RESUMO
Trichinella spiralis muscle stage larvae (mL1) produce excretory-secreted products (ESPs), a complex mixture of protein, which are believed to be important for establishing or maintaining an infection niche within skeletal muscle and the intestine. Studies of both whole ESPs and individual cloned proteins have shown that some ESPs are potent immunogens capable of eliciting protective immune responses. Here we describe two novel proteins, Secreted from Muscle stage Larvae SML-4 and SML-5 which are 15 kDa and 12 kDa respectively. The genes encoding these proteins are highly conserved within the Trichinellids, are constituents of mL1 ESP and localized in the parasite stichosome. While SML-5 is only expressed in mL1 and early stages of adult nematode development, SML-4 is a tyvosylated glycoprotein also produced by adult nematodes, indicating it may have a function in the enteral phase of the infection. Vaccination with these proteins resulted in an impaired establishment of adult stages and consequently a reduction in the burden of mL1 in BALB/c mice. This suggests that both proteins may be important for establishment of parasite infection of the intestine and are prophylactic vaccine candidates.
Assuntos
Anticorpos Anti-Helmínticos/imunologia , Antígenos de Helmintos/imunologia , Proteínas de Helminto/imunologia , Vacinas Protozoárias/imunologia , Trichinella spiralis/imunologia , Triquinelose/prevenção & controle , Animais , Feminino , Larva/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Músculos/parasitologia , Ratos , Ratos Sprague-Dawley , Células Th1/imunologia , Células Th2/imunologia , Triquinelose/imunologia , Vacinação , Vacinas Sintéticas/imunologiaRESUMO
Demonstrated herein is a single rapid approach employed for synthesis of Ag-graphene nanocomposites, with excellent antibacterial properties and low cytotoxicity, by utilizing a continuous hydrothermal flow synthesis (CHFS) process in combination with p-hexasulfonic acid calix[6]arene (SCX6) as an effective particle stabilizer. The nanocomposites showed high activity against E. coli (Gram-negative) and S. aureus (Gram-positive) bacteria. The materials were characterized using a range of techniques including transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, UV-vis spectrophotometry, FT-IR, and X-ray powder diffraction (XRD). This rapid, single step synthetic approach not only provides a facile means of enabling and controlling graphene reduction (under alkaline conditions) but also offers an optimal route for homogeneously producing and depositing highly crystalline Ag nanostructures into reduced graphene oxide substrate.
Assuntos
Nanocompostos , Antibacterianos , Calixarenos , Escherichia coli , Grafite , Prata , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureusRESUMO
A brief summary of the role of DnaK and GroE chaperones in protein folding precedes a discussion of the role of GroE in Escherichia coli. We consider its obligate substrates, the 8 that are both obligate and essential, and the prospects for constructing a mutant that could survive without it. Structural features of GroE-dependent polypeptides are also considered.
Assuntos
Proteínas de Escherichia coli/química , Escherichia coli/metabolismo , Proteínas de Choque Térmico/química , Dobramento de Proteína , Escherichia coli/química , Proteínas de Escherichia coli/fisiologia , Proteínas de Choque Térmico HSP70/química , Proteínas de Choque Térmico HSP70/fisiologia , Proteínas de Choque Térmico/fisiologia , Estresse Fisiológico , Especificidade por SubstratoRESUMO
Adhesion of bacteria to the mucosal epithelial cell surface is the first step in infection, and studies have shown that inhibition of this step may be useful therapeutically. To test compounds that may prevent bacterial binding to a number of epithelial cell lines, we have developed a high-throughput adhesion assay using a microtitre plate system and bacteria that have been modified to express firefly luciferase. This method has proved to be a sensitive, rapid, and reproducible system for screening antiadhesive agents for their effects on bacterial adhesion.
Assuntos
Aderência Bacteriana/fisiologia , Burkholderia cepacia/fisiologia , Escherichia coli/fisiologia , Pseudomonas aeruginosa/fisiologia , Salmonella typhimurium/fisiologia , Animais , Aderência Bacteriana/efeitos dos fármacos , Burkholderia cepacia/genética , Carboidratos/fisiologia , Células Epiteliais/microbiologia , Escherichia coli/genética , Humanos , Luciferases de Vaga-Lume/genética , Camundongos , Pseudomonas aeruginosa/genética , Salmonella typhimurium/genética , Transformação GenéticaRESUMO
Dihydropicolinate synthase (DHDPS; E.C. 4.2.1.52) catalyses the first committed step of lysine biosynthesis in plants and bacteria. Plant DHDPS enzymes, which are responsible solely for lysine biosynthesis, are strongly inhibited by lysine (I0.5 =10 microM), whereas the bacterial enzymes which are less responsive or insensitive to lysine inhibition have the additional function of meso-diaminopimelate biosynthesis which is required for cell wall formation. Previous studies have suggested that expression of the Escherichia coli dapA gene, encoding DHDPS, is unregulated. We show here that this is not the case and that expression of LacZ from the dapA promoter (PdapA) increases in response to diaminopimelic acid limitation in E. coli K-12.