Campylobacter colonization of broiler chickens

Campylobacteriosis is a major cause of bacterial gastroenteritis in man. The primary causative organisms, Campylobacter jejuni and C. coli, colonize the chicken’s gastrointestinal tract and contaminated poultry meat is the primary mode of transmission to humans. This thesis examined factors influencing Campylobacter colonization of the chicken’s gastrointestinal tract and several potential interventions to reduce this. A novel in vivo ligated caecal loop model was developed using terminally anaesthetised broiler chickens. Previously unreported durations of stable anaesthesia, of up to 625 minutes, were achieved. This model was used to study real-time colonization of campylobacters in situ. Different responses of two robustly colonizing Campylobacter strains were noted; C. jejuni HPC5 counts invariably declined, whereas C. coli OR12 was capable of immediate growth within the caeca. The same model was used to test bacteriophage therapy of caeca pre-colonized with C. jejuni HPC5. No replication was observed for phage CP30 during the 6 hours studied. Replication was observed for phage CP20, but no decline of C. jejuni had occurred during the same timeframe. The genome of C. coli OR12 was sequenced to identify factors which contribute to its fitness in colonizing chickens. A large 2,033,093 base pair chromosome was assembled, in addition to three plasmids. The chromosome encodes a complete type VI secretion system and plasmid genes encode type IV secretion proteins. These may contribute to the ability of C. coli OR12 to out-compete other Campylobacter strains, and to resist environmental stresses. Campylobacter coli OR12 grows on aerobically incubated blood agar. Serial aerobic passage increased aerotolerance and peroxide stress resistance but motility, growth rate and cellular morphology were unaffected. Aerotolerance was associated with mutations to genes involved in central and carbohydrate metabolism. Aerotolerance may enhance extra-intestinal survival and transmission between host animals. A colonization model was used to test the effect of a live yeast as a putative competitive exclusion intervention against C. jejuni colonization of broiler chickens. No significant differences in caecal or faecal C. jejuni counts were noted, nor was growth rate or feed conversion efficiency affected by yeast supplementation. Analysis of the Campylobacter phage CP8 genome identified significant sequence identity of protein gp010 with the avian leukocyte receptor CD30 ligand. A plausible pathway exists for gp010 to influence the chicken’s immune response to Campylobacter, which would constitute trans-kingdom signalling. A tissue culture based reporter assay for activation of human CD30 receptor was developed. No significant agonistic or antagonistic activity of gp010 was demonstrated. Further in vitro and in vivo investigation is warranted. Collectively these findings further our knowledge of factors which may influence Campylobacter colonization of chickens and provide novel avenues for investigation

The adoption of lean sigma in a UK longitudinal manufacturing case study

The power and influence of the individual techniques of Lean Production (L.P.) and Six Sigma (S.S.) are well recognised as successful manufacturing Continuous Improvement (C.I.) and Change Management (C.M.) methodologies. Both techniques are able to be successfully introduced and applied in the manufacturing companies of the UK with both techniques having a history of successful performance improvement. The hypothesis the research attempts to test is founded upon the limitations of the independent adoption of the techniques in contrast to the development of a more powerful Lean Sigma synergy, blending both techniques in a combined approach. The tools used individually limit the potential and pace of the manufacturing business development with both improvement systems having hard limits and constraining boundaries that the fundamentalist supporters are unable or unwilling to question. This research aims to prove that the cocktail of the techniques known as Lean Sigma (L.S.) can significantly improve the ability of the manufacturing business to accelerate the C.I. process whilst maintaining a more structured and disciplined roll out process that combines the creative waste reduction of L.P. and the statistical improvement and management techniques of S.S. Breaking down the constraints and hard limits of the individual techniques by harnessing the most powerful and influential elements of the two systems to produce a significantly more holistic C.I. programme that delivers the penetration and flexibility of Lean combined with the structure and rigour of Six Sigma. This research follows the migration from the C.I. methodology of Total Quality Management (T.Q.M.) to the acceptance of Lean Sigma in a UK manufacturing case study and is supported by three satellite UK longitudinal manufacturing case studies. The resultant case study analysis attempts to uncover evidence to defend the criticism that the two techniques are mutually exclusive and furthermore that they have a significant combined and complementary impact on the case study businesses that have accepted the dual attack strategy of Lean Sigma. By the process of becoming partial embedded in each of the case studies the researcher has experienced the longitudinal change process first hand and plotted the nuances in each of the studies, comparing and contrasting the differing approaches to the adoption of the methodologies and the roll out strategies. The findings of the research highlight the increased impact of the combined approach in areas as diverse as workforce commitment, floor space utilisation, machine up time, reduced labour requirements reduced tooling costs, component quality improvements, health and safety advances, process efficiency and cost reduction activity.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Prebiotic Driven Increases in IL-17A Do Not Prevent Campylobacter jejuni Colonization of Chickens

