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Permeability glycoprotein (P-gp) is a membrane-bound efflux pump that mediates the active transmembrane transport of a variety of substrates. Several studies in human and canine normal and neoplastic tissues indicate that P-gp is involved in resistance to chemotherapy and in the development of multidrug resistance (MDR). The purpose of this study was to evaluate P-gp expression with the monoclonal antibody C494 in common feline tumours from 88 patients not pretreated with chemotherapy. Tumours arising from tissues with intrinsic P-gp expression consistently showed positive labelling for P-gp in a cellular pattern identical to that described for the normal feline tissues. Both P-gp positive and negative tumour cells, however, were found in mammary gland tumours, lymphomas, mastocytomas and squamous cell carcinomas. Feline mammary gland tumours in particular showed strong membranous P-gp labelling, especially in areas with infiltrative growth and atypical cells, although this was not correlated with the grade of malignancy. These findings might have implications for future response to chemotherapy.

Objectives. To compare the ability of different cyclodextrin polysulphate (CDPS) derivatives to affect human articular cartilage cell metabolism in vitro. Methods. OA chondrocytes were cultured in alginate and exposed to 5 µg/ml of 2,3,6-tri-O-methyl-β-cyclodextrin (ME-CD), 2,3-di-O-methyl-6-sulphate-β-cyclodextrin (ME-CD-6-S), 2,6-di-O-methyl-3-sulphate-β-cyclodextrin (ME-CD-3-S), (2-carboxyethyl)-β-CDPS (CE-CDPS), (2-hydroxypropyl)-β-CDPS (HP-CDPS), 6-monoamino-6-monodeoxy-β-CDPS (MA-CDPS) or β-CDPS for 5 days. Effects on IL-1-driven chondrocyte extracellular matrix (ECM) metabolism were assayed by analysis of the accumulation of aggrecan in the interterritorial matrix, IL-6 secretion and qPCR. MA-CDPS, HP-CDPS, CE-CDPS and CDPS were analysed for their in vitro effect on coagulation and their ability to activate platelets in an in vitro assay to detect possible cross-reactivity with heparin-induced thrombocytopenia (HIT) antibodies. Results. The monosulphated cyclodextrins ME-CD-6-S and -3-S failed to affect aggrecan synthesis and IL-6 secretion by the OA chondrocytes. Polysulphated cyclodextrins MA-CDPS, HP-CDPS, CE-CDPS and CDPS at 5 µg/ml concentrations, on the other hand, significantly induced aggrecan production and repressed IL-6 release by the chondrocytes in culture. aPTT and PT for all derivatives were lengthened for polysaccharide concentrations >50 µg/ml. Five micrograms per millilitre of β-CDPS concentrations that significantly modulated ECM ground substance production in vitro did not affect aPTT or PT. Furthermore, CE-CDPS, in contrast to MA-CDPS, HP-CDPS and CDPS, did not significantly activate platelets, suggesting a minimal potential to induce HIT thromboembolic accidents in vivo. Conclusions. CE-CDPS is a new, structurally adjusted, sulphated β-cyclodextrin derivative with preserved chondroprotective capacity and a promising safety profile.

Plasmid DNA (pWRG7079::MOMP) expressing the major outer membrane protein of a human Chlamydia trachomatis serovar E strain was tested for the ability to induce an immune response and protect against experimental genital infection with the same serovar. The vaccine was tested in pigs, as they are genetically and physiologically related to humans and suitable for studying C. trachomatis infection of the genital system. To increase the immune response, GM-CSF, LTA and B and CpG motives were used as adjuvants. GM-CSF was administered seven days before immunization, while the other adjuvants were administered together with the vaccine. Ten pigs were randomly divided into two groups. One group received an intravaginal primo-vaccination and a booster of 500 μg pWRG7079::MOMP, while the other group received the placebo vaccine pWRG7079. All animals were challenged with 10(8) TCID(50) of C. trachomatis serovar E. Pigs immunized with the DNA vaccine showed significantly less macroscopic lesions, vaginal excretion and chlamydial replication in the genital tract, as compared to placebo-vaccinated controls. However, infection could not be completely cleared.

This paper describes two atypical cases of granulosa cell tumours (GCTs) in Belgian Blue heifers. In the first case, an 18-month-old heifer died after ovariectomy, and a granulosa-theca cell tumour was diagnosed post-mortem. The second heifer (31 months of age) was near term and was successfully treated surgically for a malignant granulosa cell tumour. Unfortunately, no further reproductive data are available, as the heifer was sold for slaughter. This is the first report describing GCTs in Belgian Blue beef cattle.

This study presents the first case report of neuritis of the cauda equina in a dog, including characterisation of the inflammatory infiltrate. The dog in question, a 6-year-old Welsh springer spaniel, was presented with flaccid tail and faecal and urinary incontinence. The histological lesions included severe mononuclear cell infiltration of the nerve roots of the cauda equina and of the lumbar nerve roots. The infiltrate was composed of large numbers of T-lymphocytes and B-lymphocytes and small numbers of macrophages. Polymerase chain reactions of brain and spinal tissues were positive for Neospora caninum.

In this study, different traits that have been associated with bacterial virulence were studied in Yersinia ruckeri. Two isolates that had been shown to cause disease and mortality in experimentally infected rainbow trout were compared with five avirulent isolates. Both virulent isolates showed high adhesion to gill and intestinal mucus of rainbow trout, whereas the majority of non-virulent strains demonstrated significantly lower adhesion. A decrease in adherence capability following bacterial treatment with sodium metaperiodate and proteolytic enzymes suggested the involvement of carbohydrates and proteins. All strains were able to adhere to and invade chinook salmon embryo cell line (CHSE-214), fathead minnow epithelial cell line (FHM) and rainbow trout liver cell line (R1). One non-virulent strain was highly adhesive and invasive in the three cell lines, whereas the virulent strains showed moderate adhesive and invasive capacity. The internalization of several isolates was inhibited by colchicine and cytochalasin-D, suggesting that microtubules and microfilaments play a role. For all strains, intracellular survival assays showed a decrease of viable bacteria in the cells 6 h after inoculation, suggesting that Y. ruckeri is not able to multiply or survive inside cultured cells. Analysis of the susceptibility to the bactericidal effect of rainbow trout serum demonstrated that virulent Y. ruckeri strains were serum resistant, whereas non-virulent strains were generally serum sensitive.

