A humoral diagnostic test outperforms cellular tests in a farm with a latent tuberculosis outbreak caused by a new Mycobacterium tuberculosis complex spoligotype that affected sheep but not goats

Tuberculosis (TB) is a disease caused by members of the M. tuberculosis complex (MTC) that affects numerous species. M. caprae, a member of the complex which is close to M. bovis, is emerging and affects several different hosts that include goats, cattle, sheep, pigs, rabbits, wild boar, red deer, foxes and also humans. A new M. caprae spoligotype (SB2737) was isolated from an outbreak of sheep tuberculosis affecting a mixed sheep (323)-goat (29) farm in 2021. The index case was detected by the La Rioja slaughterhouse veterinary inspection. Tracing back to the farm of origin, both species were submitted to Comparative Intradermal Tuberculin Test (CITT) and M. bovis-specific antibody ELISA tests. A subsample was also examined by IFN-γ release assay (IGRA) and all positives were slaughtered and pathologically and microbiologically investigated. Only 1.2% of sheep and no goat were positive in the CITT, and 11.4% in the IGRA sheep subsample, while up to 36.8% were positive in two consecutive M. bovis-specific antibody ELISA tests. Goats had always tested negative in annual intradermal follow-up since 2013. Upon confirmation of the immunologically positive sheep at slaughter, all the remaining negative animals were killed and 29.2% of sheep were still found infected. This raised the final overall prevalence to 37.5%. Antibody ELISA was the most sensitive (81.4%) in vivo detection method still showing a 85.0% specificity relative to pathological and microbiological tuberculosis status. It was nearly 10 times more sensitive than skin test and had an 86.8% positive predictive value. Notwithstanding a possible singular pathogenesis of the new spoligotype, this outbreak adds up to previous reports suggesting that sheep tuberculosis could be huge reservoir of infection worldwide overlooked by skin test low sensitivity or simply lack of investigation. This makes it urgent to extend the use antibody tests to address the Trojan horse of hidden M. tuberculosis complex infections on bovine TB control programs.

Mitochondrial dysfunction-associated microbiota establishes a transmissible refractory response to anti-TNF therapy during ulcerative colitis

Anti-TNF therapy can induce and maintain a remission status during intestinal bowel disease. However, up to 30% of patients do not respond to this therapy by mechanisms that are unknown. Here, we show that the absence of MCJ, a natural inhibitor of the respiratory chain Complex I, induces gut microbiota changes that are critical determinants of the lack of response in a murine model of DSS-induced inflammation. First, we found that MCJ expression is restricted to macrophages in human colonic tissue. Therefore, we demonstrate by transcriptomic analysis of colon macrophages from DSS-induced mice that MCJ-deficiency is linked to the expression of genes belonging to the FcγR signaling pathway and contains an anti-TNF refractory gene signature identified in ulcerative colitis patients. The gut microbial composition changes observed upon DSS treatment in the MCJ-deficient mice revealed the increased presence of specific colitogenic members, including Ruminococcus gnavus and Oscillospira, which could be associated with the non-response to TNF inhibitors. Further, we show that the presence of a microbiota associated resistance to treatment is dominant and transmissible to responsive individuals. Collectively, our findings underscore the critical role played by macrophage mitochondrial function in the gut ecological niche that can substantially affect not only the severity of inflammation but also the ability to successfully respond to current therapies.

Mitochondrial dysfunction promotes microbial composition that negatively impacts on ulcerative colitis development and progression

Recent evidence demonstrates potential links between mitochondrial dysfunction and inflammatory bowel diseases (IBD). In addition, bidirectional interactions between the intestinal microbiota and host mitochondria may modulate intestinal inflammation. We observed previously that mice deficient in the mitochondrial protein MCJ (Methylation-controlled J protein) exhibit increased susceptibility to DSS colitis. However, it is unclear whether this phenotype is primarily driven by MCJ-/- associated gut microbiota dysbiosis or by direct effects of MCJ-deficiency. Here, we demonstrate that fecal microbiota transplantation (FMT) from MCJ-deficient into germ-free mice was sufficient to confer increased susceptibility to colitis. Therefore, an FMT experiment by cohousing was designed to alter MCJ-deficient microbiota. The phenotype resulting from complex I deficiency was reverted by FMT. In addition, we determined the protein expression pathways impacted by MCJ deficiency, providing insight into the pathophysiology of IBD. Further, we used magnetic activated cell sorting (MACS) and 16S rRNA gene sequencing to characterize taxa-specific coating of the intestinal microbiota with Immunoglobulin A (IgA-SEQ) in MCJ-deficient mice. We show that high IgA coating of fecal bacteria observed in MCJ-deficient mice play a potential role in disease progression. This study allowed us to identify potential microbial signatures in feces associated with complex I deficiency and disease progression. This research highlights the importance of finding microbial biomarkers, which might serve as predictors, permitting the stratification of ulcerative colitis (UC) patients into distinct clinical entities of the UC spectrum.

