Campylobacter growth rates in four different matrices: broiler caecal material, live birds, Bolton broth, and brain heart infusion broth.

BACKGROUND: The objective of this study was to characterise Campylobacter growth in enrichment broths (Bolton broth, brain heart infusion broth), caecal material (in vitro), and in the naturally infected live broilers (in vivo) in terms of mean lag periods and generation times as well as maximum growth rates and population (cell concentration) achieved. METHODS: Bolton and brain heart infusion broths and recovered caecal material were inoculated with 10 poultry strains of Campylobacter (eight Campylobacter jejuni and two Campylobacter coli), incubated under microaerobic conditions, and Campylobacter concentrations determined periodically using the ISO 10272:2006 method. Caeca from 10 flocks, infected at first thinning, were used to characterise Campylobacter growth in the live birds. Mean generation times (G) (early lag to exponential phase) were calculated using the formula: G=t/3.3 logb/B. Mean lag times and µmax were calculated using the Micro Fit(©) Software (Version 1.0, Institute of Food Research). Statistical comparison was performed using GENSTAT ver. 14.1 (VSN International Ltd., Hemel, Hempstead, UK). RESULTS: The mean lag periods in Bolton broth, brain heart infusion broth, caecal material, and in the live bird were estimated to be 6.6, 6.7, 12.6, and 31.3 h, respectively. The corresponding mean generation times were 2.1, 2.2, 3.1, and 6.7 h, respectively; maximum growth rates were 0.7, 0.8, 0.4, and 2 generations h(-1) and the maximum populations obtained in each matrix were 9.6, 9.9, 7.8, and 7.4 log10 CFU/g, respectively. CONCLUSION: This study provides data on the growth of Campylobacter in a range of laboratory media, caecal contents, and in broilers which may be used to develop predictive models and/or inform science-based control strategies such as the maximum time between flock testing and slaughter, logistical slaughter, and single-stage depopulation of broiler units.

Public funding for research on antibacterial resistance in the JPIAMR countries, the European Commission, and related European Union agencies: a systematic observational analysis.

BACKGROUND: Antibacterial resistant infections are rising continuously, resulting in increased morbidity and mortality worldwide. With no new antibiotic classes entering the market and the possibility of returning to the pre-antibiotic era, the Joint Programming Initiative on Antimicrobial Resistance (JPIAMR) was established to address this problem. We aimed to quantify the scale and scope of publicly funded antibacterial resistance research across JPIAMR countries and at the European Union (EU) level to identify gaps and future opportunities. METHODS: We did a systematic observational analysis examining antibacterial resistance research funding. Databases of funding organisations across 19 countries and at EU level were systematically searched for publicly funded antibacterial resistance research from Jan 1, 2007, to Dec 31, 2013. We categorised studies on the basis of the JPIAMR strategic research agenda's six priority topics (therapeutics, diagnostics, surveillance, transmission, environment, and interventions) and did an observational analysis. Only research funded by public funding bodies was collected and no private organisations were contacted for their investments. Projects in basic, applied, and clinical research, including epidemiological, public health, and veterinary research and trials were identified using keyword searches by organisations, and inclusion criteria were based on the JPIAMR strategic research agenda's six priority topics, using project titles and abstracts as filters. FINDINGS: We identified 1243 antibacterial resistance research projects, with a total public investment of €1·3 billion across 19 countries and at EU level, including public investment in the Innovative Medicines Initiative. Of the total amount invested in antibacterial resistance research across the time period, €646·6 million (49·5%) was invested at the national level and €659·2 million (50·5%) at the EU level. When projects were classified under the six priority topics we found that 763 (63%) of 1208 projects funded at national level were within the area of therapeutics, versus 185 (15%) in transmission, 131 (11%) in diagnostics, 53 (4%) in interventions, and only 37 (3%) in environment and 39 (3%) in surveillance. INTERPRETATION: This was the first systematic analysis of research funding of antibacterial resistance of this scale and scope, which relied on the availability and accuracy of data from organisations included. Large variation was seen between countries both in terms of number of projects and associated investment and across the six priority topics. To determine the future direction of JPIAMR countries a clear picture of the funding landscape across Europe and Canada is needed. Countries should work together to increase the effect of research funding by strengthening national and international coordination and collaborations, harmonising research activities, and collectively pooling resources to fund multidisciplinary projects. The JPIAMR have developed a publicly available database to document the antibacterial resistance research collected and can be used as a baseline to analyse funding from 2014 onwards. FUNDING: JPIAMR and the European Commission.

