Frequent Occurrence of Simultaneous Infection with Multiple Rotaviruses in Swiss Pigs.

Rotavirus (RV) infections are the most important viral cause of diarrhea in piglets in Switzerland and are thought to cause substantial economic losses to the pig industry. However, no data are available on the occurrence and dynamics of the main porcine RV species, namely RVA, RVB, and RVC, and the diversity of the circulating strains. We therefore tested fecal samples from a cross-sectional (n = 95) and a longitudinal (n = 48) study for RVA, RVB, and RVC by real-time RT-PCR and compared the results of the cross-sectional study to postmortem findings. In addition, eight samples were fully genotyped by using next-generation sequencing. In the cross-sectional study, triple RV infections significantly correlated with diarrhea and wasting and were most frequent in the weaned age group. In the longitudinal study, the shedding of RV peaked one week after weaning and decreased thereafter. Here, mainly double infections were seen, and only a few animals showed diarrhea. The full-genome sequencing revealed a genotype pattern similar to other European countries and, importantly, co-infection by up to four RVA strains. Our results imply that the weaning of piglets may trigger not only RV shedding but facilitate co-infection of multiple RV species and strains in the same host.

Chlamydia pecorum-Induced Arthritis in Experimentally and Naturally Infected Sheep.

Chlamydia pecorum is an obligate intracellular pathogen with a wide host range including livestock such as sheep, cattle, goats, and pigs as well as wildlife species such as koalas. Chlamydial polyarthritis is an economically important disease resulting in swollen joints, lameness, stiffness, and weight loss in young sheep. In the present study, tissues from sheep experimentally or naturally infected with Chlamydia pecorum were assessed by histopathology and immunohistochemistry. Carpal, hock, and stifle joints as well as spleen, liver, kidney, lymph nodes, lung, and brain of 35 sheep from different inoculation groups were available. Two different C. pecorum strains (IPA and E58), different routes of administration (intraarticular or intravenous), UVA-irradiated IPA strain, and corresponding noninfected control groups were investigated. Similar investigations on tissues from 5 naturally infected sheep were performed. The most obvious inflammatory lesions were observed in synovial tissues and, notably, in the renal pelvis from the experimentally infected group and naturally infected animals. This resulted in chronic or chronic-active arthritis and pyelitis. Intralesional chlamydial inclusions could be demonstrated by immunohistochemistry in both tissues. Immunohistochemical evaluation of the presence and distribution of macrophages, T and B cells in synovial tissues revealed macrophages as the most prevalent inflammatory cell population. Previous observations indicated that C. pecorum isolates can infect circulating monocytes. Together with the finding of the histological lesions in synovial tissues and internal organs alongside the presence of C. pecorum DNA, these observations suggest chlamydial arthritis in lambs is the result of hematogeneous spread of C. pecorum.

Porcine Circovirus Type 2 Pathogenicity Alters Host's Central Tolerance for Propagation.

Porcine circovirus type 2 (PCV2) infections and resulting diseases are a worldwide threat to pig production. PCV2 bears a uniqueness that allows for us to understand more about chronic infections and the immune system in general. The virus can be phylogenetically subdivided into PCV2a to PCV2h genotypes. Although vaccination against PCV2 has been seen to prevent the manifestation of PCV disease, PCV2 still lingers as subclinical infections in all developmental stages of pigs. The "slow and low" tactic gives PCV2 a particular advantage in a host's immune surveillance. Since the inception of the PCV2 associated panzootic, research scientists have been trying to understand the pathogenicity of PCV2. Different research groups found that one genotype group member was more pathogenic than others. We found, in our weaner infection model with in vivo transfection of different recombinant PCV2 genotype group members that these viruses alter T cell maturation in the thymus, including host's central tolerance. Here, we extend these original observations by showing that PCV2 infected cells were also found in proximity within the female and male reproductive organs of stillborn pig fetuses. These PCV2 pools were sufficient in infecting three and half-day-old embryos in sows. Furthermore, the dominant PCV2 group member was more pathogenic in our weaner infection model. PCV2 pre-immunocompetence infection makes PCV2 recognized by central immune tolerance as belonging to the host. This also explains why pathogenicity is not a genetically intrinsic characteristic of PCV2; however, the dominance of any one PCV2 genotype group member leads to a more efficient deletion of the T cells against that specific genotype group member in the thymus.

