Evaluation of the effect of T regulatory cell depletion and donor BCG vaccination on Mycobacterium tuberculosis H37Ra infection using an in vitro model of human PBMC infection.

This study evaluated the effect of T regulatory cells (Treg cells) and the impact of BCG vaccination history of donors using an in vitro model of Mycobacterium tuberculosis H37Ra infection of peripheral blood mononuclear cells (PBMCs). PBMCs from donors with or without prior BCG vaccination were depleted of Treg cells (PBMCs-Tregs) or not depleted with Treg cells (PBMCs + Tregs) were infected up to 8 days with Mtb H37Ra. Cell aggregates were smaller in PBMCs-Tregs compared to PBMCs + Tregs at day 8 post-infection.

Characterization of immune responses of human PBMCs infected with Mycobacterium tuberculosis H37Ra: Impact of donor declared BCG vaccination history on immune responses and M. tuberculosis growth.

This study characterized the immune responses in early Mycobacterium tuberculosis (Mtb) H37Ra infection of human peripheral blood mononuclear cell (PBMC)-collagen matrix culture and the impact of Bacille Calmette-Guérin (BCG) vaccination history of donor PBMCs on the immune responses to Mtb infection. Aggregates of PBMCs were initially observed on day 3 and the size of aggregates continued to increase on day 8 post-infection, where macrophages and T cell subsets were identified to be present. Similarly, mycobacterial load progressively increased in infected PBMCs during the 8 days of culture but were significantly lower in infected PBMCs from BCG vaccinated (BCG+) donors compared to unvaccinated (BCG-) donors.

Modification of Ganglioside Content of Human Gastric Epithelial Cell Membrane Decreases Helicobacter pylori Adhesion.

Background: In polarized cells, ganglioside location determines ganglioside function. Diet alters ganglioside content and composition in cell membranes. Ganglioside acts as a receptor for Helicobacter pylori.

Understanding the pathophysiology of the human TB lung granuloma using in vitro granuloma models.

Tuberculosis remains a major human health threat that infects one in three individuals worldwide. Infection with Mycobacterium tuberculosis is a standoff between host and bacteria in the formation of a granuloma. This review will introduce a variety of bacterial and host factors that impact individual granuloma fates.

Complete Genome Sequences of Two Helicobacter pylori Strains from a Canadian Arctic Aboriginal Community.

We report here the complete genome sequences of two Amerind Helicobacter pylori strains from Aklavik, Northwest Territories, Canada. One strain contains extra iron-cofactored urease genes and ~140 rearrangements in its chromosome relative to other described strains (typically differing from one another by <10 rearrangements), suggesting that it represents a novel lineage of H. pylori.

A randomized controlled trial comparing sequential with triple therapy for Helicobacter pylori in an Aboriginal community in the Canadian North.

Background: Helicobacter pylori infection occurs more frequently in Arctic Aboriginal settings than elsewhere in North America and Europe. Research aimed at reducing health risks from H pylori infection has been conducted in the Aboriginal community of Aklavik, Northwest Territories.

Objective: To compare the effectiveness of the Canadian standard therapy with an alternative therapy for eliminating H pylori infection in Aklavik.

Genome sequences of 65 Helicobacter pylori strains isolated from asymptomatic individuals and patients with gastric cancer, peptic ulcer disease, or gastritis.

Helicobacter pylori, inhabitant of the gastric mucosa of over half of the world population, with decreasing prevalence in the U.S., has been associated with a variety of gastric pathologies.

Relation of heart rate response to exercise with prognosis and atherosclerotic progression after coronary artery bypass grafting.

Impaired heart rate response to exercise is associated with adverse clinical outcomes in healthy adults and those with established coronary artery disease. It is unclear whether this association persists in subjects who have undergone coronary artery bypass grafting (CABG). In this study, 920 subjects enrolled in the Post CABG trial who had undergone CABG with patent saphenous vein grafts at baseline and known to have discontinued beta blockers before exercise were studied.