Differences in skin test reactions to official and defined antigens in guinea pigs exposed to non-tuberculous and tuberculous bacteria

The single and comparative intradermal tuberculin tests (SITT and CITT) are official in vivo tests for bovine tuberculosis (TB) diagnosis using bovine and avian purified protein derivatives (PPD-B and PPD-A). Infection with bacteria other than Mycobacterium tuberculosis complex (MTC) can result in nonspecific reactions to these tests. We evaluated the performance of the skin test with PPDs and new defined antigens in the guinea pig model. A standard dose (SD) of Rhodococcus equi, Nocardia sp., M. nonchromogenicum, M. monacense, M. intracellulare, M. avium subsp. paratuberculosis, M. avium subsp. avium, M. avium subsp. hominissuis, M. scrofulaceum, M. persicum, M. microti, M. caprae and M. bovis, and a higher dose (HD) of M. nonchromogenicum, M. monacense, M. intracellulare, M. avium subsp. paratuberculosis were tested using PPD-B, PPD-A, P22, ESAT-6-CFP-10-Rv3615c peptide cocktail long (PCL) and fusion protein (FP). The SD of R. equi, Nocardia sp., M. nonchromogenicum, M. monacense, M. intracellulare and M. avium subsp. paratuberculosis did not cause any reactions. The HD of M. nonchromogenicum, M. monacense, M. intracellulare, and M. avium subsp. paratuberculosis and the SD of M. avium subsp. hominissuis, M. scrofulaceum and M. persicum, caused nonspecific reactions (SIT). A CITT interpretation would have considered M. avium complex and M. scrofulaceum groups negative, but not all individuals from M. nonchromogenicum HD, M. monacense HD and M. persicum SD groups. Only animals exposed to M. bovis and M. caprae reacted to PCL and FP. These results support the advantage of complementing or replacing PPD-B to improve specificity without losing sensitivity.

Effects of Paratuberculosis Vaccination at Different Ages in a Dairy Goat Herd: A 2-Year Follow-Up

Vaccination could be considered as an effective method for paratuberculosis control, although controversial, with a need for investigation in some aspects. The objective of this study was to evaluate the effect of vaccination, depending on the age of the animals, on their immune response, the reduction of paratuberculosis cases, mortality and culled animals in a commercial dairy herd. Goats from three different ages were immunized with the inactivated Gudair^® vaccine. Peripheral antibody and IFN-γ output were evaluated for 21 months post-vaccination (mpv) and intradermal skin tests (IDSTs) for tuberculosis, with avian- and bovine-purified protein derivatives (PPD), were carried out at 6 and at 18 mpv to evaluate the humoral and cellular immune peripheral responses, respectively. The number of dead or culled animals, regardless of the reason, was also monitored and the causes of death determined by pathological examination. A significant increase in the production of IFN-γ was observed in all the vaccinated groups when the blood samples were stimulated with avian PPD, from 3 mpv to 18 mpv, and with bovine PPD, between 3 and 21 mpv. Moreover, serum antibody levels increased between 3 and 21 mpv in all vaccinated groups. The highest levels were found in animals vaccinated at 5 months, and the lowest in adult individuals. No positive reactants to tuberculosis were found by intradermal skin test. No animal losses associated with clinical paratuberculosis were detected in any of the groups. The number of total culled animals was significantly lower in the vaccinated than in the unvaccinated groups, especially on 1.5-month-old vaccinated kids. These results suggest that vaccination of paratuberculosis, especially in young animals, could induce heterologous protection.

Oral vaccination stimulates neutrophil functionality and exerts protection in a Mycobacterium avium subsp. paratuberculosis infection model