© Copyright © 2020 Flaujac Lafontaine, Richards, Connerton, O’Kane, Ghaffar, Cummings, Fish and Connerton. Worldwide Campylobacter jejuni is a leading cause of foodborne disease. Contamination of chicken meat with digesta from C. jejuni-positive birds during slaughter and processing is a key route of transmission to humans through the food chain. Colonization of chickens with C. jejuni elicits host innate immune responses that may be modulated by dietary additives to provide a reduction in the number of campylobacters colonizing the gastrointestinal tract and thereby reduce the likelihood of human exposure to an infectious dose. Here we report the effects of prebiotic galacto-oligosaccharide (GOS) on broiler chickens colonized with C. jejuni when challenged at either an early stage in development at 6 days of age or 20 days old when campylobacters are frequently detected in commercial flocks. GOS-fed birds had increased growth performance, but the levels of C. jejuni colonizing the cecal pouches were unchanged irrespective of the age of challenge. Dietary GOS modulated the immune response to C. jejuni by increasing cytokine IL-17A expression at colonization. Correspondingly, reduced diversity of the cecal microbiota was associated with Campylobacter colonization in GOS-fed birds. In birds challenged at 6 days-old the reduction in microbial diversity was accompanied by an increase in the relative abundance of Escherichia spp. Whilst immuno-modulation of the Th17 pro-inflammatory response did not prevent C. jejuni colonization of the intestinal tract of broiler chickens, the study highlights the potential for combinations of prebiotics, and specific competitors (synbiotics) to engage with the host innate immunity to reduce pathogen burdens

The impact of intracoronary imaging on PCI outcomes in cases utilising rotational atherectomy: an analysis of 8,417 rotational atherectomy cases from the British Cardiovascular Intervention Society Database

Introduction. There is increasing evidence supporting the use of intracoronary imaging to optimize the outcomes of percutaneous coronary intervention (PCI). However, there are no studies examining the impact of imaging on PCI outcomes in cases utilising rotational atherectomy (RA-PCI). Our study examines the determinants and outcomes of using intracoronary imaging in RA-PCI cases including 12-month mortality. Methods. Using the British Cardiac Intervention Society database, data were analysed on all RA-PCI procedures in the UK between 2007 and 2014. Descriptive statistics and multivariate logistic regressions were used to examine baseline, procedural, and outcome associations with intravascular imaging. Results. Intracoronary imaging was used in 1,279 out of 8,417 RA-PCI cases (15.2%). Baseline covariates associated with significantly more imaging use were number of stents used, smoking history, previous CABG, pressure wire use, proximal LAD disease, laser use, glycoprotein inhibitor use, cutting balloons, number of restenosis attempted, off-site surgery, and unprotected left main stem (uLMS) PCI. Adjusted rates of in-hospital major adverse cardiac/cerebrovascular events (IH-MACCE), its individual components (death, peri-procedural MI, stroke, and major bleed), or 12-month mortality were not significantly altered by the use of imaging in RA-PCI. However, subgroup analysis demonstrated a signal towards reduction in 12-month mortality in uLMS RA-PCI cases utilising intracoronary imaging (OR 0.67, 95% CI 0.44–1.03). Conclusions. Intracoronary imaging use during RA-PCI is associated with higher risk of baseline and procedural characteristics. There were no differences observed in IH-MACCE or 12-month mortality with intracoronary imaging in RA-PCI

Novel anti-tumour necrosis factor receptor-1 (TNFR1) domain antibody prevents pulmonary inflammation in experimental acute lung injury.