Background: The Mongolian gerbil model is often used to investigate the interactions between different gastric Helicobacter species and the gastric tissue. A preliminary screening of a gerbil population intended for use in Helicobacter suis infection studies revealed a natural yeast infection in the stomach of these animals. After identification, we have investigated the effect of the gastric yeast infection on the outcome of an experimental H. suis infection in Mongolian gerbils. Materials and methods: Yeast cells were isolated from the stomachs of Mongolian gerbils. Identification was done by Internally Transcribed rRNA Spacer 2 Region (ITS2) PCR fragment length analysis. To investigate a possible pathologic role of this yeast, Mongolian gerbils were infected experimentally with this yeast. Co-infection with the newly isolated Helicobacter suis was performed to investigate possible interactions between both micro-organisms. Results: Kazachstania heterogenica was found colonizing the stomach of Mongolian gerbils, mainly in the antrum. Few pathologic changes were seen in the stomachs of infected animals. Experimental co-infection of gerbils with this yeast and the newly isolated Helicobacter suis showed a significant increase in inflammation in animals infected with both micro-organisms compared to animals infected only with Helicobacter suis. Conclusions: Kazachstania heterogenica colonizes the stomach of Mongolian gerbils in exactly the same regions as gastric Helicobacter species. The uncontrolled presence of this yeast in the gerbil stomach can lead to an overestimation of the inflammation caused by Helicobacter in this animal model.

Permeability glycoprotein (P-gp) is a membrane-bound efflux pump that exports various substances out of the cell. Variations in P-gp expression play an important role in susceptibility to toxic substances, drug efficacy and disease risk. In the present study, the distribution of the MDR1-gene product P-gp was determined in normal tissues of domestic shorthair cats using immunohistochemistry. Two monoclonal antibodies C494 and C219 were used, recognizing a different epitope on the human P-gp molecule. A consistent positive immunolabelling was obtained. The tissue distribution and cellular locations with antibody C494 were similar to those in man and dogs; with liver, colon, adrenal cortex and brain capillaries being consistently and intensely labelled. However, the immunolabelling in the kidney was in contradiction to man and dogs. The C219 antibody seems to react with a specific form of P-gp, only expressed in feline tissues with a barrier function, i.e. endothelia of the brain, testes and ovaries, and intestinal epithelial cells in contact with the lumen.

OBJECTIVES: Xenogenic extracellular heart valve matrices have been suggested as scaffolds for tissue engineering. However, these matrices are immunogenic and stimulate an intense cell-mediated immune response and calcification. Mitigating the immunogenicity was attempted by different doses of gamma irradiation. METHODS: Mechanical properties of gamma-irradiated porcine matrices and control matrices (nonirradiated) were examined by tensile strength testing. Irradiated matrices (1, 10, 50, and 100 gray [Gy]) and control matrices were implanted subcutaneously in Wistar rats (n = 20). After 24 h, 1, 2, 3, and 4 weeks the explants were examined by light microscopy and transmission electron microscopy. Calcium (Ca) content was determined using inductively coupled plasma-mass spectrometry. Antibody reaction against porcine tissue in the rat serum was determined. RESULTS: Tensile strength increased in irradiated matrices at the expense of elasticity. Ten gray-irradiated leaflets showed minimal lymphocytic inflammatory infiltration with preservation of ultrastructure. Ca levels after 2 weeks were as follows: control (0 Gy), 388 +/- 264 microg/mg; 1 Gy, 240 +/- 95 microg/mg; 10 Gy, 188 +/- 54 microg/mg; 50 Gy, 289 +/- 94 microg/mg; 100 Gy, 651 +/- 57 microg/mg. All implants still elicit an antibody immunoglobulin G reaction. CONCLUSIONS: Exposure to 10 Gy gamma irradiation reduces lymphocytic inflammatory infiltrates and Ca levels in acellular porcine matrices with preservation of structural integrity. This could prolong the durability of these matrices.

Objective— To report the clinical signs, diagnosis, and surgical treatment of an intranasal meningoencephalocele in a dog. Study Design— Case report. Animal— Female Border collie, 5 months old. Methods— A right intranasal meningoencephalocele was identified by computed tomography and magnetic resonance imaging. Results— The lesion was approached by a modified transfrontal craniotomy. Surgical closure of the defect at the level of the cribriform plate and removal of extruded brain tissue resulted in regression of lacrimation and coincided with absence of seizuring. Treatment with phenobarbital was gradually reduced and stopped at 7 months after surgery. At 28 months the dog remained free of seizures. Conclusion— Meningoencephalocele, although rare, can cause seizures in dogs and can be treated surgically. Clinical Relevance— A transfrontal craniotomy with excision of the meningoencephalocele and closure of the defect can be an effective treatment for an intranasal meningoencephalocele in dogs.

