Ante mortem comparative evaluation of different ELISA systems for diagnosis of porcine Salmonella lnfantis infection

Salmonellosis is one of the most important enteric mfections in man and in livestock. Various serotypes of Salmonella entenca can cause a vanety of clinical and subclinical infections, which are mamly self-limiting gastroenteritis or systemic d1seases. Beside Salmonella (S) Typhimurium, S. Derby and S. lnfantis are the most important cause of porcine Salmonella infections. Although pigs usually do not develop clinical salmonellosis, they become carriers and shedders resulting in a substantial disease-causing potential for humans via meat and faeces

Methicillin-sensitive and Methicillin-resistant Staphylococcus aureus in pigs: (co-) colonization dynamics and clonal diversity

Methicillin-susceptible Staphylococcus (S.) aureus (MSSA) and methicillin-resistant S. aureus (MRSA) are colonizers of skin and mucosa. In humans, MSSA and MRSA compete for colonization space in the anterior nares and one clone can be found rather than differing types of MSSA and MRSA. We investigated the colonization dynamics and clonality of both, MSSA and MRSA in pigs over a longer time period. Eighteen sows were nasally sampled three times every ten weeks. Additionally, environmental samples were taken. Samples were investigated for MSSA and MRSA, respectively. Spa-typing was done with up to five MRSA and MSSA isolates found per sample and time point; selected isolates were further investigated by microarray. 38.9 % of sows were infrequently MSSA/MRSA co-colonized and 16.7 % were permanent carriers of MSSA. The majority of sows showed a changing colonization status. CC398 and CC9 associated spa-types were exclusively found among MRSA and MSSA, respectively. In 44.4 % of sows at least two different types of MSSA were present at the same time and sample. Strains of the same clonal lineage showed a high genetic identity despite their origin. MSSA of different spa-types but 100 % identical microarray profiles were found in sows and their environment. Our results show that pigs may be colonized with MSSA and MRSA at the same time, i.e. that MSSA/MRSA do not exclude each other in the anterior nares of pigs. Highly identic clones are present in sows and their environment, but pigs can be colonized with different clones at the same time

In vivo efficacy of carvacrol on Campylobacter jejuni prevalence in broiler chickens during an entire fattening period

Carvacrol, a primary constituent of plant essential oils (EOs), and its antimicrobial activity have been the subject of many in vitro studies. Due to an increasing demand for alternative antimicrobials and an emerging number of antibiotic resistant bacteria, the use of essential oils has played a major role in many recent approaches to reduce Campylobacter colonization in poultry before slaughter age. For that purpose, the reducing effect of carvacrol on Campylobacter jejuni prevalence in broilers was determined in vivo in an experimental broiler chicken model during an entire fattening period. Carvacrol was added to the feed in a concentration of 120 mg/kg feed four days post hatch until the end of the trial. In this study, we demonstrated a statistically significant decrease of C. jejuni counts by 1.17 decadic logarithm (log10) most probable number (MPN)/g in cloacal swabs during starter and grower periods (corresponding to a broilers age between 1 and 28 days). Similar results were observed for colon enumeration at the end of the trial where C. jejuni counts were significantly reduced by 1.25 log10 MPN/g. However, carvacrol did not successfully reduce Campylobacter cecal colonization in 33-day-old broilers

Discrimination of Vaccinated and infected Pigs by Salmonella-specific IGa antibodies

Isotype switching from IgM to IgG or IgA leads to generation of high affinity antibodies during the immune response. This phenomenon can be applied for differentiation of early and late infection stages. The purpose of this study was to evaluate the applicability of a newly developed Ig-isotype specific Salmonella antibody ELISA for discrimination between vaccinated and infected pigs. Using this novel ELISA we were able to detect different patterns of Salmonella-specific IgM, IgG and IgA antibodies following immunization with a S. Typhimurium live vaccine or after experimental infection with a nalidixic-acid resistant wild-type strain of S. Typhimurium. Interestingly, Salmonella-specific IgA antibodies represented an excellent tool for the recognition of fresh infection in vaccinated pigs. Under SPF conditions, we were able to discriminate between naive, vaccinated, experimentally infected nonvaccinated, and experimentally infected vaccinated animals. However, the highest specific IgA levels were detected in challenged vaccinated pigs. Preliminary results from field trials support the findings from experiments using SPF animals

