tellurium and Staphylococcal-Infections

Antibacterial nanoagents with well-controlled structures are greatly desired to address the challenges of bacterial infections. In this study, a featherlike tellurium-selenium heterostructural nanoadjuvant (TeSe HNDs) was created. TeSe HNDs produced

Topics: Anti-Bacterial Agents; Escherichia coli; Humans; Indocyanine Green; Photochemotherapy; Phototherapy; Selenium; Staphylococcal Infections; Tellurium

Nanocolumnar titanium coatings have been fabricated in two sputtering systems with very different characteristics (a laboratory setup and semi-industrial equipment), thus possessing different morphologies (150 nm long columns tilted 20° from the normal and 300 nm long ones tilted 40°, respectively). These coatings exhibit similar antibacterial properties against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) bacteria. When a synergic route is followed and these coatings are functionalized with tellurium (Te) nanorods, the antibacterial properties are enhanced, especially for the long nanocolumns case. The biocompatibility is preserved in all the nanostructured coatings.

Topics: Anti-Bacterial Agents; Coated Materials, Biocompatible; Escherichia coli; Escherichia coli Infections; Humans; Nanostructures; Nanotubes; Staphylococcal Infections; Staphylococcus aureus; Tellurium; Titanium

We have characterized a novel pleiotropic role for CymR, the master regulator of cysteine metabolism. We show here that CymR plays an important role both in stress response and virulence of Staphylococcus aureus. Genes involved in detoxification processes, including oxidative stress response and metal ion homeostasis, were differentially expressed in a DeltacymR mutant. Deletion of cymR resulted in increased sensitivity to hydrogen peroxide-, disulfide-, tellurite- and copper-induced stresses. Estimation of metabolite pools suggests that this heightened sensitivity could be the result of profound metabolic changes in the DeltacymR mutant, with an increase in the intracellular cysteine pool and hydrogen sulfide formation. Since resistance to oxidative stress within the host organism is important for pathogen survival, we investigated the role of CymR during the infectious process. Our results indicate that the deletion of cymR promotes survival of S. aureus inside macrophages, whereas virulence of the DeltacymR mutant is highly impaired in mice. These data indicate that CymR plays a major role in virulence and adaptation of S. aureus for survival within the host.

Topics: Animals; Cell Line; Copper; Cystine; Disulfides; Female; Gene Deletion; Genes, Bacterial; Homeostasis; Hydrogen Peroxide; Macrophages; Mice; Mice, Inbred BALB C; Oxidants; Oxidative Stress; Staphylococcal Infections; Staphylococcus aureus; Tellurium; Up-Regulation; Virulence

The evolution over 30 years of a population of methicillin-resistant Staphylococcus aureus (MRSA) from a tertiary referral hospital was studied by phylogenetic analysis of SmaI-generated restriction fragment length polymorphisms (RFLPs). The results suggest that a new clone of MRSA appeared at the hospital in the early 1980s, which, although usually retaining its ancestral phage-type, developed four different RFLP pulsotypes in the next 16 years. This finding indicates that multiple RFLP patterns in MRSA do not necessarily represent multiple clones deriving from different mec gene transfer events. Such variation within a clone may be significant in the interpretation of RFLP patterns during outbreaks and emphasizes the need to use two typing methods in studies of such populations. Since the appearance of new clones of MRSA is a relatively rare event, cross-infection control is paramount in the prevention of MRSA dissemination.

Topics: Anti-Bacterial Agents; Australia; Bacteriophage Typing; Cross Infection; Culture Media; Deoxyribonucleases, Type II Site-Specific; Electrophoresis, Gel, Pulsed-Field; Gene Transfer Techniques; Hospitals; Humans; Methicillin Resistance; Microbial Sensitivity Tests; Molecular Epidemiology; Phylogeny; Polymorphism, Restriction Fragment Length; Reproducibility of Results; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus Phages; Tellurium

Topics: Coagulase; Humans; Mannitol; Staphylococcal Infections; Staphylococcus; Tellurium; Urinary Tract Infections