Campylobacter jejuni drives MyD88-independent interleukin-6 secretion via Toll-like receptor 2.

Gastrointestinal disease caused by Campylobacter jejuni is characterized by localized inflammation and the destruction of the epithelial cell barrier that forms host innate protection against pathogens. This can lead to an imbalance in fluid transport across the gastrointestinal tract, resulting in severe diarrhea. The mechanisms of host cell receptor recognition of C.

Chimeras of bacterial translation factors Tet(O) and EF-G.

Ribosomal protection proteins (RPPs) confer bacterial resistance to tetracycline by releasing this antibiotic from ribosomes stalled in protein synthesis. RPPs share structural similarity to elongation factor G (EF-G), which promotes ribosomal translocation during normal protein synthesis. We constructed and functionally characterized chimeric proteins of Campylobacter jejuni Tet(O), the best characterized RPP, and Escherichia coli EF-G.

Dietary lipids alter the effect of steroids on the transport of fructose following intestinal resection in rats.

Background: Glucocorticosteroids alter intestinal morphology and transport. We tested the hypothesis that the desired intestinal adaptive response following intestinal resection may be enhanced further by the locally active steroid budesonide, and by feeding a saturated as compared with a polyunsaturated fatty acid diet.

Methods: An in-vitro uptake method was used to assess intestinal fructose uptake by rats of semisynthetic diets enriched in saturated or polyunsaturated fatty acids, and injected with budesonide or control solution.

Species identification of erythromycin-resistant Campylobacter isolates and optimization of a duplex PCR for rapid detection.

This study describes the approach used to verify the species identity of 23 erythromycin-resistant Campylobacter isolates whose identity was initially determined based mainly on the results of the rapid hippurate hydrolysis test or the results of the API-Campy identification system. Species identification of the isolates investigated was confirmed by repeating hippurate hydrolysis using a modification of the rapid hydrolysis test, in addition to performing three genetic-based assays. The original identification was verified in 69.

Antimicrobial susceptibilities of Campylobacter jejuni isolates from poultry from Alberta, Canada.

One hundred four isolates of Campylobacter jejuni from poultry in Alberta, Canada, collected during 2001 were tested for resistance to 10 antimicrobial agents using agar dilution. This study provides a baseline of resistance profiles and the mechanisms of resistance observed in C. jejuni in poultry from Alberta, Canada.

Canadian Helicobacter Study Group Consensus Conference: Update on the approach to Helicobacter pylori infection in children and adolescents--an evidence-based evaluation.

As an update to previously published recommendations for the management of Helicobacter pylori infection, an evidence-based appraisal of 14 topics was undertaken in a consensus conference sponsored by the Canadian Helicobacter Study Group. The goal was to update guidelines based on the best available evidence using an established and uniform methodology to address and formulate recommendations for each topic. The degree of consensus for each recommendation is also presented.

Macrolide resistance in Campylobacter jejuni and Campylobacter coli: molecular mechanism and stability of the resistance phenotype.

A collection of 23 macrolide-resistant Campylobacter isolates from different geographic areas was investigated to determine the mechanism and stability of macrolide resistance. The isolates were identified as Campylobacter jejuni or Campylobacter coli based on the results of the hippurate biochemical test in addition to five PCR-based genotypic methods. Three point mutations at two positions within the peptidyl transferase region in domain V of the 23S rRNA gene were identified.

pVir and bloody diarrhea in Campylobacter jejuni enteritis.

The plasmid pVir may play a role in the virulence of Campylobacter jejuni, a leading cause of bacterial gastroenteritis. The pVir plasmid was identified in 17% of 104 C. jejuni clinical isolates studied and was significantly associated with the occurrence of blood in patient stool, a marker of invasive infection.

Dietary lipids modify intestinal lipid-binding protein RNA abundance in diabetic and control rats.