Mycobacterium avium subsp. paratuberculosis (Map) causes paratuberculosis (PTB), a granulomatous enteritis in ruminants that exerts high economic impact on the dairy industry worldwide. Current vaccines have shown to be cost-effective against Map and in some cases confer beneficial non-specific effects against other pathogens suggesting the existence of trained immunity. Although Map infection is mainly transmitted by the fecal-oral route, oral vaccination has not been deeply studied. Therefore, the aim of this study was to compare the oral route with a set of mycobacterial and non-mycobacterial vaccines with a subcutaneously administered commercially available vaccine. Training effects on polymorphonuclear neutrophils (PMNs) and homologous and heterologous in vivo protection against Map were investigated in the rabbit infection model. Oral vaccination with inactivated or live vaccines was able to activate mucosal immunity as seen by elevation of serum IgA and the expression of IL4 in peripheral blood mononuclear cells (PBMCs). In addition, peripheral PMN phagocytosis against Map was enhanced by vaccination and extracellular trap release against Map and non-related pathogens was modified by both, vaccination and Map-challenge, indicating trained immunity. Finally, PBMCs from vaccinated animals stimulated in vitro with Map antigens showed a rapid innate activation cytokine profile. In conclusion, our data show that oral vaccination against PTB can stimulate neutrophil activity and both innate and adaptive immune responses that correlate with protection.

R-COMP versus R-CHOP as first-line therapy for diffuse large B-cell lymphoma in patients ≥60 years: Results of a randomized phase 2 study from the Spanish GELTAMO group

The use of non-pegylated liposomal doxorubicin (Myocet^® ) in diffuse large B-cell lymphoma (DLBCL) has been investigated in retrospective and single-arm prospective studies. This was a prospective phase 2 trial of DLBCL patients ≥60 years old with left ventricular ejection fraction (LVEF) ≥55% randomized to standard R-CHOP or investigational R-COMP (with Myocet^® instead of conventional doxorubicin). The primary end point was to evaluate the differences in subclinical cardiotoxicity, defined as decrease in LVEF to <55% at the end of treatment. Secondary objectives were efficacy, safety, and variations of troponin and N-terminal pro-B-type natriuretic peptide (NT-proBNP) and LVEF along follow-up. Ninety patients were included, 45 in each group. No differences were observed in the percentage of patients with LVEF <55% at end of treatment (11% in R-CHOP arm vs. 7% in R-COMP arm, p = 0.697) or at 4 months (10% vs. 6%, respectively, p = 0.667) and 12 months (8% vs. 7%, respectively, p = 1). However, a higher percentage of R-CHOP compared with R-COMP patients showed increased troponin levels in cycle 6 (100% vs. 63%, p = 0.001) and at 1 month after treatment (88% vs. 56%, respectively, p = 0.015). Cardiovascular adverse events were seen in five R-CHOP patients (nine episodes, four grade ≥3) and in four R-COMP patients (five episodes, all grade 1-2). No significant differences in efficacy were observed. In conclusion, R-COMP is a feasible immunochemotherapy schedule for DLBCL patients ≥60 years, with similar efficacy to R-CHOP. However, the use of non-pegylated doxorubicin instead of conventional doxorubicin was not associated with less early cardiotoxicity, although some reduced cardiac safety signals were observed. Trial registration: ClinicalTrials.gov Identifier: NCT02012088.

Macrophages and T Lymphocytes in the Ovine Placenta After Experimental Infection With Toxoplasma gondii

Early abortion in ovine toxoplasmosis has had limited investigation. This study evaluated the immune response in the placenta of sheep orally infected with Toxoplasma gondii and euthanized between 2 and 4 weeks postinfection. Toxoplasma infection of the placenta was only found at 4 weeks after infection. Parasitic debris in foci of necrosis were immunolabeled in the maternal caruncle, whereas well-preserved intracellular parasitic vacuole-like structures were found in trophoblasts of fetal cotyledon. Early abortions had increased macrophages in caruncular septa, whereas in later abortions the placentas containing the parasite had an increase of T lymphocytes and macrophages mainly in the fetal cotyledons. This study suggests that the immune response in both the fetal and maternal compartments of the placenta may contribute to the pathogenesis of ovine toxoplasmosis and that these responses differ between early and late presentations of the disease.

Alternative Vaccination Routes against Paratuberculosis Modulate Local Immune Response and Interference with Tuberculosis Diagnosis in Laboratory Animal Models

Paratuberculosis (PTB) is an enteric granulomatous disease caused by Mycobacterium avium subsp. paratuberculosis (MAP) that mainly affects ruminants. Current vaccines have shown to be cost–effective control reagents, although they are restricted due to cross-interference with bovine tuberculosis (bTB). Therefore, novel vaccination strategies are needed and this study is focused on evaluating alternative vaccination routes and their effect on the local immune response. The MAP oral challenge rabbit model was used to evaluate and compare an experimental inactivated MAP vaccine through oral (VOR) and intradermal (VID) routes. The VID group presented the highest proportion of animals with no visible lesions and the lowest proportion of animals with MAP positive tissues. Immunohistochemistry analysis revealed that the VID group presented a dominantly M1 polarized response indicating an ability to control MAP infection. In general, all vaccinated groups showed lower calprotectin levels compared to the non-vaccinated challenged group suggesting less active granulomatous lesions. The VID group showed some degree of skin test reactivity, whereas the same vaccine through oral administration was completely negative. These data show that PTB vaccination has an effect on macrophage polarization and that the route influences infection outcome and can also have an impact on bTB diagnosis. Future evaluation of new immunological products against mycobacterial diseases should consider assaying different vaccination routes.