Helicobacter (H.) suis colonizes the stomach of more than 60% of slaughter pigs and is also of zoonotic importance. Recently, this bacterium was isolated in vitro, enabling the use of pure cultures for research purposes. In this study, mice were immunized intranasally or subcutaneously with whole bacterial cell lysate of H. suis or the closely related species H. bizzozeronii and H. cynogastricus, and subsequently challenged with H. suis. Control groups consisted of non-immunized and non-challenged mice (negative control group), as well as of sham-immunized mice that were inoculated with H. suis (positive control group). Urease tests on stomach tissue samples at 7 weeks after challenge infection were negative in all negative control mice, all intranasally immunized mice except one, and in all and 3 out of 5 animals of the H. cynogastricus and H. suis subcutaneously immunized groups, respectively. H. suis DNA was detected by PCR in the stomach of all positive control animals and all subcutaneously immunized/challenged animals. All negative control animals and some intranasally immunized/challenged mice were PCR-negative. In conclusion, immunization using antigens derived from the same or closely related bacterial species suppressed gastric colonization with H. suis, but complete protection was only achieved in a minority of animals following intranasal immunization.

Aspergillosis is a major cause of mortality in captive birds and its prognosis is often poor due to treatment failure. Voriconazole is a novel triazole antifungal agent that may be useful for the treatment of this infection in birds as it has shown promise in other animal models of the disease. We examined the pharmacokinetic behaviour of voriconazole in racing pigeons (Columbia livia forma domestica). Intravenous, oral and aerosol administration were investigated in single (10 mg/kg BW PO; 10, 5, 2.5 mg/kg BW IV), multiple dose (10, 20 mg/kg BW PO q12h, q24h) and nebulization (15 min, 10 mg/ml NaCl 0.9%) experiments. Quantitative measurements of voriconazole in plasma, as well as in lung tissue, collected at several time points, were done with a validated high performance liquid chromatography method using ultraviolet detection. Designing a treatment schedule with voriconazole is complicated by dose-dependent pharmacokinetics and induction of its biotransformation. Moreover, hepatic changes were seen in the oral multiple dose regimen at 10 and 20 mg/kg BW twice a day. Taking all features into account our study suggests that the oral dosage schedules of 10 mg/kg BW twice a day or 20 mg/kg BW once a day could be most appropriate in treating pigeons with aspergillosis.

A new cultivation method was successfully applied for the in vitro isolation of a hitherto uncultured spiral Helicobacter species associated with ulceration of the non-glandular stomach and gastritis in pigs and formerly described as 'Candidatus Helicobacter suis'. Three isolates, HS1(T), HS2 and HS3, were subcultured from the stomach mucosa of three pigs after slaughter and were analysed using a polyphasic taxonomic approach. The novel isolates grew on biphasic culture plates or very moist agar bases in microaerobic conditions and exhibited urease, oxidase and catalase activities. Sequencing of the 16S rRNA gene, the 23S rRNA gene, the partial hsp60 gene and partial ureAB genes confirmed that the strains present in the gastric mucosa of pigs constituted a separate taxon, corresponding to 'Helicobacter heilmannii' type 1 strains as detected in the gastric mucosa of humans and other primates. For all genes sequenced, the highest sequence similarities were obtained with Helicobacter felis, Helicobacter bizzozeronii and Helicobacter salomonis, Helicobacter species isolated from the gastric mucosa of dogs and cats, which have also been detected in the human gastric mucosa and which are commonly referred to as 'Helicobacter heilmannii' type 2. SDS-PAGE of whole-cell proteins of strains HS1(T), HS2 and HS3 differentiated them from other Helicobacter species of gastric origin. The results of the polyphasic taxonomic analysis confirmed that the novel isolates constitute a novel taxon corresponding to 'Helicobacter heilmannii' type 1 strains from humans and to 'Candidatus H. suis' from pigs. The name Helicobacter suis sp. nov. is proposed for the novel isolates with the type strain HS1(T) (=LMG 23995(T) =DSM 19735(T)).

Objectives: To determine if there was histological correlation with ultrasonographic images of healed fractures and implant-associated tissue after fracture treatment by plate osteotomy. Methods: Eight adult dogs were included in this retrospective study. Ultrasonography (B-mode and power Doppler) and radiography were performed before plate removal. Surgical biopsies were taken of the fracture site and the tissue adjacent to the plate. These were stained with haematoxylin and eosin to assess histomorphology and bone content and immunolabelled with CD31 to assess vascularity. Results: Ultrasound and radiographic diagnoses of a healed fracture correlated with histological finding of bone healing. Ultrasonography and histology findings of vascularity were also highly correlated. The tissue surrounding the surgical implants was significantly more vascularised on both ultrasonography and histology than that at the fracture site itself. Clinical Relevance: Ultrasonography can be used to diagnose fracture healing in plated fractures. Power Doppler ultrasonography examination of fracture healing should be performed away from surgical implants to avoid false-positive results of vascularisation.

Samples from the antrum and fundus of the stomachs of 457 pigs from 22 different herds were screened for the presence of 'Candidatus Helicobacter suis' by pcr, and samples from the antrum and/or fundus of 222 of the stomachs were tested for urease activity. The prevalence of the infection was very low before weaning, increased rapidly after weaning and reached 90 per cent in the adult boars and sows. The agreement between the results obtained with the pcr test and the urease test was very good for some age groups and sampling sites, but poor for other age groups and sampling sites.

Sarcocystis hominis, one of the three species of Sarcocystis that cause muscular cysts in cattle, is a protozoan parasite that can infect the human intestinal tract. The objective of the present study was to develop a new molecular identification method capable of discriminating among the bovine Sarcocystis species and to apply this tool in combination with stereomicroscopy to determine the presence of Sarcocystis spp. in minced beef in Belgium, with special attention to Sarcocystis hominis. A PCR technique based on the 18S rRNA sequence and by sequencing of the amplicon was highly specific. Sequence analysis of PCR products from thick-walled cysts collected from minced beef in Belgium revealed that S. hominis was present in 97.4% of the samples. Because the consumption of raw minced beef is common in Belgium and certain other European countries, these findings may point to an underestimated risk to public health.