Background: Lipid-binding proteins have been identified in the enterocyte, including the cytosolic intestinal and liver fatty acid binding proteins (I-FABP and L-FABP, respectively) as well as the brush border membrane fatty acid transporter (FAT). It is unclear whether variations in the type of dietary lipids or diabetes modify the RNA abundance of these proteins. Diabetes is associated with an increased intestinal lipid uptake, and the lipid uptake is greater in rats fed a semisynthetic saturated fatty acid (SFA) as compared with a polyunsaturated fatty acid (PUFA) diet.

Characterization of the DNA adenine 5'-GATC-3' methylase HpyIIIM from Helicobacter pylori.

The effect of inactivation of the 5'-GATC-3' methylase HpyIIIM in Helicobacter pylori (H. pylori) on mismatch repair, adherence, and in vitro fitness was examined. Chromosomal DNA from 90 H.

Stimulating effect of glucocorticosteroids on intestinal fructose transport in rats is increased by feeding a saturated fatty acid diet.

Glucocorticosteroids enhance absorptive functions of the intestine. This study was undertaken to assess the influence of budesonide (BUD), prednisone (PRED), or control vehicle in rats fed either a saturated fatty acid diet (SFA) or a polyunsaturated fatty acid diet (PUFA), on the uptake of sugars. Steroids increased the uptake of fructose, and these effects were greater with SFA than PUFA.

Adaptation following intestinal resection: mechanisms and signals.

The intestine has an inherent ability to adapt morphologically and functionally in response to internal and external environmental changes. The functional adaptations encompass modifications of the brush border membrane fluidity and permeability, as well as up- or down-regulation of carrier-mediated transport. Intestinal adaptation improves the nutritional status following the loss of a major portion of the small intestine, following chronic ingestion of ethanol, following sublethal doses of abdominal irradiation, in diabetes, in pregnancy and lactation, with ageing, and with fasting and malnutrition.

Inhibitory potency of twice-a-day omeprazole on gastric acidity is enhanced by eradication of H. pylori in duodenal ulcer patients.

The gastric pH-elevating effect of proton pump inhibitors such as omeprazole has been reported to be greater in the presence than in the absence of an H. pylori infection. It is unknown if this effect persists when a higher dose of omeprazole is taken.

Effect of steroids on intestinal lipid uptake in rats is enhanced by a saturated fatty acid diet. Cell and molecular biology collaborative network in gastrointestinal physiology.

Glucocorticosteroids enhance sugar digestive and absorptive functions of the intestine, but their effect on lipid uptake is unknown. Modifications in dietary lipids alter the nutrient transport properties of the intestine. The influence of 4 weeks' treatment with budesonide (BUD), prednisone (PRED), or control vehicle in weanling rats fed either an isocaloric semisynthetic saturated fatty acid diet (SFA) or a polyunsaturated fatty acid diet (PUFA), on the uptake of lipids was assessed using everted gut rings.

Multilaboratory comparison of proficiencies in susceptibility testing of Helicobacter pylori and correlation between agar dilution and E test methods.

Susceptibility testing was performed at seven Canadian microbiology laboratories and the Helicobacter Reference Laboratory, Halifax, Nova Scotia, Canada, to assess susceptibility testing proficiency and the reproducibility of the results for clarithromycin and metronidazole and to compare the Epsilometer test (E test) method to the agar dilution reference method. Control strain Helicobacter pylori ATCC 43504 (American Type Culture Collection) and 13 clinical isolates (plus duplicates of four of these strains including ATCC 43504) were tested blindly. The National Committee for Clinical Laboratory Standards (NCCLS) guidelines for agar dilution testing were followed, and the same suspension of organisms was used for agar dilution and E test.

Dietary lipids alter the effect of steroids on transport of glucose after intestinal resection: Part II. Signalling of the response.

Background/purpose: Glucocorticosteroids alter the function of the intestine. Budesonide (Bud) increases the jejunal D-glucose uptake, and this effect is prevented through a polyunsaturated fatty acid (PUFA) diet. This study was undertaken to assess the possible signalling effect of budesonide, prednisone (Pred), or dexamethasone (Dex) in animals with a 50% intestinal resection and fed chow or a diet enriched with saturated (SFA) or polyunsaturated fatty acids.