Tuberculosis outbreak caused by Mycobacterium caprae in a rabbit farm in Spain

Animal tuberculosis remains a great source of socioeconomic and health concern worldwide. Its main causative agents, Mycobacterium bovis and Mycobacterium caprae, have been isolated from many different domestic and wild animals. Naturally, occurring tuberculosis is extremely rare in rabbits, and implication of M. caprae has never been reported earlier. This study describes a severe tuberculosis outbreak caused by M. caprae in a Spanish farm of rabbits raised for meat for human consumption. The disease was first identified in a cachectic dam, and then it was confirmed in ten does with similar clinical signs. Subsequently, a depopulation operation was ordered for public health, animal welfare and environmental reasons. To broaden knowledge of spontaneous tuberculosis in rabbits, a study focused on pathological, epidemiological and diagnostic aspects was carried out on 51 does and 16 kittens after receiving the necessary authorizations. These animals were subjected to a modified intradermal test. After being euthanized, rabbits were examined for the presence of visible tuberculosis-compatible lesions. Lung, kidney, caecal appendix and sacculus rotundus samples underwent microbiological and anatomopathological analysis. Infection was revealed by at least one of the methods used in 71% of dams and in 44% of kittens. The intradermal test was shown to be a good indicator of infection. Lung was the tissue for which more animals were positive but renal and intestinal tissues were also affected in many cases. Apparently, M. caprae spread mainly through the aerogenous route. Infection was pathologically characterized by the absence of evident fibrous capsules surrounding granulomas. A spoligotype (SB0415) frequently found in this area was considered responsible for the outbreak but the source could not be established. Regardless of the exceptional nature of animal tuberculosis in this host, rabbit industry might not escape from its effects and therefore, current biosafety and surveillance strategies should also consider this disease.

Peripheral and placental immune responses in sheep after experimental infection with Toxoplasma gondii at the three terms of gestation

Although it is known that gestation could influence the clinical course of ovine toxoplasmosis, the precise effect of the term of gestation when sheep are infected are yet mostly unknown. The aim of this study was to evaluate the peripheral and placental immune responses developed in pregnant sheep after experimental infection with Toxoplasma gondii at different times of gestation. Thirty-six pregnant sheep were allocated in different groups, orally inoculated with sporulated oocysts of T. gondii at early, mid and late gestation and culled within 30 days post-infection. The peripheral humoral and cytokine responses were evaluated, as well as the transcription of cytokines at the placenta. Serological analysis revealed that, regardless the term of gestation when infected, specific IgG against T. gondii were detected from day 8 post-infection and there was an early peripheral release of IFN-γ at the first week post-infection followed by a short peak of IL10 and TNF-α at the second week post-infection. There were no significant differences in this response between infected groups. At the placenta, a similar increase in transcription of IFN-γ, and TNF-α was found at the three terms of gestation, while IL-4 increased mainly at the first and second terms and IL-10 transcription was higher at the last term. While these findings show that both Th1 and Th2 cytokines play a key role in the pathogenesis of ovine toxoplasmosis and that placental and peripheral immune responses do not closely correlate, there seems to be no clear modulation of these responses along the gestation.

Different lesion distribution in calves orally or intratracheally challenged with Mycobacterium bovis: implications for diagnosis

Animal tuberculosis (TB) remains a major problem in some countries despite the existence of control programmes focused mainly on cattle. In this species, aerogenous transmission is accepted as the most frequent infection route, affecting mainly the respiratory system. Under the hypothesis that the oral route could be playing a more relevant role in transmission, diagnosis and disease persistence than previously thought, this study was performed to assess the course of TB infection in cattle and its effects on diagnosis depending on the route of entry of Mycobacterium bovis. Two groups of five calves each were either endotracheally (EC) or orally (OC) challenged. Necropsies were carried out 12 weeks after challenge except for three OC calves slaughtered 8 weeks later. All animals reacted to the tuberculin skin test and the entire EC group was positive to the interferon-gamma release assay (IGRA) 2 weeks after challenge and thereafter. The first positive IGRA results for OC calves (3/5) were recorded 4 weeks after challenge. Group comparison revealed significant differences in lesion and positive culture location and scoring. TB-compatible gross lesions and positive cultures were more frequently found in the thorax (p < 0.001) and lung (p < 0.05) of EC animals, whereas OC animals presented lesions (p = 0.23) and positive cultures (p < 0.05) mainly located in the abdomen. These results indicate that the infection route seems to be a determining factor for both the distribution and the time needed for the development of visible lesions. Our study suggests that confirmation of TB infection in some skin reactor animals can be problematic if current post-mortem examination and diagnostics are not improved.