Alterations in presenilin 1 processing by amyloid-beta peptide in the rat retina.

Accumulating evidence indicates that mutations in the presenilin 1 (PS1) gene are responsible for most cases of familial Alzheimer's disease (AD). Although its biological functions are not yet fully understood, it appears that PS1 plays a role in the processing and trafficking of the amyloid precursor protein (APP). However, little is known about factors that are involved in regulating the metabolism of PS1 especially in relation to AD pathology. In this study, we have examined the effect of optic nerve crush, intravitreal injection of the inflammatory agent lipopolysaccharide (LPS) or injection of amyloid beta(1-42) (A beta(1-42)) on the expression and processing of PS1 in the rat retina. We found that 48 h after injection of A beta(1-42) there was a dramatic alteration in the banding pattern of PS1 on Western blots, as indicated by marked changes in the levels of expression of some of its C- and N-terminal fragments in retinal homogenates. These results suggest an A beta(1-42)-induced potentiation of a non-specific stress-related but inflammation-independent alteration of processing of PS1 in this in vivo model.

The farnesoid X receptor is expressed in breast cancer and regulates apoptosis and aromatase expression.

Bile acids are present at high concentrations in breast cysts and in the plasma of postmenopausal women with breast cancer. The farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily that regulates bile acid homeostasis. FXR was detected in normal and tumor breast tissue, with a high level of expression in ductal epithelial cells of normal breast and infiltrating ductal carcinoma cells. FXR was also present in the human breast carcinoma cells, MCF-7 and MDA-MB-468. Activation of FXR by high concentrations of ligands induced MCF-7 and MDA-MB-468 apoptosis. At lower concentrations that had no direct effect on viability, the FXR agonist GW4064 induced expression of mRNA for the FXR target genes, small heterodimer partner (SHP), intestinal bile acid binding protein, and multidrug resistance-associated protein 2 (MRP-2), and repressed the expression of the SHP target gene aromatase. In contrast to MRP-2, mRNA for the breast cancer target genes MDR-3, MRP-1, and solute carrier transporter 7A5 were decreased. Although multidrug resistance transporters were regulated and are known FXR target genes, GW4064 had no effect on the cell death induced by the anticancer drug paclitaxel. Our findings show for the first time that FXR is expressed in breast cancer tissue and has multiple properties that could be used for the treatment of breast cancer.

Expression and activation of the farnesoid X receptor in the vasculature.

The farnesoid X receptor/bile acid receptor (FXR) is a recently discovered member of the nuclear hormone superfamily. FXR ligands have been proposed as targets in cardiovascular disease, regulating cholesterol metabolism and bile acid transport and metabolism in the liver and gastrointestinal tract. When we used a human cardiovascular tissue array, we found that FXR is expressed in a variety of normal and pathological human tissue. Particularly high levels of FXR were found in the vasculature and in a number of different metastatic cancers, as well as the previously identified target tissues of the liver, small intestine, and kidney. In vitro, FXR is present in rat and human vascular smooth muscle cells. When treated with a range of FXR ligands, vascular smooth muscle cells undergo apoptosis in a manner that correlates with the ligands' ability to activate FXR. Furthermore, FXR activators induce mRNA for the FXR target genes, phospholipid transfer protein, and the small heterodimer partner. FXR therefore is a functional protein in the vasculature that may provide a direct target for the treatment of proliferative and dyslipidaemic diseases.

Up-regulation of soluble amyloid precursor protein fragment secretion in the rat retina in vivo by metabotropic glutamate receptor stimulation.

