 and NO absorption rates. While the solution concentration is constant, the absorption of NOx mixture is strongly related to the ratio NO2/NOx. The absorption rate of NO is primarily affected by NO2 inlet concentration, and the NO absorption rate reaches the maximum value in (NH4)2SO3 solution with the increase of NO2 inlet concentration, which is determined by the reaction of NO and NO2 with SO3 2− as well as NO formation. Moreover, when the solution is NH4HSO3 the best ratio of NO2/NO for the maximum value of the NO absorption rate becomes less or smaller. Meanwhile, the presence of NO in the gas phase is also favorable to the absorption rate of NO2 in ammonium-sulfite or bisulfite solutions. The total results suggest that the coexistence of NO and NO2 in the flue gas could enhance the absorption of each other to some extent. [Copyright &y& Elsevier]