Protein stabilization by RSUME accounts for PTTG pituitary tumor abundance and oncogenicity

Increased levels of the proto-oncogene pituitary tumor-transforming gene 1 (PTTG) have been repeatedly reported in several human solid tumors, especially in endocrine-related tumors such as pituitary adenomas. Securin PTTG has a critical role in pituitary tumorigenesis. However, the cause of upregulation has not been found yet, despite analyses made at the gene, promoter and mRNA level that show that no mutations, epigenetic modifications or other mechanisms that deregulate its expression may explain its overexpression and action as an oncogene. We describe that high PTTG protein levels are induced by the RWD-containing sumoylation enhancer (RWDD3 or RSUME), a protein originally identified in the same pituitary tumor cell line in which PTTG was also cloned. We demonstrate that PTTG and RSUME have a positive expression correlation in human pituitary adenomas. RSUME increases PTTG protein in pituitary tumor cell lines, prolongs the half-life of PTTG protein and regulates the PTTG induction by estradiol. As a consequence, RSUME enhances PTTG transcription factor and securin activities. PTTG hyperactivity on the cell cycle resulted in recurrent and unequal divisions without cytokinesis, and the consequential appearance of aneuploidies and multinucleated cells in the tumor. RSUME knockdown diminishes securin PTTG and reduces its tumorigenic potential in a xenograft mouse model. Taken together, our findings show that PTTG high protein steady state levels account for PTTG tumor abundance and demonstrate a critical role of RSUME in this process in pituitary tumor cells.

Macrophage Subsets Within Granulomatous Intestinal Lesions in Bovine Paratuberculosis

Animals infected with Mycobacterium avium subspecies paratuberculosis show a variety of granulomatous lesions that range from focal forms, seen in the subclinical stages, to diffuse lesions associated with clinical signs. The aim of this study was to phenotypically characterize the macrophages present in the different lesion types using immunohistochemical methods. Lesions from a total of 23 animals with bovine paratuberculosis, natural and experimental, were examined by immunohistochemistry. Antibodies against inducible nitric oxide synthase (iNOS), tumor necrosis factor α (TNF-α), CD163, interleukin 10 (IL-10), transforming growth factor β (TGF-β), major histocompatibility complex (MHC) class II, natural resistance-associated macrophage protein 1 (Nramp-1), calprotectin, Ki-67, CD68, lysozyme, and ionized calcium-binding adaptor molecule 1 (Iba-1) molecules were employed. Samples were scored semiquantitatively using a complete histological score (H-score), reflecting the staining intensity and the percentage of immunolabeled macrophages. Differences in the H-score were seen depending on the lesion type. In focal lesions, with none or few acid-fast bacilli (AFB), macrophages were polarized toward M1 phenotype, with high H-scores for iNOS and TNF-α. Diffuse multibacillary lesions showed M2 differentiation, with high expression of CD163, IL-10, and TGF-β as well as Nramp-1 and MHC class II antigens. Macrophages in diffuse paucibacillary forms showed high H-scores for iNOS but low ones for TNF-α. Diffuse lesions, either multibacillary or paucibacillary, showed high calprotectin and low Ki-67 expression, suggesting a progressive character, while focal forms, with low H-scores for these antigens, would be consistent with latency. Lysozyme and CD68 expression were related to the amount of AFB. H-score for Iba-1 antibody was similar among all types. The findings of this study provide insights into the polarization status of macrophages and lesion development in bovine paratuberculosis.

Ruminal Leiomyosarcoma in an adult cow

An ulcerated and pedunculated intraluminal yellowish solitary mass was observed protruding into the ruminal lumen of an adult cow during an abattoir survey. Histologically, the neoplasm invaded the lamina propria-submucosa, eroded the ruminal epithelium and segmentally effaced the inner tunica muscularis. It was composed of pleomorphic spindle cells arranged in fascicles. Areas of hemorrhage, necrosis, microcystic changes as well as marked anisokaryosis, the presence of giant cells and scattered mitosis with atypical figures, were also observed. Immunohistochemically this tumor labeled positive for alpha smooth muscle actin, desmin and vimentin. With all the above findings, a diagnosis of ruminal leiomyosarcoma was confirmed. To the authors' knowledge, this is the first report of ruminal leiomyosarcoma in cattle.