Recently, a new enterohepatic Helicobacter species, H. equorum, was isolated from faecal samples of two clinically healthy horses. At the onset of this study, nothing was known about the prevalence of this organism in horses, nor was there any information available on the possible zoonotic character of this agent. This study aimed to determine the prevalence of H. equorum in faecal samples from equine and human origin. Therefore, faecal samples of 120 healthy privately owned horses, 227 healthy riding-school horses and 239 hospitalised horses were screened for H. equorum-DNA by means of a PCR amplifying a 1074-bp fragment of the 23S rRNA gene with primers specific for H. equorum. The vast majority of the hospitalised horses were under treatment with an antimicrobial agent at the moment of sampling, while the other horses had not been treated with an antimicrobial agent in the 14 days preceding the sampling. Stool samples of 531 humans suffering from gastro-intestinal disease and 100 clinically healthy humans were likewise examined. H. equorum-DNA was demonstrated in faeces from 0.8% of the privately owned horses, 3.1% of the riding-school horses and 7.9% of the hospitalised horses. The prevalence of H. equorum was significantly higher in hospitalised than in healthy, privately owned horses (P = 0.02). H. equorum-DNA was not detected in human samples. These results indicate that the prevalence of H. equorum in horses may be influenced by the health status of the investigated horse population and/or by antimicrobial treatment. We may additionally assume that this micro-organism does not commonly infect humans.

Mycoplasma hyopneumoniae is the etiological agent of swine enzootic pneumonia, a chronic nonfatal disease affecting pigs of all ages. To obtain better insight in the mechanisms responsible for differences in virulence between highly and low virulent M. hyopneumoniae isolates, 23 caesarean-derived, colostrum-deprived piglets were randomly assigned to three groups. Groups 1 and 2 consisted of nine animals each, which were intratracheally inoculated at 1 week of age with a highly or a low virulent isolate of M. hyopneumoniae, respectively. The remaining five animals were inoculated with sterile culture medium. Animals were euthanized at 5, 10, 15 and 28 days post-inoculation (DPI). Animals inoculated with the highly virulent isolate had more neutrophils in BAL fluid at 10, 15 and 28DPI compared to the other groups. At 10 and 15DPI, animals in the highly virulent group had significantly higher concentrations of TNF-alpha in BAL fluid. IL-1beta concentration in this group was higher at 5 and 28DPI compared to the other groups. From 10DPI onwards, significantly higher titres of M. hyopneumoniae were detected in the BAL fluid of animals inoculated with the highly virulent isolate compared to animals inoculated with the low virulent isolate. Additionally, the in vitro generation time of the highly virulent M. hyopneumoniae isolate was significantly shorter than that of the low virulent isolate. The present study indicates that the difference in pathogenicity between the highly and low virulent isolates is associated with a faster in vitro growth, a higher capacity to multiply in the lungs and the induction of a more severe inflammation process by the highly virulent isolate.

International audience; AbstractThe sheep scab mite, Psoroptes ovis, is a major problem in the beef cattle industry, especially in Belgian Blue (BB) cattle. This breed is naturally more predisposed to psoroptic mange but reasons for this high susceptibility remain unknown. Different immune responses could be a potential cause; thus in this study, the cutaneous immune response and in vitro cellular immune response after antigen re-stimulation were examined in naturally infested BB. Cytokine production in the skin and in circulating re-stimulated peripheral blood mononuclear cells (PBMC) demonstrated a mixed pro-inflammatory Th2/Th17 profile, with transcription of IL-4, IL-13, IL-6 and IL-17. Strong IL-17 up-regulation in the skin of BB was associated with an influx of eosinophils and other immune cells, potentially leading towards more severe symptoms. Virtually no changes in cutaneous IFN-γ transcription were detected, while there was substantial IFN-γ up-regulation in re-stimulated PBMC from infested and uninfested animals, potentially indicating a role of this pro-inflammatory cytokine in the innate immune response. In Holstein–Friesian (HF) cattle, generally more resistant to P. ovis infection, a largely similar immunologic response was observed. Differences between HF and BB were the lack of cutaneous IL-17 response in infested HF and low transcription levels of IFN-γ and high IL-10 transcription in re-stimulated PBMC from both infested and uninfested animals. Further research is needed to identify potential cell sources and biological functions for these cytokines and to fully unravel the basis of this different breed susceptibility to P. ovis.

In a three-month period, a Belgian Blue beef herd was confronted with three unexplained mortalities in neonatal calves, characterised by the development of a marked cervical swelling. A fourth case was referred for closer examination. On clinical examination, the animal showed a diffuse cervical swelling with oedema and crepitation, depression, anorexia and muffled lung sounds. A barium contrast-enhanced radiograph showed diffusion of contrast liquid from the oesophagus into the surrounding tissues, consistent with oesophageal perforation. Postmortem examination showed a fibrino-necrotising (peri)oesophagitis, tracheitis and myositis, pyothorax, pneumomediastinum and pericardial emphysema. A perforating tear was present in the ventral oesophagus, 15 cm caudal from the larynx. The cause was an inappropriate tubing technique of the farmer and possibly the use of an oesophageal feeder with metal end-piece.

International audience; Supersonic shear wave imaging (SSI) is a noninvasive, ultrasound-based technique to quantify the mechanical properties of bulk tissues by measuring the propagation speed of shear waves (SW) induced in the tissue with an ultrasound transducer. The technique has been successfully validated in liver and breast (tumor) diagnostics and is potentially useful for the assessment of the stiffness of arteries. However, SW propagation in arteries is subjected to different wave phenomena potentially affecting the measurement accuracy. Therefore, we assessed SSI in a less complex ex vivo setup, that is, a thick-walled and rectangular slab of an excised equine aorta. Dynamic uniaxial mechanical testing was performed during the SSI measurements, to dispose of a reference material assessment. An ultrasound probe was fixed in an angle position controller with respect to the tissue to investigate the effect of arterial anisotropy on SSI results. Results indicated that SSI was able to pick up stretch-induced stiffening of the aorta. SW velocities were significantly higher along the specimen's circumferential direction than in the axial direction, consistent with the circumferential orientation of collagen fibers. Hence, we established a first step in studying SW propagation in anisotropic tissues to gain more insight into the feasibility of SSI-based measurements in arteries.