BACKGROUND: Tumour necrosis factor alpha (TNF-α) is a pleiotropic cytokine with both injurious and protective functions, which are thought to diverge at the level of its two cell surface receptors, TNFR1 and TNFR2. In the setting of acute injury, selective inhibition of TNFR1 is predicted to attenuate the cell death and inflammation associated with TNF-α, while sparing or potentiating the protective effects of TNFR2 signalling. We developed a potent and selective antagonist of TNFR1 (GSK1995057) using a novel domain antibody (dAb) therapeutic and assessed its efficacy in vitro, in vivo and in a clinical trial involving healthy human subjects. METHODS: We investigated the in vitro effects of GSK1995057 on human pulmonary microvascular endothelial cells (HMVEC-L) and then assessed the effects of pretreatment with nebulised GSK1995057 in a non-human primate model of acute lung injury. We then tested translation to humans by investigating the effects of a single nebulised dose of GSK1995057 in healthy humans (n=37) in a randomised controlled clinical trial in which subjects were subsequently exposed to inhaled endotoxin. RESULTS: Selective inhibition of TNFR1 signalling potently inhibited cytokine and neutrophil adhesion molecule expression in activated HMVEC-L monolayers in vitro (P<0.01 and P<0.001, respectively), and also significantly attenuated inflammation and signs of lung injury in non-human primates (P<0.01 in all cases). In a randomised, placebo-controlled trial of nebulised GSK1995057 in 37 healthy humans challenged with a low dose of inhaled endotoxin, treatment with GSK1995057 attenuated pulmonary neutrophilia, inflammatory cytokine release (P<0.01 in all cases) and signs of endothelial injury (P<0.05) in bronchoalveolar lavage and serum samples. CONCLUSION: These data support the potential for pulmonary delivery of a selective TNFR1 dAb as a novel therapeutic approach for the prevention of acute respiratory distress syndrome. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT01587807

Percutaneous Revascularisation for Ischemic Left Ventricular Dysfunction : Cost-Effectiveness Analysis of the REVIVED-BCIS2 Trial

Background: Percutaneous coronary intervention (PCI) is frequently undertaken in patients with ischemic left ventricular systolic dysfunction (ILVD). The REVIVED-BCIS2 trial concluded that PCI did not reduce the incidence of all-cause death or heart failure (HF) hospitalization, however patients assigned to PCI reported better initial health-related quality of life than those assigned to optimal medical therapy (OMT) alone. The aim of this study was to assess the cost-effectiveness of PCI+OMT compared with OMT alone. Methods: REVIVED-BCIS2 was a prospective, multi-centre UK trial, which randomized patients with severe ILVD to either PCI+OMT or OMT alone. Healthcare resource use (including planned and unplanned revascularizations, medication, device implantation and HF hospitalizations) and health outcomes data (EQ-5D-5L questionnaire) on each patient were collected at baseline and up to 8 years post-randomization. Resource use was costed using publicly available national unit costs. Within trial mean total costs and quality-adjusted life years (QALYs) were estimated from the perspective of the UK health system. Cost-effectiveness was evaluated using estimated mean costs and QALYs in both groups. Regression analysis was used to adjust for clinically relevant predictors. Results: Between 2013 and 2020, 700 patients were recruited (mean age: PCI+OMT=70, OMT=68; male (%): PCI+OMT=87, OMT=88); median follow up was 3.4 years. Over all follow-up, patients undergoing PCI yielded similar health benefits at higher costs compared to OMT alone (PCI+OMT: 4.14 QALYs, £22,352; OMT alone: 4.16 QALYs; £15,569; Difference: -0.015; £6,782). For both groups most health resource consumption occurred in the first 2 years post-randomization. Probabilistic results showed that the probability of PCI being cost-effective was 0. Conclusions: Minimal difference in total QALYs was identified between arms and PCI+OMT was not cost-effective compared to OMT, given its additional cost. A strategy of routine PCI to treat ILVD does not appear to be a justifiable use of healthcare resource in the UK. Clinical Trial Registration: URL: https://clinicaltrials.gov/ Unique Identifier: NCT01920048