Congenital Microphthalmic Syndrome in a Swine.

A 17-week-old crossbred finishing pig was presented for lameness of approximately one week. Clinical evaluation, including ophthalmologic examination, revealed ataxia, partial flaccid paresis of the pelvic limbs, skin lesions at feet and claws, and severely reduced vision/blindness. Both eyes had multiple persistent pupillary membranes (iris-to-iris and iris-to-lens) and hypermature cataracts. Histopathological examination of the eyes revealed microphthalmia, microphakia with cataract formation, myovascularised membrane in the vitreous, retinal detachment, and retinal dysplasia. Microscopic examination of tissues collected postmortem demonstrated nonsuppurative polioencephalomyelitis with the most prominent inflammatory lesions in the lumbar spinal cord. Subsequently, presumed Teschen/Talfan disease was confirmed by porcine teschovirus identification in the spinal cord using the reverse transcription-polymerase chain reaction (RT-PCR). To the authors' knowledge, this is the first case report describing in detail histopathological changes in the porcine congenital microphthalmic syndrome.

Clinical cystoisosporosis associated to porcine cytomegalovirus (PCMV, Suid herpesvirus 2) infection in fattening pigs.

Cystoisospora (syn. Isospora) suis is the causative agent of neonatal porcine coccidiosis and one of the main causes of diarrhoea in suckling piglets worldwide. Infection with porcine cytomegalovirus (PCMV, Suid herpesvirus 2) causes inclusion body rhinitis in pigs. In a Swiss pig herd (n=2 boars, 7 sows, 2 gilts, 18 finishing pigs, 30 fattening pigs, 54 suckling piglets), an outbreak of PCMV infection with high morbidity in all age categories, characterized by fever, anorexia, reduced general condition, respiratory signs and increased piglet mortality, was diagnosed by histopathology and molecular methods. Five fattening pigs (age~17weeks) additionally showed diarrhoea, not typical for PCMV infections, and one fattener had to be euthanized due to poor condition. Histopathologically, severe fibrinopurulent jejunoileitis with extensive atrophy and fusion of intestinal villi, loss of goblet cells and crypt abscesses associated to C. suis infection were present. In the liver, herpesvirus intranuclear inclusion bodies were observed and PCMV was confirmed by PCR/sequencing. No further infectious causes of diarrhoea (i.e. Rotavirus A; TGEV; PEDV; PCV-2; enterotoxigenic Escherichia coli or Lawsonia intracellularis) were detected in the euthanized fattener. Coproscopically, C. suis oocysts were identified in the faeces from further fatteners with diarrhoea. While C. suis usually produces disease only in suckling piglets, its association with severe intestinal lesions and diarrhoea in ~17-week-old fatteners was surprising. It is supposed that the underlying PCMV infection might have contributed to the presentation of clinical cystoisosporosis in fattening pigs. The interaction mechanisms between these two pathogens are unknown.

Occurrence, clinical involvement and zoonotic potential of endoparasites infecting Swiss pigs.

In order to estimate the diversity, clinical involvement and zoonotic potential of parasites in pigs submitted for diagnosis to the PathoPig project of the Swiss Federal Food Safety and Veterinary Office, faeces (n=125) from suckling piglets (n=39), weaners (n=60) and piglets beginning fattening (n=26) from 74 Swiss farms were examined by 3 coproscopical methods (i.e. sedimentation/zinc chloride-flotation; SAFC and Ziehl-Neelsen staining). Samples microscopically positive for Cryptosporidium were further tested by PCR/sequencing for species assessment. The most frequently detected parasite was Balantidium coli, a facultative pathogenic ciliate with zoonotic potential, in 5.1, 36.7 and 50.0% of suckling, weaners and fatteners and 43.2% of farms; however, no association with disease was observed. Isospora (syn. Cystoisospora) suis infections were detected in 13.3 and 11.1% of suckling piglets with and without diarrhoea, and in 10.0 and 13.3% of weaners and fatteners with diarrhoea, respectively, and were significant associated with emaciation. Cryptosporidium infections were detected in 10.3, 15.0 and 19.2% of sucklings, weaners and fatteners, respectively, and in 18.9% of the farms. Interestingly, two age-related species were identified: C. suis in younger piglets (2 to 6weeks) and C. scrofarum in older ones (6 to 17weeks). None of the pigs infected with C. scrofarum (n=8), but 3 of 4 piglets infected with C. suis (co-infection with I. suis in 2 cases) had diarrhoea. The zoonotic species C. parvum was not detected, nevertheless, sporadic cases of human infection with the porcine-adapted species have been reported. Ascaris suum, Trichuris suis and Strongylida were rarely detected (<4%) in all age categories.