Neuronal precursor cells with dopaminergic commitment in the rostral migratory stream of the mouse

Neuroblasts born in the subventricular zone of adult mammals migrate via the rostral migratory stream into the granular cell layer or periglomerular layer of the olfactory bulb to differentiate into interneurons. To analyze if new neurons in the granular cell layer or periglomerular layer have different origins, we inserted a physical barrier into the rostral migratory stream, depleted cell proliferation with cytarabine infusions, labeled newborn cells with bromodeoxyuridine, and sacrificed mice after short-term (0, 2, or 14 days) or long-term (55 or 105 days) intervals. After short-term survival, the subventricular zone and rostral migratory stream rapidly repopulated with bromodeoxyuridine(+) cells after cytarabine-induced depletion. Nestin, glial fibrillary acidic protein and the PAX6 were expressed in bromodeoxyuridine(+) cells within the rostral migratory stream downstream of the physical barrier. After long-term survival after physical barrier implantation, bromodeoxyuridine(+) neurons were significantly reduced in the granular cell layer, but bromodeoxyuridine(+) and dopaminergic neurons in the periglomerular layer remained unaffected by the physical barrier. Thus, newborn neurons for the granular cell layer are mainly recruited from neural stem cells located in the subventricular zone, but new neurons for the periglomerular layer with dopaminergic predisposition can rise as well from neuronal stem or precursor cells in the rostral migratory stream

Prevalence of Campy/obacter spp. and Yersinia enterocolitica in Fattening Pig Herds in Lower Saxony, Germany

The results of a study on the occurrence of two bacteria that cause zoonoses, Campylobacter spp. and Yersmia enterocolilica were presented and the results of bacteriological and serological methods of detection were compared. The study was carried out on 30 fattening herds in Lower Saxony, Germany Bacteriological findings of Campylobacter spp. in the faeces indicated that 69.7% of the fattening pigs were positive, but 81 .2% tested positive serologically. All herds tested here were both bacteriologically and serologically positive for Campylobacter spp. Furthermore, only 8.4 % tested pos1t1ve for Yersinia enterocolitica in the faecal samples, but 66.8 % of the animals were serologically positive for that bacterium. At herd level 43.3 % of the herds tested bactenologically positive for Yersinia enterocolitica, whereas serological testing showed that 83.3 % of the units had one or more reacting animal

Identification of parvalbumin interneurons as cellular substrate of fear memory persistence

Parvalbumin-positive (PV) basket cells provide perisomatic inhibition in the cortex and hippocampus and control generation of memory-related network activity patterns, such as sharp wave ripples (SPW-R). Deterioration of this class of fast-spiking interneurons has been observed in neuropsychiatric disorders and evidence from animal models suggests their involvement in the acquisition and extinction of fear memories. Here, we used mice with neuron type-targeted expression of the presynaptic gain-of-function glycine receptor RNA variant GlyR {beta}3L(185L) to genetically enhance the network activity of PV interneurons. These mice showed reduced extinction of contextual fear memory but normal auditory cued fear memory. They furthermore displayed increase of SPW-R activity in area CA3 and CA1 and facilitated propagation of this particular network activity pattern, as determined in ventral hippocampal slice preparations. Individual freezing levels during extinction and SPW-R propagation were correlated across genotypes. The same was true for parvalbumin immunoreactivity in the ventral hippocampus, which was generally augmented in the GlyR mutant mice and correlated with individual freezing levels. Together, these results identify PV interneurons as critical cellular substrate of fear memory persistence and associated SPW-R activity in the hippocampus. Our findings may be relevant for the identification and characterization of physiological correlates for posttraumatic stress and anxiety disorders