Primaten worden vaak gebruikt als diermodel in het biomedisch onderzoek wegens hun sterke overeenkomsten met de mens. Voornamelijk penseelapen (Callithrix jacchus) en resusapen (Macaca mulatta) zijn frequent gebruikte apensoorten in het wetenschappelijk onderzoek. In dit artikel wordt een systematisch overzicht gegeven van de belangrijkste botaandoeningen bij primaten. Botaandoeningen kunnen spontaan voorkomen maar ook experimenteel worden geïnduceerd in het kader van onderzoek naar humane ziekten. Een gedegen kennis van deze pathologieën is niet enkel belangrijk om preventieve of therapeutische interventies te onderbouwen bij zowel de aap als de mens, maar draagt ook bij tot een optimale keuze van het diermodel. De, voornamelijk historisch gezien, belangrijkste groep van aandoeningen die hier worden besproken zijn de metabole aandoeningen, waarbij de nadruk ligt op rachitis/osteomalacie en osteoporose. Congenitale aandoeningen, ontwikkelingsstoornissen, intoxicaties en deficiënties met effect op het skelet worden ook besproken. Tenslotte zijn er nog de bottumoren, die weliswaar minder frequent gerapporteerd worden, maar die toch een niet te verwaarlozen groep vormen.

In trawl fisheries, beam trawls with tickler chains, chain mats or bobbin ropes are used to target flatfish or shrimp. High fuel consumption, seabed disturbance and high discard rates are well-known disadvantages of this fishing technique. These shortcomings are increasingly gaining international public and political attention, especially with the upcoming discard ban in Europe. The most promising alternative fishing technique meeting both the fisherman's aspirations, and the need for ecological progress is pulse fishing with electrotrawls. Here, the mechanical stimulation by tickler chains or bobbins is replaced by electrical stimulation resulting in reduced bottom contact, fuel costs and discards. Although a significant amount of research has been done on electrotrawls and their impact on marine organisms, most data were published in very diverse sources ranging from local non-peer-reviewed reports with a limited distribution to highly consulted international peer-reviewed journals. Therefore, there is a clear need for a comprehensive yet concise and critical overview, covering and summarizing all these data and making these available for the scientific community. This article aims to meet the above goals by discussing the working principle of electric fields, the history of electrotrawls and their current application in the North Sea and impact on marine organisms. It is concluded by elaborating on the opportunities and challenges for the further implementation of this alternative fishing technique.

'Candidatus Helicobacter suis' is a spiral-shaped bacterium that colonizes the stomach of more than 60% of slaughter pigs. The role of 'Candidatus Helicobacter suis' in gastric disease of pigs is still unclear. Experimental studies in pigs are lacking because this bacterium is unculturable until now. An inoculation protocol using 'Candidatus Helicobacter suis' infected mouse stomach homogenate was used to reproduce the infection in pigs. Control animals were inoculated using negative mouse stomach homogenate. Pigs were inoculated three times with one-week intervals and euthanized 6 weeks post inoculation. Tissue samples were taken from different mucosal stomach regions to detect 'Candidatus Helicobacter suis' by PCR and urease test. Mucosal inflammation was evaluated on formalin-fixed tissue samples. Lesions in the pars oesophagea were scored macroscopically. Infection was successful in all challenged animals, with the antrum and the fundus being predominantly positive. Infection was associated with infiltration of lymphocytes and plasma cells in the antral mucosa, evolving to follicular gastritis. No apparent inflammation of the fundic stomach region was detected in the infected animals. A clear link between 'Candidatus Helicobacter suis' and pars oesophageal lesions could not be found.

The clinical efficacy of drinking-water administration of enrofloxacin for 3 and 5 days, amoxicillin for 5 days and florfenicol for 5 days for the treatment of respiratory disease induced by an experimental Ornithobacterium rhinotracheale infection in turkeys pre-infected with avian pneumovirus (APV) was assessed based on clinical, bacteriological and histopathological examinations. Experimental groups of 15 susceptible 3-week-old turkeys were each inoculated oculonasally with APV subtype A and 3 days later with susceptible O. rhinotracheale bacteria. Antimicrobial treatment started 1 day after O. rhinotracheale inoculation. After infection, the birds were examined and scored for clinical signs, swabbed daily and weighed at different times. Five birds were euthanized and examined for macroscopic lesions at necropsy at 5 days post bacterial inoculation, and the remainder at 15 days post bacterial inoculation. Samples of the turbinates, trachea, lungs, air sacs, heart and pericardium were collected for bacteriological and/or histological examination. Recovery from respiratory disease caused by an APV/O. rhinotracheale dual infection was most successful after enrofloxacin treatment, irrespective of treatment duration, followed by florfenicol. Amoxicillin treatment was not efficacious. Clinical signs and the number of O. rhinotracheale organisms re-isolated from the trachea and the different respiratory organs were significantly reduced by enrofloxacin treatment for 3 and 5 days. O. rhinotracheale bacteria were not re-isolated from the tracheas of the birds treated with enrofloxacin except for one bird in the 5-day group, as early as 1 day after medication onset. In the group treated with enrofloxacin for 5 days, O. rhinotracheale organisms with a higher minimal inhibitory concentration value (x8) were isolated starting 2 days following treatment onset, initially from a single turkey and subsequently from the other animals.