Rumen perforation caused by horn injury in two cows.

Post-operative complications of trocarisation and rumenotomy are the most common causes of peritonitis associated with a rumen disorder. Since horn injury leading to rumen perforation has not previously been reported in the literature, two cows with this condition are reported. Small superficial skin lesions were observed in one of the cows and the other had a perforating skin lesion in the left abdomen. Both cows had signs of hypovolaemic shock. Ultrasonography revealed hypoechoic fluid, echoic lesions and occasional fibrinous septa caudoventral to the reticulum. Caudally the fluid extended to the left flank fold and occupied about one third of the peritoneal cavity. The area of the skin perforation in the left abdomen was swollen and the muscle layers could not be differentiated using ultrasonography. Diffuse fibrino-purulent peritonitis was diagnosed in both cows, and because of a poor prognosis, they were euthanased and necropsied. Perforation of the abdominal wall and rumen with diffuse fibrino-purulent peritonitis was present. Ultrasonography is a suitable tool to characterise the inflammatory lesions between the rumen and left abdominal wall and objectify the interpretation of clinical findings. Horn injury should be included in the rule outs for cattle with left abdominal skin wounds and diffuse peritonitis.

Latent porcine circovirus type 2-infected domestic pigs: A potential infection model for the effective development of vaccines against latent or chronic virus induced diseases.

Until recently, knowledge of the pathogenicity of Circoviridae and Anelloviridae family members was limited. Our previous discoveries provided clues toward resolving this issue based on studies of the latent nature of porcine circovirus type 2 (PCV2) genotype group members. We developed a conventional pig infection model that indicated that weaners already harbored latent PCV2 infection in the thymus, which enabled the viruses to specifically modulate the maturation of T-helper cells. This finding raised the possibility that the thymi of normal fetuses were already infected with PCV2. The present findings further substantiate our hypothesis that PCV2 masquerades as the host by infecting fetuses before they acquire immune-competence. We provide the first demonstration that all domestic pig fetuses preferentially harbor latent PCV2-infected cells in their thymi. These PCV2-infected cells are different from thymocytes and are located in the medulla of the fetal thymus. These latent PCV2-infected cells in fetuses are found at the same location and share characteristics with the infected cells observed in adolescent pigs. Moreover, fetuses also harbor these infected cells in other lymph system organs. We provide the first demonstration that the fetal thymus virus pools are minimally affected by sow vaccination, highlighting the immune-privileged character of this organ. Furthermore, we found a striking reduction in virus-infected cells in the fetal spleen and an increase in PCV2-infected cells in the fetal intestine of anti-PCV2-vaccinated mothers. These data indicate that specific immune response interactions occur between mothers and their progeny that are not dependent on the humoral immunity of the mother and cannot be attributed to the rudimentary humoral responses of the fetuses because these pig fetuses do not have any PCV2-specific antibodies. These shifts in our understanding of the PCV2-infected cell pool will lead to different avenues in the search for effective vaccination strategies against latent and chronic pathogens.

Molecular characterization and virus neutralization patterns of severe, non-epizootic forms of feline calicivirus infections resembling virulent systemic disease in cats in Switzerland and in Liechtenstein.