Using the novel rat retinal-vitreal model we have investigated the effect of metabotropic glutamate receptor activation on amyloid precursor protein (APP) metabolism. The release of low mol. wt fragments of APP, at 15-23 kDa in particular, was markedly up-regulated by the metabotropic glutamate receptor agonist (1S,3R)-1-amino-1,3-cyclopentane dicarboxylic acid ((1S,3R)-ACPD) in a concentration- and time-dependent manner, and this response was blocked by the receptor antagonist (S)-alpha-methyl-4-caboxyphenylglycine ((S)-MCPG). These results, together with the observation of a lack of deleterious effects of (1S,3R)-ACPD on the retinal neurons, support a physiological role of metabotropic glutamate receptors in mediating the release of soluble APP fragments, an action which may have important functional and therapeutic implications for Alzheimer's disease.

The antioxidant cocktail, effective microorganism X (EM-X), protects retinal neurons in rats against N-methyl-D-aspartate excitotoxicity in vivo.

Injection of the glutamate agonist N-methyl-D-aspartate (NMDA) into the vitreous body of rats resulted in severe degeneration of neurons in the retina, with a loss of 81% of ganglion cells and 43% of non-ganglion cells. The cocktail EM-X is a novel antioxidant drink derived from ferment of unpolished rice, papaya and sea-weeds with effective microorganisms (EM-X). In animals treated with an intraperitoneal injection of EM-X, the loss of ganglion cells was reduced to 55% and that of non-ganglion cells to 34% when compared to untreated NMDA-injected retinas. Cell degeneration resulting from NMDA excitotoxicity, is thought to be mediated via oxidative stress mechanisms. The neuroprotective effect of the EM-X in this system is therefore likely to be due, at least in part, to its flavonoids, saponins, vitamin E and ascorbic content.

Developmental regulation and possible alternative cleavage of presenilin 1 in the rat retina.

Presenilin 1 (PS1) is a multitransmembrane protein well known for being mutated in most cases of familial Alzheimer's disease. Although its pathological effect is clear, its biological functions are not yet fully understood, but it appears to be involved in development and apoptosis. To investigate the role of PS1 in developmental processes we have studied the expression and proteolytic processing of this protein in the developing rat retina. PS1 appears to be developmentally regulated in the retina, and the pattern of PS1 immunoreactivity is consistent with a role in retinal lamination and pattern formation. Interestingly, no correlation was observed between PS1-positive cells and cells undergoing programmed cell death, suggesting that PS1 does not play a role in apoptosis occurring during this period. Moreover, we observed a change in the pattern of PS1 proteolytic fragments suggestive of a novel alternative cleavage site in the PS1 molecule.

Ergothioneine treatment protects neurons against N-methyl-D-aspartate excitotoxicity in an in vivo rat retinal model.

Injection of the glutamate agonist N-methyl-D-aspartate into the vitreous body of the rat eye resulted in a number of morphological changes in the retina. Most apparent was a dramatic reduction in the density and sizes of neurons accompanied by a decrease in amyloid precursor protein and glial fibrillary acidic protein immunoreactivity. Cell counts revealed that 81% of ganglion cells and 43% of non-ganglion cells were lost as a result of the treatment. However, in animals treated with the antioxidant ergothioneine, these figures dropped to 44 and 31%, respectively. Thus, ergothioneine appears to be neuroprotective in this system and the data suggest that antioxidants may provide a useful means of modulating glutamate-based toxicity.

Amyloid-beta peptide is toxic to neurons in vivo via indirect mechanisms.

We have studied the neurotoxicity of amyloid-beta (Abeta) after a single unilateral intravitreal injection. Within the retina apoptotic cells were seen throughout the photoreceptor layer and the inner nuclear layer but not in the ganglion cell layer at 48 h after injection of Abeta(1-42) compared to vehicle control and control peptide. At 5 months, there was a significant reduction in total cell numbers in the ganglion cell layer in Nissl stained retinas. There was glial cell dysfunction with upregulation of glial fibrillary acidic protein and a reduction in the expression of Müller cell associated proteins in the injected retinas. These results suggest an indirect cytotoxic effect of Abeta on retinal neurons and an important role for dysfunction of Müller glia in mediating Abeta neurotoxicity.