Reasons for performing study: Endomyocardial biopsies could be a valuable tool in equine cardiology for diagnosing myocardial disease, which is probably underdiagnosed in horses because of lack of specific diagnostic measures and limitations of currently available diagnostic methods. Objectives: To describe a technique for serial right atrial and right ventricular endomyocardial biopsy in standing horses using a percutaneous approach through the jugular vein. Study design: Prospective study. Methods: Biopsy was performed in 10 healthy standing horses sedated with detomidine, under continuous electrocardiography monitoring. A 10cm (n=6), 45cm (n=1) or 98cm (n=3) introducer sheath was inserted into the right jugular vein. Under echocardiographic guidance, a biopsy forceps was introduced through the sheath into the right ventricle and right atrium and endomyocardial biopsies were acquired. Results: In all horses, 3 right ventricular biopsies were obtained from the right ventricular apex and 3 right atrial biopsies were obtained from the dorsal right atrial wall near the tuberculum intervenosum. The presence of myocardial tissue was confirmed by histology. All horses showed atrial and ventricular premature depolarisations associated with acquisition of the biopsies. In 9 horses, the arrhythmia disappeared after retraction of the forceps and introducer sheath. In one horse, ventricular premature depolarisations disappeared only after 8h. No other complications were observed. Conclusions: Endomyocardial biopsy of the right atrium and right ventricle could be performed in standing horses using a percutaneous approach through the jugular vein and was not associated with complications other than temporary arrhythmias. This technique may be useful for research purposes or as a diagnostic tool, although further research is needed to establish the safety of the technique in clinical patients with myocardial disease.

Challenge models generating gill lesions typical for columnaris disease were developed for the fry of both Common Carp Cyprinus carpio and Rainbow Trout Oncorhynchus mykiss by means of an immersion challenge and Flavobacterium columnare field isolates were characterized regarding virulence. Carp inoculated with highly virulent isolates revealed diffuse, whitish discoloration of the gills affecting all arches, while in trout mostly unilateral focal lesions, which were restricted to the first two gill arches, occurred. Light microscopic examination of the gills of carp exposed to highly virulent isolates revealed a diffuse loss of branchial structures and desquamation and necrosis of gill epithelium with fusion of filaments and lamellae. In severe cases, large parts of the filaments were replaced with necrotic debris entangled with massive clusters of F. columnare bacterial cells enwrapped in an eosinophilic matrix. In trout, histopathologic lesions were similar but less extensive and much more focal, and well delineated from apparently healthy tissue. Scanning and transmission electron microscopic observations of the affected gills showed long, slender bacterial cells contained in an extracellular matrix and in close contact with the destructed gill tissue. This is the first study to reveal gill lesions typical for columnaris disease at macroscopic, light microscopic, and ultrastructural levels in both Common Carp and Rainbow Trout following a challenge with F. columnare. The results provide a basis for research opportunities to examine pathogen-gill interactions.

The purpose of this study was to assess the possible synergism between Ornithobacterium rhinotracheale (ORT) and avian pneumovirus (APV), inoculated into turkeys via the natural route, for the reproduction of respiratory disease. Three-week-old specific pathogen free turkeys were inoculated oculonasally with either APV subtype A, ORT or both agents using two different time intervals (3 and 5 days) between APV and ORT. The birds were observed clinically on a daily basis and swabbed intratracheally at short, regular intervals. They were killed at 1, 3, 5, 8 and 15 days post single or dual inoculation and examined for gross lesions at necropsy. Samples of the turbinates, trachea, lungs, air sacs, heart, pericardium and liver were taken for bacteriological and/or histological examination. Combined APV/ORT infections resulted in overt clinical signs and a longer persistence of ORT in the respiratory tract and aggravated the macroscopic and histological lesions in comparison with the groups given single infections. In all ORT-challenged turkeys, ORT was isolated from the turbinates, trachea and lungs, but in turkeys infected with both agents ORT was frequently found in the air sacs and on a single occasion in the heart and pericardium. The time interval between APV and ORT inoculation did not have a significant effect on the outcome of the dual infection. A conspicuous important feature was the attachment of ORT to the cilia of the epithelium of the turbinates and trachea of both ORT-infected and APV/ORT-infected birds. In conclusion, the results show that ORT is able to adhere to and colonize the respiratory tract but, under the circumstances used in this study, is not capable of inducing respiratory disease without viral priming.

This paper discusses what can be expected with regard to efficacy of antibacterial vaccines used in swine, based on the present knowledge of pathogen-host interactions. First, vaccination against bacteria that mainly cause disease by production of exotoxins is considered. Vaccines containing the inactivated toxin or a non-toxic but antigenic recombinant protein derived from the exotoxin can be expected to provide protection against disease. The degree of protection induced by such vaccines varies, however, depending amongst other things on the pathogenesis of the disease. Vaccination against clostridial infections, Actinobacillus pleuropneumoniae infections, progressive atrophic rhinitis and enterotoxigenic Escherichia coli, is considered. The second part of the article deals with vaccination against extracellular bacteria. Protection against these bacteria is generally mediated by antibodies against their surface antigens and certain secreted antigens, but cellular immunity may also play a role. Efficacy of vaccines against swine erysipelas, Streptococcus suis infections, Mycoplasma hyopneumoniae infections and swine dysentery is discussed. Finally, vaccination against facultatively intracellular bacteria is considered. For protection against these bacteria cell-mediated immunity plays an important role, but antibodies may also be involved. It is generally accepted that live-attenuated vaccines are more suitable for induction of cell-mediated immunity than inactivated vaccines, although this also depends on the adjuvant used in the vaccine. As an example, vaccination against Salmonella enterica serotype Typhimurium is discussed.

This study investigated the efficacy of a single intramuscular injection of a new formulation of florfenicol to treat clinical respiratory disease following experimental Mycoplasma hyopneumoniae infection. M. hyopneumoniae-free piglets were allocated to three groups, namely, a treatment group (TG) and a positive control group (PCG), which were both inoculated endotracheally with a highly virulent isolate of M. hyopneumoniae, and a negative control group. At the onset of clinical disease, the TG received a single injection of florfenicol (30 mg/kg). All pigs were euthanased 4 weeks post-infection. Clinical symptoms were significantly reduced in the TG in comparison with the PCG. Average daily gain, feed conversion ratio, mortality and lung lesions were improved in the TG compared to the PCG, but the differences were not statistically significant.