Feline calicivirus (FCV) infections are associated with oral ulceration, chronic stomatitis and a limping syndrome. Epizootic outbreaks of virulent systemic disease (VSD) have been reported in the USA and Europe. Here, the molecular characterization and neutralization patterns of FCV isolates from cases of severe, non-epizootic infection associated with skin ulceration and edema are presented. Samples from eleven symptomatic cats, four in-contact cats and 27 cats with no contact with symptomatic cats were collected and tested for FCV, feline herpesvirus-1 (FHV-1), feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV). Phylogenetic analyses based on the capsid (VP1) gene of FCV and virus neutralization with antisera raised against four FCV vaccine strains were performed. Nine kittens and two adult cats in two shelters and two veterinary clinics in four geographically distinct locations in Switzerland and Liechtenstein were affected. The cats showed fever, tongue and skin ulceration, head and paw edema, and occasionally jaundice, generalized edema and dyspnea. All symptomatic cats tested FCV-positive but were negative for FHV-1, FeLV and FIV, with the exception of one FIV-positive kitten. All kittens of one litter and both adult cats died. The disease did not spread to cats in the environment. Cats in the environment displayed phylogenetically distinct, but related, FCV strains. Virus neutralization patterns suggested that some cases might have been potentially prevented by vaccination with the optimal vaccine strain. In conclusion, clinicians should be aware of severe, non-epizootic forms of FCV infections with initial clinical presentations similar to VSD.

HISTOLOGIC, IMMUNOHISTOCHEMICAL, AND ELECTRON MICROSCOPIC CHARACTERIZATION OF A MALIGNANT IRIDOPHOROMA IN A DWARF BEARDED DRAGON (POGONA HENRYLAWSONI).

A dwarf bearded dragon (Pogona henrylawsoni) was presented with a white subcutaneous mandibular mass and multiple nodules in the oral mucosa, heart, liver, kidney, intestine, and visceral fat. Histologically, the tumor consisted of densely packed spindle-shaped cells with brow intracytoplasmic pigment that exhibited white-blue birefringence with polarized light. Immunohistochemical staining was negative for S-100 and weakly positive with melan A. Electron microscopic examination revealed cytoplasmic irregular and oblong empty spaces, laminated and often arranged into short stacks, compatible with reflecting platelet profiles typically seen in iridophores. However, in unstained ultrathin sections, electron-dense crystalline material was present, which filled the empty spaces described for stained sections before. Based on histology, immunohistochemistry, and biologic behavior, a malignant iridophoroma was diagnosed. To the authors' knowledge, iridophoromas in lizards have rarely been characterized by using electronic microscopy. Moreover, this is the first description of an iridophoroma in a dwarf bearded dragon.

T-cell reprogramming through targeted CD4-coreceptor and T-cell receptor expression on maturing thymocytes by latent Circoviridae family member porcine circovirus type 2 cell infections in the thymus.

Although porcine circovirus type 2 (PCV2)-associated diseases have been evaluated for known immune evasion strategies, the pathogenicity of these viruses remained concealed for decades. Surprisingly, the same viruses that cause panzootics in livestock are widespread in young, unaffected animals. Recently, evidence has emerged that circovirus-like viruses are also linked to complex diseases in humans, including children. We detected PCV2 genome-carrying cells in fetal pig thymi. To elucidate virus pathogenicity, we developed a new pig infection model by in vivo transfection of recombinant PCV2 and the immunosuppressant cofactor cyclosporine A. Using flow cytometry, immunofluorescence and fluorescence in situ hybridization, we found evidence that PCV2 dictates positive and negative selection of maturing T cells in the thymus. We show for the first time that PCV2-infected cells reside at the corticomedullary junction of the thymus. In diseased animals, we found polyclonal deletion of single positive cells (SPs) that may result from a loss of major histocompatibility complex class-II expression at the corticomedullary junction. The percentage of PCV2 antigen-presenting cells correlated with the degree of viremia and, in turn, the severity of the defect in thymocyte maturation. Moreover, the reversed T-cell receptor/CD4-coreceptor expression dichotomy on thymocytes at the CD4(+)CD8(interm) and CD4SP cell stage is viremia-dependent, resulting in a specific hypo-responsiveness of T-helper cells. We compare our results with the only other better-studied member of Circoviridae, chicken anemia virus. Our data show that PCV2 infection leads to thymocyte selection dysregulation, adding a valuable dimension to our understanding of virus pathogenicity.

T-cell lymphoma in the nasal cavity of a Brown Swiss heifer.