Unilateral Orchitis and Epididymitis Caused by Salmonella Enterica Subspecies Diarizonae Infection in a Ram

A case of unilateral suppurative epididymo-orchitis associated with Salmonella enterica subsp. diarizonae serovar 61:k:1,5,(7) infection is described in a 2-year-old ram. Gross lesions were characterized by severe enlargement of the scrotal contents, fibrous adhesions between testicular layers, coexistence of epididymal abscesses and foci of fibrinous exudate, and testicular atrophy. Microscopically, testicular and epididymal microabscesses and diffuse inflammatory infiltrates with abundant macrophages containing short Gram-negative rods were observed. Superimposed on the chronic lesions were fibrin deposits with clusters of neutrophils, as well as walled-off granulation tissue. Bacterial colonies were also identified in thrombosed spermatic cord vessels, scrotal lymph nodes, lung, and liver. S. enterica subsp. diarizonae serovar 61:k:1,5,(7) was isolated from the affected testis. To the authors' knowledge, this is the first report of infection of the testis and epididymis by Salmonella in rams. This organism must be taken into account in the differential diagnosis of ovine genital infections.

Experimental ovine toxoplasmosis: influence of the gestational stage on the clinical course, lesion development and parasite distribution

The relation between gestational age and foetal death risk in ovine toxoplasmosis is already known, but the mechanisms involved are not yet clear. In order to study how the stage of gestation influences these mechanisms, pregnant sheep of the same age and genetic background were orally dosed with 50 oocysts of Toxoplasma gondii (M4 isolate) at days 40 (G1), 90 (G2) and 120 (G3) of gestation. In each group, four animals were culled on the second, third and fourth week post infection (pi) in order to evaluate parasite load and distribution, and lesions in target organs. Ewes from G1 showed a longer period of hyperthermia than the other groups. Abortions occurred in all groups. While in G2 they were more frequent during the acute phase of the disease, in G3 they mainly occurred after day 20 pi. After challenge, parasite and lesions in the placentas and foetuses were detected from day 19 pi in G3 while in G2 or G1 they were only detected at day 26 pi. However, after initial detection at day 19 pi, parasite burden, measured through RT-PCR, in placenta or foetus of G3 did not increase significantly and, at in the third week pi it was lower than that measured in foetal liver or placenta from G1 to G3 respectively. These results show that the period of gestation clearly influences the parasite multiplication and development of lesions in the placenta and foetus and, as a consequence, the clinical course in ovine toxoplasmosis.

Immunohistochemical study and mRNA cytokine profile of the local immune response in cattle naturally infected with Calicophoron daubneyi

In order to recognize the local immune response of the definitive host to Calicophoron daubneyi natural infection, an immunohistochemical study was carried out in the reticulum and rumen in 49 naturally infected cattle. The role of cytokines (IL-4 and IL-10 interleukins and IFN-γ) in the activation of specific defence mechanisms was evaluated by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) assays to study cytokine mRNA expression. In all infected animals, CD3+ T lymphocytes seemed to be the main element of the inflammatory infiltrate in the reticular and ruminal lamina propria at the point of the parasite adhesion. Intraepithelial globule leukocytes also showed immunolabelling for CD3. Most CD3+ cells also expressed CD4 (T cell helper) antigen although sporadic CD8+-cytotoxic lymphocytes were observed. Local expression of IFN-γ was observed in damaged papillae at the site of parasite attachment and in scattered cells in the lamina propria. B cells (CD79αcy+, CD45+ and IgG+) were found constantly in relation to lymphoid aggregates. MAC387 was expressed in squamous epithelium and in macrophages of the lamina propria of affected papillae. Macrophages in this location also stained positively for CD163 and CD68. Intraepithelial Langerhans cells and macrophages located in the lamina propria showed immunopositivity for MHCII in the affected areas. RT-qPCR analysis confirmed a statistical significant increase of IFN-γ, and IL-10 expression (p<0.01) in the rumen associated with the presence of flukes. These findings suggest a predominant Th1 polarized local immune response with the probable involvement of Th regulatory cells in cattle C. daubneyi natural infection.

Generalized severe junctional epidermolysis bullosa with congenital absence of skin in churra lambs

BACKGROUND

Up to 0.5% of churra lambs from two genetically related flocks showed congenital skin lesions of variable severity, jeopardizing the life of the lambs in the most severe cases.

