An outbreak of sheep-associated malignant catarrhal fever in sows

his paper describes a case of malignant catarrhal fever in a sow herd in Belgium caused by infection with ovine herpesvirus-2 (OHV-2). The 11 affected sows had high fever and 10 of them died within 3 days after the onset of clinical disease. The most prominent macroscopic lesion was a hemorrhagic to pseudo-membranous gastritis. Histopathology revealed severe infiltration and necrosis of the gastric mucosa. Neither antimicrobial treatment nor injection with anti-inflammatory drugs ameliorated the severity of the disease. As the sows and sheep were housed in the same building with the possibility of having direct nose-to-nose contact, and as PCR testing showed that the virus found in the sows was identical to that found in the sheep, it is very likely that the infection was transmitted from the subclinically infected sheep to the sows. The present case showed that OHV-2 infection should be included in the differential diagnosis when facing problems of fever followed by death, especially when pigs are housed in close contact with sheep

Impact of use of Tylosin and Virginiamycin on antimicrobial agents resistance profiles of Enterococcus spp. and E. coli isolates from swine in field conditions

Enterococcus spp. and E. coli are recognized as indicator microorganisms for the human and animal intestinal flora, and are also known to be potential reservoirs of antimicrobial resistance genes. Among the various use of antimicrobial agents that can promote antibioresistance, on farm use of growth promoters raises public health concerns. The aim of this study was to evaluate the impact of the use of selected growth promoters on antimicrobial resistance profiles of Enterococcus spp. and E. coli isolates from swine in field conditions. Enterococcus and E. coli isolates obtained from pooled fecal samples of pigs receiving Tylosin (44 ppm, n = 100) and Virginiamycin (22 ppm, n=1 00) were compared to isolates obtained from a control group (n = 1 00) fed without growth promoters, in field conditions. Comparison was done between isolates obtatned in the first week of treatment and isolates obtained 1n the 15th week

Evolution of Salmonella excretion by sows during gestation in link with the faecal microbiome

Pork meat is estimated to be responsible of 10 to 20% of human salmonellosis cases. Control strategies at the farm could reduce contamination at the slaughterhouse. One of the targeted sector of the production is the maternity, where sows could be Salmonella reservoirs. The aim of this study was to characterize the faecal microbiome of sows excreting or not Salmonella during gestation phases. A total of 76 sows were selected and fecal matters were analysed at the beginning or the end of gestation period. Salmonella detection was conducted using a method including two selective enrichment media (MSRV and TBG). Nine (9) isolates per positive samples were collected. Among the 76 sows tested, 31 were shedding Salmonella. The sows in the first third of their gestation shed significantly more frequently Salmonella (22/29) than those in the last third (9/47) (χ² P \u3c 0.05). The shedding status of 19 of the sows that were previously sampled in the first third of their gestation was followed, this time in the last third, confirming reduction of the shedding. Association between changes in the intestinal microbiome and this evolution of Salmonella shedding will be explored. MiSeq sequencing is currently being conducted on the feces to identify shifts in the composition or diversity in the microbial community that could be associated to these variations. A large number of Salmonella isolates that were collected were genotyped by a high resolution melt (HRM) technique. These results showed the presence of a major HRM profile (136 isolates / 169) and two minor profiles (24 and 9 /169)

Digestive microbiota changes during application of an effective, feed presentation based, mitigation option against Salmonella shedding in pigs

If some studies have attempted to mitigate the Salmonella spp. excretion in pigs by feed related interventions, none clearly demonstrated the impact of the presentation (mash or pellet and particular size). Thus this study aimed to determine if the modification of the pigs feed presentation alone can lower the Salmonella spp. excretion

The rhomboids: a nearly ubiquitous family of intramembrane serine proteases that probably evolved by multiple ancient horizontal gene transfers

BACKGROUND: The rhomboid family of polytopic membrane proteins shows a level of evolutionary conservation unique among membrane proteins. They are present in nearly all the sequenced genomes of archaea, bacteria and eukaryotes, with the exception of several species with small genomes. On the basis of experimental studies with the developmental regulator rhomboid from Drosophila and the AarA protein from the bacterium Providencia stuartii, the rhomboids are thought to be intramembrane serine proteases whose signaling function is conserved in eukaryotes and prokaryotes. RESULTS: Phylogenetic tree analysis carried out using several independent methods for tree constructions and the corresponding statistical tests suggests that, despite its broad distribution in all three superkingdoms, the rhomboid family was not present in the last universal common ancestor of extant life forms. Instead, we propose that rhomboids evolved in bacteria and have been acquired by archaea and eukaryotes through several independent horizontal gene transfers. In eukaryotes, two distinct, ancient acquisitions apparently gave rise to the two major subfamilies, typified by rhomboid and PARL (presenilins-associated rhomboid-like protein), respectively. Subsequent evolution of the rhomboid family in eukaryotes proceeded by multiple duplications and functional diversification through the addition of extra transmembrane helices and other domains in different orientations relative to the conserved core that harbors the protease activity. CONCLUSIONS: Although the near-universal presence of the rhomboid family in bacteria, archaea and eukaryotes appears to suggest that this protein is part of the heritage of the last universal common ancestor, phylogenetic tree analysis indicates a likely bacterial origin with subsequent dissemination by horizontal gene transfer. This emphasizes the importance of explicit phylogenetic analysis for the reconstruction of ancestral life forms. A hypothetical scenario for the origin of intracellular membrane proteases from membrane transporters is proposed