BACKGROUND: Tumours of the upper respiratory tract are relatively common in cattle, but to our knowledge, there have been no reports of lymphoma of the nasal cavity. This case report describes the findings in a 22-month-old Brown Swiss heifer with T-cell lymphoma of the nasal cavity. CASE PRESENTATION: The main clinical findings were lacrimation and swelling of the head above and below the right eye, mild exophthalmos, third eyelid prolapse, purulent ocular discharge and congestion of scleral blood vessels. An endoscope could only be introduced a few centimetres into the right nasal cavity because of an obstructing mass in the nasal passage. Radiographs showed a mass in the right nasal cavity and maxillary sinus. A tentative diagnosis of neoplasia of the right nasal cavity was made and the heifer was euthanased and necropsied. A firm, tan mass measuring 10 by 13 by 15 cm in the right half of the head occupied the entire right nasal cavity. A final diagnosis of high-grade, malignant, small-sized T-cell lymphoma was made based on histological and immunohistochemical evaluation. A distinction between αß T-cell or γδ T-cell lymphoma was not made. CONCLUSIONS: This report on T-cell lymphoma in the nasal cavity of a cow suggests that nasal lymphoma should be included in the list of differential diagnosis of conditions associated with dyspnoea and stertorous breathing in cattle.

Involvement of Toxoplasma gondii in reproductive disorders in Swiss pig farms.

To determine the role of Toxoplasma gondii in reproductive failure, 108 of 113 sows that had aborted or delivered stillborn or weak piglets from 58 Swiss farms were serologically tested for specific antibodies against T. gondii tachyzoite antigens by ELISA. Additionally, formalin-fixed and paraffin-embedded tissues from 123 foetuses or stillborn piglets derived from 25 seropositive and 27 seronegative sows were analyzed by real-time PCR for T. gondii DNA. Tissues from animals showing a positive reaction in real-time PCR were subsequently tested by immunohistochemistry for the presence of T. gondii antigens. Antibodies against T. gondii were detected in 24.1% (26 out of 108) of sows with reproductive failure, and 37.3% (22 of 58) of the 58 tested farms had seropositive sows. No significant differences in the prevalences were observed in relation to the housing system (exclusive indoor housing, indoor housing with outdoor yard and exclusive outdoor housing) neither at the individual nor at the farm levels. By real time-PCR, T. gondii DNA was detected in three placentas from one seropositive sow (abortion at 71 gestation days [gd]), and in brain tissues from one foetus (abortion at 76 gd), one stillborn (116 gd) and one mummy (112 gd) delivered by three further seropositive sows, but in no sample derived from seronegative dams. By immunohistochemical staining, the presence of T. gondii could be confirmed only in placenta samples. In one of the cases, a co-infection with porcine parvovirus (PPV) was detected. These results suggest vertical transmission of T. gondii and/or placental infection in at least 3.5% (4 of 113) of sows with reproductive disorders. Therefore, T. gondii should be more frequently included in the routine differential diagnosis of reproductive failure in sows. In addition, a proper disposal of placentas and abortion material beyond the reach of cats could help to interrupt the further dissemination of this parasite at the farm level.

Ruptured urinary bladder attributable to urethral compression by a haematoma after vertebral fracture in a bull.

BACKGROUND: In male cattle, rupture of the urinary bladder is usually associated with urethral obstruction by uroliths. Less common causes include urethral compression or stricture. This case report describes the findings in a young Limousion breeding bull with rupture of the urinary bladder because of urethral compression by a haematoma after coccygeal fracture. CASE PRESENTATION: The bull had been introduced into a 40-head Red-Holstein herd one week before being injured. One week after introduction to the herd, the bull had an acute onset of anorexia and he was referred to the clinic. There was marked abdominal distension, reduced skin turgor and enophthalmus. The serum concentration of urea and creatinine was increased. Ultrasonographic examination revealed severe ascites and abdominocentesis yielded clear yellow fluid with high urea and creatinine concentrations, which supported a diagnosis of uroperitoneum. The bull was euthanatized because of a poor prognosis. Postmortem examination revealed a comminuted fracture of the first two coccygeal vertebrae associated with a massive haematoma that obstructed entire pelvic cavity. The haematoma compressed the urethra thereby preventing outflow of urine, which resulted in a 5-cm tear ventrally at the neck of the bladder. It was assumed that the newly-introduced bull had sustained the vertebral fractures when he was mounted by a cow. CONCLUSIONS: The present case study serves to expand the differential diagnosis of urinary bladder rupture. Therefore, in addition to obstructive urolithiasis, compression and stricture of the urethra might be considered in male cattle with uroperitoneum.

