The levels of Brachyspira hyodysenteriae binding to porcine colonic mucins differ between individuals, and binding is increased to mucins from infected pigs with de novo MUC5AC synthesis

Brachyspira hyodysenteriae colonizes the pig colon, resulting in mucohemorrhagic diarrhea and growth retardation. Fecal mucus is a characteristic feature of swine dysentery; therefore, we investigated how the mucin environment changes in the colon during infection with B. hyodysenteriae and how these changes affect this bacterium's interaction with mucins. We isolated and characterized mucins, the main component of mucus, from the colon of experimentally inoculated and control pigs and investigated B. hyodysenteriae binding to these mucins. Fluorescence microscopy revealed a massive mucus induction and disorganized mucus structure in the colon of pigs with swine dysentery. Quantitative PCR (qPCR) and antibody detection demonstrated that the mucus composition of pigs with swine dysentery was characterized by de novo expression of MUC5AC and increased expression of MUC2 in the colon. Mucins from the colon of inoculated and control pigs were isolated by two steps of isopycnic density gradient centrifugation. The mucin densities of control and inoculated pigs were similar, whereas the mucin quantity was 5-fold higher during infection. The level of B. hyodysenteriae binding to mucins differed between pigs, and there was increased binding to soluble mucins isolated from pigs with swine dysentery. The ability of B. hyodysenteriae to bind, measured in relation to the total mucin contents of mucus in sick versus healthy pigs, increased 7-fold during infection. Together, the results indicate that B. hyodysenteriae binds to carbohydrate structures on the mucins as these differ between individuals. Furthermore, B. hyodysenteriae infection induces changes to the mucus niche which substantially increase the amount of B. hyodysenteriae binding sites in the mucus

Epidemiologic evaluation of Vancomycin Resistant genes in Enterococcus spp. isolated from clinical samples

Background & Objectives: Isolation of vancomycin resistant Enterococcus from clinical samples is very important. The aim of this study was evaluation of phenotype and genotype of van genes in vancomycine resistant Enterococcus. Materials and Methods: 411 Enterococcus isolates were collected from selected Tehran’s hospitals between March 2004 and December 2007. The enterococcal isolates were identified by biochemical confirmation tests. Resistance of each isolate to vancomycin determined by disk diffusion and agar dilution test. The presence of the vanA, B, C, D, E resistance gene was assessed by PCR. Results: 185(45%) and 23(5.6%) with disc-diffusion method and agar-dilution method were resistant to vancomucin (VRE) and all of VREs were Enterococcus faecium. 12 (52.2%), 7(30.4%) of the VRE isolates had vanA, vanB and 3(13%) had both of vanA and vanB gene. Conclusion: Most important mechanism for high level resistance to vancomycin is presence of van genes and these genes can transfer between Enterococci. Significance of investigation in molecular level of resistance to vancomycin was due to relation between phenotypic resistant and presence of van genes

In silico prediction of exposure amino acid sequences of outer inflammatory protein A of Helicobacter pylori for surface display on Eschierchia coli

Background: Outer inflammatory protein A (OipA) is an outer membrane protein of Helicobacter pylori that is involved in inducing IL-8 and intracellular signaling. In this study, we have predicted exposure amino acid sequences of OipA for insertion in permissive sites of CstH subunit of Eschierchia coli CS3 pilli for bacterial surface display. Materials and Methods: Databases: National Center for Biotechnology Institute and Protein Data Bank. Servers: PHD, SABLE, GOR 4, SignalP3.0, TBBpred, PRODIV-TMHMM, TMRPres2D, CPH Models, PHYRE, GETAREA, VADAR, Pep state and pep window. Software: Swiss PDB viewer and Discovery studio. Results: In silico prediction of exposure amino acid sequences of OipA led to detection of six sequences of amino acid, 76-87, 106-112, 170-182, 222-230, 242-258, and 278-290. These sequences inserted between amino acid sequences 66-67, 100-101, and 109-110 of CstH that were predicted by Eskandari et al. as permissive sites of CstH. Conclusion: OipA has the ability to induce IL-8 from gastric epithelial cells and some papers are mentioned that this outer membrane protein involve to attachment and intracellular signaling. Receptor of OipA and adhesion motifs on this protein is unknown. Detection of exposure motifs aids to recognition of adhesion motifs and receptor of OipA on gastric epithelial cells. In this study, we have predicted exposure amino acid sequences for insert to subunit CstH of CS3 pilli E. coli for surface display