Percutaneous Revascularization for Ischemic Ventricular Dysfunction : Rationale and Design of the REVIVED-BCIS2 Trial: Percutaneous Coronary Intervention for Ischemic Cardiomyopathy

OBJECTIVES: Evaluate whether PCI in combination with optimal medical therapy (OMT) will reduce all-cause death and hospitalization for HF compared to a strategy of OMT alone. BACKGROUND: Ischemic cardiomyopathy (ICM) is the most common cause of heart failure (HF) and is associated with significant mortality and morbidity. Surgical revascularization has been shown to improve long-term outcomes in some patients, but surgery itself carries a major early hazard. Percutaneous coronary intervention (PCI) may allow a better balance between risk and benefit. METHODS: REVIVED-BCIS2 is a prospective, multi-center, open-label, randomized controlled trial, funded by the National Institute for Health Research in the United Kingdom. Follow-up will be for at least 2 years from randomization. Secondary outcomes include left ventricular ejection fraction (LVEF), quality of life scores, appropriate implantable cardioverter defibrillator therapy and acute myocardial infarction. Patients with LVEF ≤35%, extensive coronary disease and demonstrable myocardial viability are eligible for inclusion and those with a myocardial infarction within 4 weeks, decompensated HF or sustained ventricular arrhythmias within 72 h are excluded. A trial of 700 patients has more than 85% power to detect a 30% relative reduction in hazard. RESULTS: A total of 400 patients have been enrolled to date. CONCLUSIONS: International guidelines do not provide firm recommendations on the role of PCI in managing severe ICM, because of a lack of robust evidence. REVIVED-BCIS2 will provide the first randomized data on the efficacy and safety of PCI in ICM and has the potential to inform guidelines pertaining to both revascularization and HF. (Study of Efficacy and Safety of Percutaneous Coronary Intervention to Improve Survival in Heart Failure [REVIVED-BCIS2]; NCT01920048) (REVascularisation for Ischaemic VEntricular Dysfunction; ISRCTN45979711)

The role of c-FLIP splice variants in urothelial tumours

Deregulation of apoptosis is common in cancer and is often caused by overexpression of anti-apoptotic proteins in tumour cells. One important regulator of apoptosis is the cellular FLICE-inhibitory protein (c-FLIP), which is overexpressed, for example, in melanoma and Hodgkin's lymphoma cells. Here, we addressed the question whether deregulated c-FLIP expression in urothelial carcinoma impinges on the ability of death ligands to induce apoptosis. In particular, we investigated the role of the c-FLIP splice variants c-FLIPlong (c-FLIPL) and c-FLIPshort (c-FLIPS), which can have opposing functions. We observed diminished expression of the c-FLIPL isoform in urothelial carcinoma tissues as well as in established carcinoma cell lines compared with normal urothelial tissues and cells, whereas c-FLIPS was unchanged. Overexpression and RNA interference studies in urothelial cell lines nevertheless demonstrated that c-FLIP remained a crucial factor conferring resistance towards induction of apoptosis by death ligands CD95L and TRAIL. Isoform-specific RNA interference showed c-FLIPL to be of particular importance. Thus, urothelial carcinoma cells appear to fine-tune c-FLIP expression to a level sufficient for protection against activation of apoptosis by the extrinsic pathway. Therefore, targeting c-FLIP, and especially the c-FLIPL isoform, may facilitate apoptosis-based therapies of bladder cancer in otherwise resistant tumours