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

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

Thermal Dileptons at LHC

We predict dilepton invariant-mass spectra for central 5.5 ATeV Pb-Pb collisions at LHC. Hadronic emission in the low-mass region is calculated using in-medium spectral functions of light vector mesons within hadronic many-body theory. In the intermediate-mass region thermal radiation from the Quark-Gluon Plasma, evaluated perturbatively with hard-thermal loop corrections, takes over. An important source over the entire mass range are decays of correlated open-charm hadrons, rendering the nuclear modification of charm and bottom spectra a critical ingredient.Comment: 2 pages, 2 figures, contributed to Workshop on Heavy Ion Collisions at the LHC: Last Call for Predictions, Geneva, Switzerland, 14 May - 8 Jun 2007 v2: acknowledgment include

Forward Neutron Production at the Fermilab Main Injector

We have measured cross sections for forward neutron production from a variety of targets using proton beams from the Fermilab Main Injector. Measurements were performed for proton beam momenta of 58 GeV/c, 84 GeV/c, and 120 GeV/c. The cross section dependence on the atomic weight (A) of the targets was found to vary as $A^(alpha)$ where $\alpha$ is $0.46\pm0.06$ for a beam momentum of 58 GeV/c and 0.54$\pm$0.05 for 120 GeV/c. The cross sections show reasonable agreement with FLUKA and DPMJET Monte Carlos. Comparisons have also been made with the LAQGSM Monte Carlo.Comment: Accepted for publication in Physical Review D. This version incorporates small changes suggested by referee and small corrections in the neutron production cross sections predicted by FLUK