Although pneumococcal conjugate vaccines are close to being licensed, a more profound knowledge of the virulence factors responsible for the morbidity and mortality caused by Streptococcus pneumoniae is necessary. This review deals with the major structures of pneumococci involved in the pathogenesis of pneumococcal disease and their interference with the defense mechanisms of the host. It is w...

Model biofilms of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas fluorescens, and Pseudomonas aeruginosa were made on steel and polypropylene substrata. Plaque-resembling biofilms of Streptococcus mutans, Actinomyces viscosus, and Fusobacterium nucleatum were made on saliva-coated hydroxyapatite. The activity of enzymes against bacterial cells in biofilm was measured by fluoresc...

Gum polysaccharides are comprised of different monosaccharide units joined together by O-glycosidic linkages. The structural diversity of different polysaccharides is due to differences in degree of polymerization, monosaccharide composition, chain shapes, and linkage types. Gum polysaccharides are commonly used in both food and nonfood industries as stabilizers, thickening and gelling agents, ...

Exopolysaccharides interfere with the isolation and characterization of plasmid DNA from gram-negative bacteria. To repress capsular polysaccharide production, bacteria were cultured in medium containing bismuth nitrate and sodium salicylate. Rapid removal of other contaminating bacterial surface components was achieved by mild acidic zwitterionic detergent extraction. After treatment, bacteria...

Mycobacterium aurum was susceptible to the antibiotic colistin (polymyxin E),which had an MIC of 5 micrograms/ml and an apparent bactericidal effect at concentrations above 50 micrograms/ml. Treatment of actively growing cells with sublethal concentrations of colistin (15 micrograms/ml) resulted in synchronized cell division once the antibiotic was removed. Under conditions of synchronized cell...

Abstract A continuous-flow Anaerobic/Anoxic/Oxic (A2/O) system was operated at different organic concentrations to systematically investigate the effect on nutrient removal, secretion characteristics of extracellular polymer, phosphorus forms transformation and changes in functional flora this system. The results showed that high loading more conducive promote polymeric substance (EPS), increas...

Ozone is known to add across and cleave carbon-carbon double bonds. Ozonolysis is widely used for the preparation of pharmaceuticals, for bleaching substances and for killing microorganisms in air and water sources. Some polysaccharides and oligosaccharides, such as those prepared using chemical or enzymatic β-elimination, contain a site of unsaturation. We examined ozonolysis of low-molecular-...

S.typhimurium is a gram negative bacterium causing serious enteric or extraintestinal infections in human, cattle and birds. These kinds of infections may lead to some permanent or nonpermanent complications like endophthalmitis, Guillain-Barre syndrome and osteomyelitis . Multi-resistant strains of S.typhimurium have been reported from several countries, and these infections are a major public...