HYPOTHESIS/OBJECTIVES

The primary objective of this study was to classify the type of congenital epithelial disease suffered by these animals, based on the description of the macroscopic skin defects, the histological and ultrastructural changes and the hereditary nature of the condition.

ANIMALS

Thirty affected newborn lambs from two genetically related flocks were studied. Three additional lambs acquired from two other flocks, which had no grossly apparent skin lesions and had died of infectious diseases, were studied as unaffected control animals.

METHODS

Histological and ultrastructural examinations of skin and oral mucosa samples were performed. Pedigree analyses were used to investigate genealogical relationships.

RESULTS

Generalized severe junctional epidermolysis bullosa with congenital absence of skin was described in all lambs studied and an autosomal recessive mode of inheritance was identified.

CONCLUSIONS AND CLINICAL IMPORTANCE

The pathological findings and mode of inheritance in these lambs are similar to an inherited epidermolysis bullosa subtype of humans, which has not been reported previously in veterinary medicine.

Pathological changes in cattle naturally infected by Calicophoron daubneyi adult flukes

Local host response and parasite distribution were studied in the forestomachs, abomasum, duodenum and regional lymph nodes of cattle suffering from bovine paramphistomosis. The parasites were found attached, by its ventral sucker, to small conical papillae of the rumen and reticulum. Affected papillae, showed morphological changes denoted by very narrow stalks and expanded heads. Histologically, these changes were characterized by epithelial acanthosis-hyperkeratosis of the epithelium. Infiltration of inflammatory cells was often related with the epithelial changes, although it was also found in the duodenal mucosa and submucosa. These cells were arranged as aggregates or follicles but sparse infiltration of eosinophils, globule leukocytes, mast cells or macrophages was also observed in the lamina propria. Tissue damage and inflammatory reaction were more severe in the ruminal atrium, where the largest number of flukes and affected papillae were observed. In contrast, lesions in the ruminal dorsal sac were absent or mild. Statistical correlation between lesion severity and parasite burden was confirmed.

Influence of the gestational stage on the clinical course, lesional development and parasite distribution in experimental ovine neosporosis

Neospora caninum is considered one of the main causes of abortion in cattle, yet recent studies have also emphasised its relevance as an abortifacient in small ruminants. In order to gain deeper insight into the pathogenesis of ovine neosporosis, pregnant ewes were intravenously inoculated with 10⁶ tachyzoites of the Nc-Spain7 isolate at days 40, 90 or 120 of gestation. Infection during the first term resulted in the death of all foetuses between days 19 and 21 post-infection, showing mainly necrotic lesions in foetal liver and the highest parasite DNA detection and burden in both placenta and foetal viscera. After infection at day 90, foetal death was also detected in all ewes, although later (34–48 days post-infection). In this group, lesions were mainly inflammatory. Foetal livers showed the lowest frequency of lesions, as well as the lowest parasite detection and burden. All ewes infected at day 120 delivered viable lambs, although 3 out of 9 showed weakness and recumbency. Neospora DNA was detected in all lambs but one, and parasite burden was similar to that observed in day 90 group. Lesions in this group showed more conspicuous infiltration of inflammatory cells and higher frequency in foetal brain and muscle when compared to both previous groups. These results highlight the crucial role that the stage of gestation plays on the course of ovine neosporosis, similar to that reported in bovine neosporosis, and open the doors to consider sheep as a valid model for exogenous transplacental transmission for ruminant neosporosis.

RSUME inhibits VHL and regulates its tumor suppressor function

Somatic mutations or loss of von Hippel-Lindau (pVHL) happen in the majority of VHL disease tumors, which present a constitutively active Hypoxia Inducible Factor (HIF), essential for tumor growth. Recently described mechanisms for pVHL modulation shed light on the open question of the HIF/pVHL pathway regulation. The aim of the present study was to determine the molecular mechanism by which RSUME stabilizes HIFs, by studying RSUME effect on pVHL function and to determine the role of RSUME on pVHL-related tumor progression. We determined that RSUME sumoylates and physically interacts with pVHL and negatively regulates the assembly of the complex between pVHL, Elongins and Cullins (ECV), inhibiting HIF-1 and 2α ubiquitination and degradation. We found that RSUME is expressed in human VHL tumors (renal clear-cell carcinoma (RCC), pheochromocytoma and hemangioblastoma) and by overexpressing or silencing RSUME in a pVHL-HIF-oxygen-dependent degradation stability reporter assay, we determined that RSUME is necessary for the loss of function of type 2 pVHL mutants. The functional RSUME/pVHL interaction in VHL-related tumor progression was further confirmed using a xenograft assay in nude mice. RCC clones, in which RSUME was knocked down and express either pVHL wt or type 2 mutation, have an impaired tumor growth, as well as HIF-2α, vascular endothelial growth factor A and tumor vascularization diminution. This work shows a novel mechanism for VHL tumor progression and presents a new mechanism and factor for targeting tumor-related pathologies with pVHL/HIF altered function.