Hard diffraction in hadron--hadron interactions and in photoproduction

Hard single diffractive processes are studied within the framework of the triple--Pomeron approximation. Using a Pomeron structure function motivated by Regge--theory we obtain parton distribution functions which do not obey momentum sum rule. Based on Regge-- factorization cross sections for hard diffraction are calculated. Furthermore, the model is applied to hard diffractive particle production in photoproduction and in $p\bar{p}$ interactions.Comment: 13 pages, Latex, 13 uuencoded figure

Different MAPT haplotypes influence expression of total MAPT in postmortem brain tissue

The MAPT gene, encoding the microtubule-associated protein tau on chromosome 17q21.31, is result of an inversion polymorphism, leading to two allelic variants (H1 and H2). Homozygosity for the more common haplotype H1 is associated with an increased risk for several tauopathies, but also for the synucleinopathy Parkinson's disease (PD). In the present study, we aimed to clarify whether the MAPT haplotype influences expression of MAPT and SNCA, encoding the protein alpha-synuclein (alpha-syn), on mRNA and protein levels in postmortem brains of PD patients and controls. We also investigated mRNA expression of several other MAPT haplotype-encoded genes. Postmortem tissues from cortex of fusiform gyrus (ctx-fg) and of the cerebellar hemisphere (ctx-cbl) of neuropathologically confirmed PD patients (n = 95) and age- and sex-matched controls (n = 81) were MAPT haplotype genotyped to identify cases homozygous for either H1 or H2. Relative expression of genes was quantified using real-time qPCR;soluble and insoluble protein levels of tau and alpha-syn were determined by Western blotting. Homozygosity for H1 versus H2 was associated with increased total MAPT mRNA expression in ctx-fg regardless of disease state. Inversely, H2 homozygosity was associated with markedly increased expression of the corresponding antisense MAPT-AS1 in ctx-cbl. PD patients had higher levels of insoluble 0N3R and 1N4R tau isoforms regardless of the MAPT genotype. The increased presence of insoluble alpha-syn in PD patients in ctx-fg validated the selected postmortem brain tissue. Our findings in this small, but well controlled cohort of PD and controls support a putative biological relevance of tau in PD. However, we did not identify any link between the disease-predisposing H1/H1 associated overexpression of MAPT with PD status. Further studies are required to gain a deeper understanding of the potential regulatory role of MAPT-AS1 and its association to the disease-protective H2/H2 condition in the context of PD

CARD15 genotype and phenotype analysis in 55 pediatric patients with Crohn disease from Saxony, Germany

Objectives: Crohn disease is a chronic inflammatory bowel disorder that is caused by environmental and genetic factors. Mutations in the CARD15 gene have been recently identified to be associated with the disease. Until now no genetic study has focused directly on a pediatric population. Methods: The authors sequenced all 12 exons of the CARD15 gene in 55 pediatric patients with Crohn disease from Saxony. Their average age at onset was 11.2 years (1-17.5 years). The authors also evaluated the genotype-phenotype relationship in the patients. Results: Fourteen different polymorphic and/or disease-related nucleotide alterations have been identified in the patients. Sixty-five percent of their genomic DNA samples harbored at least one of six mutations within the CARD15 gene, which previously has been identified as being associated with Crohn disease. The authors found that the cytosine insertion mutation 3020insC was significantly more common in their pediatric population than in patients with Crohn disease (26% versus 11 % of the alleles) whose results were reported in the literature. The genotype-phenotype analysis showed that the authors' patients with at least one of the six CARD15 disease-associated mutations had a high risk of inflammation located in the terminal ileum and ascending colon. In 10 of 19 patients with two mutations, intestinal resection surgery was necessary because of stricturing. Conclusions: In the authors' pediatric patients, the genetic influence on Crohn disease was more pronounced than that reported in any other study, and it strongly affected the clinical phenotype. (C) 2003 Lippincott Williams Wilkins, Inc