In silico prediction of exposure amino acid sequences of outer inflammatory protein A of Helicobacter pylori for surface display on Eschierchia coli

Background: Outer inflammatory protein A (OipA) is an outer membrane protein of Helicobacter pylori that is involved in inducing IL-8 and intracellular signaling. In this study, we have predicted exposure amino acid sequences of OipA for insertion in permissive sites of CstH subunit of Eschierchia coli CS3 pilli for bacterial surface display. Materials and Methods: Databases: National Center for Biotechnology Institute and Protein Data Bank. Servers: PHD, SABLE, GOR 4, SignalP3.0, TBBpred, PRODIV-TMHMM, TMRPres2D, CPH Models, PHYRE, GETAREA, VADAR, Pep state and pep window. Software: Swiss PDB viewer and Discovery studio. Results: In silico prediction of exposure amino acid sequences of OipA led to detection of six sequences of amino acid, 76-87, 106-112, 170-182, 222-230, 242-258, and 278-290. These sequences inserted between amino acid sequences 66-67, 100-101, and 109-110 of CstH that were predicted by Eskandari et al. as permissive sites of CstH. Conclusion: OipA has the ability to induce IL-8 from gastric epithelial cells and some papers are mentioned that this outer membrane protein involve to attachment and intracellular signaling. Receptor of OipA and adhesion motifs on this protein is unknown. Detection of exposure motifs aids to recognition of adhesion motifs and receptor of OipA on gastric epithelial cells. In this study, we have predicted exposure amino acid sequences for insert to subunit CstH of CS3 pilli E. coli for surface display

An Entry-Triggering Protein of Ehrlichia Is a New Vaccine Candidate against Tick-Borne Human Monocytic Ehrlichiosis

The incidence of tick-borne diseases has risen dramatically in the past two decades and continues to rise. Discovered in 1986 and designated a nationally notifiable disease in 1998 by the Centers for Disease Control and Prevention, human monocytic ehrlichiosis, which is caused by the bacterium Ehrlichia chaffeensis, is one of the most prevalent, life-threatening, emerging tick-borne zoonoses in the United States. We investigated the role of the E. chaffeensis protein EtpE in transmission of the bacterium from tick to human cells and in vaccinated dogs with EtpE to assess the efficacy of vaccination against E. chaffeensis-infected tick challenge. Our results help fill gaps in our understanding of E. chaffeensis-derived protective antigens that could be used in a candidate vaccine for immunization of humans to counter tick-transmitted ehrlichiosis.Ehrlichia chaffeensis is an obligatory intracellular bacterium that causes human monocytic ehrlichiosis, an emerging disease transmitted by the Lone Star tick, Amblyomma americanum. E. chaffeensis outer membrane protein entry triggering protein of Ehrlichia (EtpE) is necessary for bacterial entry into human cells. We investigated the role of EtpE in transmission of the bacteria from tick to human cells and whether or not vaccination with EtpE can prevent transmission of ehrlichiae from ticks to mammals. An antiserum against the recombinant C terminus of EtpE (rEtpE-C), which binds a mammalian cell-surface receptor and triggers bacterial entry, significantly inhibited E. chaffeensis transmission from infected tick cells to human monocytes in culture. Each of five specific-pathogen-free dogs were vaccinated with rEtpE-C along with an immunostimulating complex or were sham vaccinated with the complex alone. Dogs vaccinated with rEtpE-C developed high antibody titers against rEtpE-C and produced interferon-γ-secreting cells, as assessed with the ELISpot assay. All 10 dogs were challenged with A. americanum adult ticks infected as nymphs by syringe inoculation with E. chaffeensis. Upon challenge, both the vaccinated and control dogs became infected by day 1 post-tick attachment, but the majority of rEtpE-C-vaccinated dogs rapidly cleared the infection from the bloodstream as soon as day 7, whereas most of sham-vaccinated dogs remained infected at day 35. Peripheral blood leukocytes from vaccinated dogs had significantly elevated interferon-γ mRNA levels and secreted significantly elevated interferon-γ soon after tick attachment. Thus, the EtpE-C vaccine represents the first ehrlichial protein vaccine demonstrated to reduce bacterial infection in mammals upon challenge with infected ticks

The disinfecting effect of glutaraldehyde and peracetic acid on tensile load at failure of orthodontic elastomeric chains