The efficacy of two bacterins containing an Actinobacillus pleuropneumoniae serotype 10 strain was evaluated. The bacterial cells constituting bacterin 1 and 2 were grown under nicotinamide adenine dinucleotide (NAD)-rich (low-adherence capacity to alveolar epithelial cell cultures) and NAD-restricted (high-adherence capacity to alveolar epithelial cell cultures) conditions, respectively. Ten pigs were vaccinated twice with the bacterin 1 and nine pigs with the bacterin 2. Ten control animals were injected twice with a saline solution. Three weeks after the second vaccination, all pigs were endobronchially inoculated with 106.5 colony-forming units (CFU) of an A. pleuropneumoniae serotype 10 strain. In the bacterin 1 and 2 group, three and two pigs died after inoculation, respectively. Only two pigs of the control group survived challenge. Surviving pigs were killed at 7 days after challenge. The percentage of pigs with severe lung lesions (> 10% of the lung affected) was 100% in the control group, 70% in the bacterin 1 group and 22% in the bacterin 2 group. Actinobacillus pleuropneumoniae was isolated from the lungs of all animals. The mean bacterial titres of the caudal lung lobes were 7.0 x 10(6) CFU/g in the control group, 6.3 x 10(5) CFU/g in the bacterin 1 group and 1.3 x 10(6) CFU/g in the bacterin 2 group. It was concluded that both bacterins induced partial protection against severe challenge. Furthermore, there are indications that the bacterin 2, containing A. pleuropneumoniae bacteria grown under conditions resulting in high in vitro adhesin, induced better protection than the bacterin 1.

Many farrow-to-finish herds are endemically infected with Actinobacillus pleuropneumoniae. In order to control the disease efficiently, a better knowledge of the ages at which pigs become infected is necessary. Furthermore, no information is available concerning the influence of maternally derived antibodies on the colonization of the upper respiratory tract. Therefore, A. pleuropneumoniae infection patterns were studied in five farrow-to-finish pig herds (A-E) with a history of pleuropneumonia. A longitudinal study was carried out in herds A and B. In these herds, piglets from sows carrying A. pleuropneumoniae in their noses or tonsils were sampled. Nasal and tonsillar swabs as well as sera, were collected from these animals at the age of 4, 8, 12, 16 (herds A and B) and 23 weeks (herd B). At these ages other pigs from the same sows were euthanized. The lungs were macroscopically examined and samples from nose, tonsils and lungs were collected at necropsy. A cross-sectional study was performed in herds C-E. In these herds nasal and tonsillar swabs, as well as sera, were taken from 10 animals of 4, 8, 12 and 16 weeks of age. Lung, nasal and tonsillar samples were tested for the presence of A. pleuropneumoniae by routine bacteriology and PCR with mixed bacterial cultures. The sera were examined for the presence of Apx toxin neutralizing antibodies. In herd A, A. pleuropneumoniae serotype 2 and 10 strains were isolated, whereas serotype 2, 3, 5b and 8 strains were demonstrated in herd B. In most herds, A. pleuropneumoniae was detected in mixed bacterial cultures of tonsillar and/or nasal samples by PCR from the age of 4 weeks onwards. Colonization of the lungs and development of lung lesions was observed in 12- and 16-week-old animals of herd A and 23-week-old animals of herd B. In most herds, high antibody titres were detected in 4-week-old piglets. These titres decreased during the first 12 weeks of age, but thereafter, increased. It was concluded that PCR with mixed bacterial cultures from tonsillar swabs is a valuable tool for the detection of infected animals. It was also concluded that colonization of tonsils and nasal mucosae can occur in the presence of maternally derived antibodies. Infection of the upper respiratory tract without lung involvement did not result in development of Apx toxin neutralizing antibodies. Therefore, such serological assays cannot be used for the detection of subclinically infected animals.

Although Chlamydia (C.) psittaci infections are recognized as an important factor causing economic losses and impairing animal welfare in poultry production, the specific mechanisms leading to severe clinical outcomes are poorly understood. In the present study, we comparatively investigated pathology and host immune response, as well as systemic dissemination and expression of essential chlamydial genes in the course of experimental aerogeneous infection with C. psittaci and the closely related C. abortus, respectively, in specific pathogen-free chicks. Clinical signs appeared sooner and were more severe in the C. psittaci-infected group. Compared to C. abortus infection, more intense systemic dissemination of C. psittaci correlated with higher and faster infiltration of immune cells, as well as more macroscopic lesions and epithelial pathology, such as hyperplasia and erosion. In thoracic air sac tissue, mRNA expression of immunologically relevant factors, such as IFN-γ, IL-1β, IL-6, IL-17, IL-22, LITAF and iNOS was significantly stronger up-regulated in C. psittaci- than in C. abortus-infected birds between 3 and 14 days post-infection. Likewise, transcription rates of the chlamydial genes groEL, cpaf and ftsW were consistently higher in C. psittaci during the acute phase. These findings illustrate that the stronger replication of C. psittaci in its natural host also evoked a more intense immune response than in the case of C. abortus infection.

The aim of the present study was to reveal the characteristic features of genital Chlamydia suis infection and re-infection in female pigs by studying the immune response, pathological changes, replication of chlamydial bacteria in the genital tract and excretion of viable bacteria. Pigs were intravaginally infected and re-infected with C. suis strain S45, the type strain of this species. We demonstrated that S45 is pathogenic for the female urogenital tract. Chlamydia replication occurred throughout the urogenital tract, causing inflammation and pathology. Furthermore, genital infection elicited both cellular and humoral immune responses. Compared to the primo-infection of pigs with C. suis, re-infection was characterized by less severe macroscopic lesions and less chlamydial elementary bodies and inclusions in the urogenital tract. This indicates the development of a certain level of protection following the initial infection. Protective immunity against re-infection coincided with higher Chlamydia-specific IgG and IgA antibody titers in sera and vaginal secretions, higher proliferative responses of peripheral blood mononuclear cells (PBMC), higher percentages of blood B lymphocytes, monocytes and CD8+ T cells and upregulated production of IFN-γ and IL-10 by PBMC. Electronic supplementary material The online version of this article (doi:10.1186/s13567-014-0095-6) contains supplementary material, which is available to authorized users.