Bovine besnoitiosis in Switzerland: imported cases and local transmission.

Bovine besnoitiosis is an economically important disease of cattle, caused by Besnoitia besnoiti (Protozoa, Apicomplexa). A considerable spreading of this parasitic infection has been observed in Europe in the last ten years, mainly related to animal trade. In order to investigate the possibility of B. besnoiti being unnoticed introduced and getting established in Switzerland through the import of breeding cattle from France, a total of 767 animals (650 cattle imported from France and 117 cattle that had contact with B. besnoiti positive cattle in Swiss farms) were screened for antibodies against B. besnoiti by both a commercial ELISA and by the indirect fluorescent antibody test (IFAT). A total of 101 (13.17%) samples showed a positive reaction in ELISA (cut-off: percent of positivity [PP] ≥ 15) and 16 (2.09%) samples had IFAT titers ≥ 1:100. Eight of those samples reacted positive in Western blot (WB), corresponding to five imported Limousin cattle (two cows and one bull from France and two cows from Germany) and to three cattle born in Switzerland (one Limousin heifer born from one of the positive German cows, and two adult Braunvieh cows, that had been in contact with one of the French cows at a Swiss farm). Seven of those animals were subclinically infected and one animal showed only very mild signs. They were subsequently slaughtered, and the serological diagnosis could be confirmed by real-time PCR and/or histopathology in seven animals. The most frequent parasite localizations were the tendons and surrounding connective tissue of the distal limbs and the skin of the head region. Furthermore, B. besnoiti could be successfully isolated in vitro from one French, one German and one Swiss cattle (isolates Bb-IPZ-1-CH, Bb-IPZ-2-CH and Bb-IPZ-3-CH). In the current situation in Switzerland, prophylactic and control measures should include a serological examination of cattle to be imported from endemic areas and the culling of all confirmed positive animals from the herd. The evidence of B. besnoiti infection in both imported and locally born cattle shows that the conditions for the establishment and dissemination of this parasite in Switzerland seem to be adequate.

Situs ambiguus in a Brown Swiss cow with polysplenia: case report.

BACKGROUND: Laterality defects are rare in cattle and usually manifest as asplenia or polysplenia syndrome. These syndromes may be associated with situs ambiguus, which is a dislocation of some but not all internal organs. The objective of this report was to describe the clinical and post-mortem findings including the macroscopic and microscopic anatomy of selected organs in a cow with polysplenia and situs ambiguus. CASE PRESENTATION: A 3.5-year-old Brown Swiss cow was referred to the Department of Farm Animals, Vetsuisse Faculty, University of Zurich, because of poor appetite and recurrent indigestion. A diagnosis of situs ambiguus was based on the results of physical examination, ultrasonography, exploratory laparotomy and post-mortem examination. The latter revealed that the rumen was on the right side and lacked compartmentalisation. There were two spleens, one on the left (26.5 x 12.0 cm) and one on the right (20.5 x 5.5 cm), and the omasum was located craniolateral to the ruminoreticulum on the left. The abomasum was located on the right, although it had initially been displaced to the left. The three-lobed liver occupied the left and central cranioventral aspect of the abdominal cavity (cavum abdominis). Only the right and left hepatic veins (vena hepatica dextra and sinistra) drained into the thoracic segment of the caudal vena cava (vena cava caudalis), and histological changes in the liver were indicative of impaired haemodynamics. The mesojejunum was not fused with the mesentery of the spiral loop (ansa spiralis) of the ascending colon (colon ascendens). The latter was folded and the transverse colon (colon transversum) ran caudal to the cranial mesenteric artery (arteria mesenteria cranialis). Fibrotic constrictions were seen in the lumen of the caecum and proximal loop (ansa proximalis) of the ascending colon. Both kidneys were positioned retroperitoneally in a lumbar position. The lumbar segment of the caudal vena cava did not descend to the liver and instead drained into the right azygous vein (vena azygos dextra). CONCLUSIONS: Recurrent digestive problems and poor production in this patient may have been caused by a lack of rumen compartmentalisation, abnormal abomasal motility, constrictions in the large intestine (intestinum crassum) and fibrosis of the liver. The abomasum had abnormal motility most likely because it was anchored inadequately and only at its cranial aspect to the liver by the lesser omentum (omentum minus) and to the dorsal abdominal wall and rumen by a short greater omentum (omentum majus).