Impact of mash feeding versus pellets on propionic/butyric acid levels and on total Escherichia coli load in the gastrointestinal tract of growing pigs

Feed characteristics may influence the bacterial community composition and metabolic activities in the pig gastrointestinal tract, known to be associated with positive effects on the gut. Use of mash feed is associated with reduced Salmonella excretion, but little is known of its effect on the Escherichia coli population or of the mechanism of action. Our objectives were to assess the effect of feed texture combined with feed particle size on VFA profiles and levels, total E. coli count, and the presence of genes encoding virulence factors of pathogenic E. coli strains in the digestive tract along with their impact on pig performance of fattening pigs. Pigs (n = 840) on a commercial farm received mash or pellet diets of different particle sizes during the fattening period. Caecal and colon contents from 164 pigs were sampled at the slaughterhouse for enumeration of E. coli by quantitative PCR (qPCR) and for VFA quantification by capillary gas chromatography. The yccT gene was used to enumerate total E. coli. Improved pig performances associated with pellet texture and a 500-μm size were observed. Caecal (P = 0.02) and colon (P < 0.01) propionic acid concentrations were lower for pigs receiving pellet rather than mash feed. Similarly, caecal (P = 0.01) and colon (P < 0.001) butyric acid concentrations were also lower for pigs receiving pellet rather than mash feed, as determined by capillary gas chromatography. Moreover, caecal (P = 0.03) and colon (P < 0.001) butyric acid concentrations were higher for pigs receiving a feed with a 1,250-μm particle size rather than a 500-μm particle size. On the other hand, total caecal and colon E. coli levels were higher for pigs receiving pellet feed than for those receiving mash feed. For total E. coli enumeration, caecal (P < 0.01) and colon (P < 0.01) yccT gene copies were higher for pigs receiving pellet rather than mash feed. No effect of particle size on fatty acid concentrations or on E. coli numbers was observed. Virulence gene quantification revealed no trend. Taken together, results showed that mash feed is associated with lower growth performance but with favorable intestinal changes linked to VFA levels and E. coli reduction in the intestine

Global Salmonella control in an integrated swine production system

Salmonellosis is a threat to the whole pork production chain. Different risks factors have been associated with Salmonella contamination. The aim of this project was to assess the efficacy of a comprehensive control program in a 30 000 sows integrated company located in Canada, with an emphasis on pre-harvest control measures, to limit Salmonella pork carcasses contamination. Based on previous molecular epidemiology investigations, the main sources of contamination were identified as the environment and the replacement gilts. The features of this 10 years program consisted of : Sourcing with negative replacement gilts, use of mash coarse feed on gilt finishers and sow herds, application of detailed cleaning and disinfection procedures on all farms, transport vehicles, slaughtering facilities and accessories, respect of all-in all-out and single source

PHIL photoinjector test line

LAL is now equiped with its own platform for photoinjectors tests and Research and Developement, named PHIL (PHotoInjectors at LAL). This facility has two main purposes: push the limits of the photoinjectors performances working on both the design and the associated technology and provide a low energy (MeV) short pulses (ps) electron beam for the interested users. Another very important goal of this machine will be to provide an opportunity to form accelerator physics students, working in a high technology environment. To achieve this goal a test line was realised equipped with an RF source, magnets and beam diagnostics. In this article we will desrcibe the PHIL beamline and its characteristics together with the description of the first two photoinjector realised in LAL and tested: the ALPHAX and the PHIN RF Guns

Spectral and spatial shaping of a laser-produced ion beam for radiation-biology experiments

International audience; The study of radiation biology on laser-based accelerators is most interesting due to the unique irradiation conditions they can produce, in terms of peak current and duration of the irradiation. In this paper we present the implementation of a beam transport system to transport and shape the proton beam generated by laser-target interaction for in vitro irradiation of biological samples. A set of four permanent magnet quadrupoles is used to transport and focus the beam, efficiently shaping the spectrum and providing a large and relatively uniform irradiation surface. Real time, absolutely calibrated, dosimetry is installed on the beam line, to enable shot-to-shot control of dose deposition in the irradiated volume. Preliminary results of cell sample irradiation are presented to validate the robustness of the full system