The use of glue as mesh fixation in laparoscopic ventral hernia repair (LVHR) significantly reduces fixation associated morbidity. This experiment evaluates the intraperitoneal use of synthetic glue as single mesh fixation.A total of 21 sheep were operated using a hernia model with two fascial defects of 2 cm(2) at the linea alba. One week later two polypropylene meshes (Dynamesh®) were implanted laparoscopically, using cyanoacrylate glue (Ifabond®) or conventional fixation (Securestrap®). In half of the animals the fascial defect was closed before mesh placement. After 1 day (n = 6), 2 weeks (n = 8) and 6 months (n = 6), a second laparoscopy was performed at which hernia recurrence, mesh integration and adhesion formation were evaluated. After euthanasia, burst strength testing and histopathology were evaluated.One animal died due to intestinal incarceration. In 20 surviving animals, no hernias were diagnosed and mesh placement was satisfying. Adhesions could hardly be observed after 1 day but were omnipresent in both groups at 2 weeks and 6 months. Burst strength testing exceeded 100 N in all samples, independent of the fixation device used. Not after 1 day, but after 2 weeks the inflammatory cell response was significantly higher in the glue group. At 6 months minor inflammation was seen, as was foreign body reaction (FBR).Using a standardized biomechanical testing system, synthetic glue can be considered an effective fixation tool in LVHR. The possible tissue toxicity of cyanoacrylates does not lead to an increased FBR. No difference in burst strength was observed for closing or not closing the defect.

Background: Mammal skin plays a pivotal role in several life preserving processes and extensive damage may therefore be life threatening. Physiological skin regeneration is achieved through ongoing somatic stem cell differentiation within the epidermis and the hair follicle. However, in severe pathological cases, such as burn wounds, chronic wounds, and ulcers, the endogenous repair mechanisms might be insufficient. For this reason, exogenous purification and multiplication of epithelial-like stem/progenitor cells (EpSCs) might be useful in the treatment of these skin diseases. However, only few reports are available on the isolation, purification and characterization of EpSCs using suspension cultures. Methods: In the present study, skin was harvested from 6 mares and EpSCs were isolated and purified. In addition to their characterization based on phenotypic and functional properties, sphere formation was assessed upon isolation, i.e. at passage 0 (P₀), and at early (P4) and late (P10) passages using different culture conditions. Results: On average 0.53 ± 0.28% of these primary skin-derived cells showed the capacity to form spheres and hence possessed stem cell properties. Moreover, significantly more spheres were observed in EpSC medium versus differentiation medium, corroborating the EpSCs' privileged ability to survive in suspension. Furthermore, the number of cells per sphere significantly increased over time as well as with subsequent passaging. Upon immunophenotyping, the presumed EpSCs were found to co-express cytokeratin (CK) 14, Casein kinase 2 beta and Major Histocompatibility Complex (MHC) I and expressed no pan CK and wide CK. Only a few cells expressed MHC II. Their differentiation towards keratinocytes (at P4 and P10) was confirmed based on co-expression of CK 14, Casein kinase 2 beta, pan CK and wide CK. In one of six isolates, a non-EpSC cell type was noticed in adherent culture. Although morphological features and immunohistochemistry (IHC) confirmed a keratinocyte phenotype, this culture could be purified by seeding the cells in suspension at ultralow clonal densities (1 and 10 cells/cm2), yet with a significantly lower sphere forming efficiency in comparison to pure EpSCs (P = 0.0012). Conclusion: The present study demonstrated sphere formation as a valuable tool to purify EpSCs upon their isolation and assessed its effectiveness at different clonal seeding densities for eliminating a cellular contamination.

Tijdens de post-mortemkeuring en het versnijden van een rund worden grijsgroene ovale spierletsels vaak als sarcosporidiosis bestempeld, terwijl de morfologische diagnose boviene eosinofiele myositis is. Deze verwarring in terminologie kan niet alleen financiële implicaties hebben, maar leidt ook tot het invoeren van incorrecte gegevens in Europese databanken. Dit artikel vat de huidige kennis samen omtrent Sarcocystis en boviene eosinofiele myositis bij het rund, als pleidooi voor een correct gebruik van de terminologie.

In deze studie werd het voorkomen van oorhematomen bij gespeende biggen onderzocht en werd nagegaan of het voorkomen gerelateerd was aan bepaalde risicofactoren. In totaal werden vijf opeenvolgende groepen biggen (n=10.657) binnen een bedrijf onderzocht vanaf het spenen (drie weken) tot het einde van de biggenbatterij (tien weken). De gemiddelde incidentie per groep bedroeg 2,3%, variërend van 1,3% tot 2,9%. Bij bargen was de incidentie 2,1%, bij zeugen 2,5% (P > 0,05). De incidentie bij biggen van eersteworpszeugen bedroeg 0,92%, bij biggen van meerdereworpszeugen was dit 2,45% (P < 0,001). De meeste nieuwe gevallen traden vier à vijf weken na het spenen op. Het risico op het ontstaan van een oorhematoom was ruim tweemaal groter langs de zijde waar een oormerk aanwezig was (RR = 2,28 [1,74 – 2,98]). Verder onderzoek, bij voorkeur op meerdere bedrijven, is wenselijk om de resultaten te bevestigen en/of te verklaren en om de controlemaatregelen te optimaliseren.