Introduction: The purpose of this study was to compare the effect of peracetic acid with glutaraldehyde on tensile load at failure of elastomeric chains after disinfection. Materials & Methods: Tensile load and extension to failure in 30 elastomeric chains were allocated in three groups was measured using Universal Testing Machine. The results were analyzed using ANOVA and Tukey’s post hoc test with a significant level at p<0.05. Results: Glutaraldehyde and peracetic acid decreased the tensile load and elongation to failure of elastomeric chains compared to the control (P=0.03 for tensile load and P=0.01 for extension to failure). There were no significant differences between these two disinfectants (P=0.07 for tensile load and P=0.09 for extension to failure). Conclusion: There tensile load and elongation to failure in chains decreased in both glutaraldehyde and peracetic acid, which is not clinically significant

Isolation and Molecular Analysis of a Novel Neorickettsia Species That Causes Potomac Horse Fever

Despite the detection of Neorickettsia species DNA sequences in various trematode species and their hosts, only three Neorickettsia species have been cell culture isolated and whole-genome sequenced and are known to infect mammals and/or cause disease. The molecular mechanisms that enable the obligatory intracellular bacterium Neorickettsia to colonize trematodes and to horizontally transmit from trematodes to mammals, as well as the virulence factors associated with specific mammalian hosts, are unknown. Potomac horse fever (PHF) is a severe and acute systemic infectious disease of horses, with clinical signs that include diarrhea. Neorickettsia risticii is the only known bacterial species that causes PHF. Ingestion of insects harboring N. risticii-infected trematodes by horses leads to PHF. Our discovery of a new Neorickettsia species that causes PHF and whole-genome sequence analysis of this bacterium will improve laboratory diagnosis and vaccine development for PHF and will contribute to our understanding of Neorickettsia ecology, pathogenesis, and biology.Potomac horse fever (PHF), a severe and frequently fatal febrile diarrheal disease, has been known to be caused only by Neorickettsia risticii, an endosymbiont of digenean trematodes. Here, we report the cell culture isolation of a new Neorickettsia species found in two locations in eastern Ontario, Canada, in 2016 and 2017 (in addition to 10 variable strains of N. risticii) from N. risticii PCR-negative horses with clinical signs of PHF. Gene sequences of 16S rRNA and the major surface antigen P51 of this new Neorickettsia species were distinct from those of all previously characterized N. risticii strains and Neorickettsia species, except for those from an uncharacterized Neorickettsia species culture isolate from a horse with PHF in northern Ohio in 1991. The new Neorickettsia species nonetheless had the characteristic intramolecular repeats within strain-specific antigen 3 (Ssa3), which were found in all sequenced Ssa3s of N. risticii strains. Experimental inoculation of two naive ponies with the new Neorickettsia species produced severe and subclinical PHF, respectively, and the bacteria were reisolated from both of them, fulfilling Koch’s postulates. Serological assay titers against the new Neorickettsia species were higher than those against N. risticii. Whole-genome sequence analysis of the new Neorickettsia species revealed unique features of this bacterium compared with N. risticii. We propose to classify this new bacterium as Neorickettsia finleia sp. nov. This finding will improve the laboratory diagnosis of and vaccine for PHF, environmental risk assessment of PHF, and understanding of PHF pathogenesis and Neorickettsia biology in general

The Repertoire of Glycosphingolipids Recognized by <i>Vibrio cholerae</i>

<div><p>The binding of cholera toxin to the ganglioside GM1 as the initial step in the process leading to diarrhea is nowadays textbook knowledge. In contrast, the knowledge about the mechanisms for attachment of <i>Vibrio cholerae</i> bacterial cells to the intestinal epithelium is limited. In order to clarify this issue, a large number of glycosphingolipid mixtures were screened for binding of El Tor <i>V. cholerae</i>. Several specific interactions with minor complex non-acid glycosphingolipids were thereby detected. After isolation of binding-active glycosphingolipids, characterization by mass spectrometry and proton NMR, and comparative binding studies, three distinct glycosphingolipid binding patterns were defined. Firstly, <i>V. cholerae</i> bound to complex lacto/neolacto glycosphingolipids with the GlcNAcβ3Galβ4GlcNAc sequence as the minimal binding epitope. Secondly, glycosphingolipids with a terminal Galα3Galα3Gal moiety were recognized, and the third specificity was the binding to lactosylceramide and related compounds. <i>V. cholerae</i> binding to lacto/neolacto glycosphingolipids, and to the other classes of binding-active compounds, remained after deletion of the chitin binding protein GbpA. Thus, the binding of <i>V. cholerae</i> to chitin and to lacto/neolacto containing glycosphingolipids represents two separate binding specificities.</p></div