Chlamydiaceae family, Parachlamydia spp., and Waddlia spp. in porcine abortion.

At present, despite extensive laboratory investigations, most cases of porcine abortion remain without an etiological diagnosis. Due to a lack of recent data on the abortigenic effect of order Chlamydiales, 286 fetuses and their placentae of 113 abortion cases (1-5 fetuses per abortion case) were investigated by polymerase chain reaction (PCR) methods for family Chlamydiaceae and selected Chlamydia-like organisms such as Parachlamydia acanthamoebae and Waddlia chondrophila. In 0.35% of the cases (1/286 fetuses), the Chlamydiaceae real-time PCR was positive. In the Chlamydiaceae-positive fetus, Chlamydia abortus was detected by a commercial microarray and 16S ribosomal RNA PCR followed by sequencing. The positive fetus had a Porcine circovirus-2 coinfection. By the Parachlamydia real-time PCR, 3.5% (10/286 fetuses of 9 abortion cases) were questionable positive (threshold cycle values: 35.0-45.0). In 2 of these 10 cases, a confirmation by Chlamydiales-specific real-time PCR was possible. All samples tested negative by the Waddlia real-time PCR. It seems unlikely that Chlamydiaceae, Parachlamydia, and Waddlia play an important role as abortigenic agents in Swiss sows.

Coreplication of the major genotype group members of porcine circovirus type 2 as a prerequisite to coevolution may explain the variable disease manifestations.

A member of the family Circoviridae, porcine circovirus type 2 (PCV2), is associated with postweaning multisystemic wasting syndrome (PMWS), a recent emerging disease worldwide. PCV2 is also found in clinically asymptomatic animals. This paradoxical finding makes the syndrome etiology challenging. We developed new assays to study PCV2 with links to syndrome etiology. For analysis, we used PCV2-infected tissues from subclinically infected and diseased piglets. We compared antigen- and PCV2 DNA-derived signals for tissue localization and intensity. Oligonucleotides were designed to the signature motif of the PCV2 capsid open reading frame to discriminate experimentally between PCV2 genotype groups by PCR, in situ hybridization (ISH), and fluorescence in situ hybridization (FISH). Unexpectedly, all PCV2-infected animals carried both PCV2a and PCV2b genotype group members. Using confocal microscopy, genotype single-cell infections and cell superinfections were visible. Additionally, we discriminated replicative DNA from total PCV2 DNA isoforms with FISH. This aided in our inquiry into cellular genotype-specific replication. Importantly, single-genotype-group replication was not observed. In infected cells with replicating virus, both genotype groups were equally present. These findings suggest PCV2 genotype group members relaxed replication regulation requirements and may even point to PCV2 replication cooperativity in vivo. These observations explain the readily seen PCV2 DNA recombinations and the high overall PCV2 genome plasticity. Hence, we suggest a novel mechanism of syndrome etiology that consists of a continuously changing PCV2 genome pool in hosts and pig herds, posing a constant challenge to the individual maturing immune system.

Ultrasonographic findings in a cow with abomasal lymphosarcoma: case report.

BACKGROUND: This case report describes the clinical and ultrasonographic findings in a Swiss Braunvieh cow with lymphosarcoma of the abomasum. CASE PRESENTATION: The main clinical findings were vomiting in response to eating and melena. The results of serum biochemistry and rumen fluid analysis were indicative of abomasal reflux syndrome. The main ultrasonographic findings were two enlarged lymph nodes caudal to the reticulum and a severely enlarged abomasum with thickening of the abomasal wall and folds. Based on all the findings, pyloric stenosis caused by lymphosarcoma was tentatively diagnosed and later confirmed at postmortem examination. CONCLUSIONS: This is an interesting case, which broadens the spectrum of abomasal reflux syndrome.