This research has R428 datasheet been supported by a Natural Sciences and Engineering Research Council (NSERC) Discovery grant to C.K.Y. E.M.V. was supported by a Canada Graduate Scholarship from NSERC. “
“Filamentous sulfur bacteria of the genus Thiothrix are able to respire nitrate () under

anaerobic growth. Here, Thiothrix caldifontis (G1T, G3), Thiothrix unzii (A1T, TN) and Thiothrix lacustris AS were shown to be capable of further reduction of nitrite and/or nitrous oxides (denitrification). In particular, in the genomes of these strains, excluding T. unzii TN, the nirS gene encoding periplasmic respiratory nitrite reductase was detected, and for T. lacustris AS the nirS expression was confirmed during anaerobic growth. The nirK gene, coding for an alternative nitrite reductase, and the nrfA gene, encoding nitrite reduction to ammonia, were not found in any investigated strains. All Thiothrix species capable of denitrification possess the cnorB gene encoding cytochrome c-dependent NO reductase but not the qnorB gene coding for quinol-dependent NO reductase. Denitrifying capacity (‘full’ or ‘truncated’) can vary between strains belonging to the same species and correlates with physical-chemical parameters of the environment such as nitrate, hydrogen sulfide find more and oxygen concentrations. Phylogenetic analysis revealed the absence of recent horizontal transfer events for narG and nirS; however, cnorB

was subjected to gene transfer before the separation of modern species from a last common ancestor of the Thiothrix species. “
“Staphylococcus epidermidis is a leading cause of hospital-acquired and biofilm-associated infections. Interactions of peripheral blood mononuclear cells

(PBMCs) and monocyte-derived macrophages with planktonic or biofilm phase S. epidermidis cells were Montelukast Sodium studied. Biofilm phase bacteria exhibited higher attachment, as well as, a 10-fold higher intracellular survival in monocyte-derived macrophages than their planktonic counterparts. Stimulation of PBMCs and monocyte-derived macrophages was performed with live or formalin-fixed bacterial cells. Supernatant concentration of selected cytokines was measured by Luminex®xMAP™ technology at different time points. As compared to planktonic phase, biofilm phase bacteria elicited lower amounts of proinflammatory cytokines and Th1 response cytokines, such as TNFα, IL-12p40, IL-12p70 and IFN-γ, whereas they enhanced production of IL-8, GM-CSF and IL-13. This phenomenon was independent of formalin pretreatment. Taken together, these results may contribute to interpretation of observed silent course of biofilm-associated infections. The skin commensal and opportunistic pathogen Staphylococcus epidermidis is a leading cause of hospital-acquired and biofilm-associated infections. Virulence is mainly attributed to ‘biomaterial surfaces colonization and biofilm formation’ (von Eiff et al., 2002).