Neospora caninum infection as a cause of reproductive failure in a sheep flock

Neospora caninum has been detected only sporadically in cases of ovine abortion, and it has therefore traditionally been considered as an unimportant parasite in small ruminants. This study was carried out with the aim of identifying the pathogen causing serious reproductive problems on a commercial sheep farm. Sera from all rams and ewes tested negative for antibodies against Border disease virus, Schmallenberg virus and Coxiella burnetii, and infections by these agents were therefore ruled out. Nevertheless, seropositivity to N. caninum and/or Toxoplasma gondii was detected, although the seroprevalence was higher in the case of N. caninum. The percentage of lambings and the number of lambs per dam were significantly lower in ewes that were seropositive to N. caninum while no effect on these parameters was detected in ewes that were seropositive to T. gondii. There was also no evidence of infection by T. gondii in the foetal/lamb tissues analyzed by PCR and/or immunohistopathological techniques. On the contrary, the DNA of N. caninum was detected in 13 out of 14 foetuses/lambs descendant from dams seropositive to this parasite. Characteristic lesions caused by N. caninum and/or its antigen were also detected. Genotyping of the N. caninum DNA revealed only two closely related microsatellite multilocus genotypes. The results clearly demonstrate that infection by N. caninum was the cause of the low reproductive performance of this sheep flock.

Placental thrombosis in acute phase abortions during experimental Toxoplasma gondii infection in sheep

After oral administration of ewes during mid gestation with 2000 freshly prepared sporulated oocysts of T. gondii isolate M4, abortions occurred between days 7 and 11 in 91.6% of pregnant and infected ewes. Afterwards, a further infection was carried out at late gestation in another group of sheep with 500 sporulated oocysts. Abortions happened again between days 9 and 11 post infection (pi) in 58.3% of the infected ewes. Classically, abortions in natural and experimental ovine toxoplasmosis usually occur one month after infection. Few experimental studies have reported the so-called acute phase abortions as early as 7 to 14 days after oral inoculation of oocysts, and pyrexia was proposed to be responsible for abortion, although the underline mechanism was not elucidated. In the present study, all placentas analysed from ewes suffering acute phase abortions showed infarcts and thrombosis in the caruncullar villi of the placentomes and ischemic lesions (periventricular leukomalacia) in the brain of some foetuses. The parasite was identified by PCR in samples from some placentomes of only one sheep, and no antigen was detected by immunohistochemical labelling. These findings suggest that the vascular lesions found in the placenta, and the consequent hypoxic damage to the foetus, could be associated to the occurrence of acute phase abortions. Although the pathogenesis of these lesions remains to be determined, the infectious dose or virulence of the isolate may play a role in their development.

Hereditary lissencephaly and cerebellar hypoplasia in Churra lambs

Background

Lissencephaly is a rare developmental brain disorder in veterinary and human medicine associated with defects in neuronal migration leading to a characteristic marked reduction or absence of the convolutional pattern of the cerebral hemispheres. In many human cases the disease has a genetic basis. In sheep, brain malformations, mainly cerebellar hypoplasia and forms of hydrocephalus, are frequently due to in utero viral infections. Although breed-related malformations of the brain have been described in sheep, breed-related lissencephaly has not been previously recorded in a peer reviewed publication.

Results

Here we report neuropathological findings in 42 newborn lambs from a pure Churra breed flock, with clinical signs of weakness, inability to walk, difficulty in sucking and muscular rigidity observed immediately after birth. All the lambs showed near-total agyria with only a rudimentary formation of few sulci and gyri, and a severe cerebellar hypoplasia. On coronal section, the cerebral grey matter was markedly thicker than that of age-matched unaffected lambs and the ventricular system was moderately dilated. Histologically, the normal layers of the cerebral cortex were disorganized and, using an immunohistochemical technique against neurofilaments, three layers were identified instead of the six present in normal brains. The hippocampus was also markedly disorganised and the number and size of lobules were reduced in the cerebellum. Heterotopic neurons were present in different areas of the white matter. The remainder of the brain structures appeared normal. The pathological features reported are consistent with the type LCH-b (lissencephaly with cerebellar hypoplasia group b) defined in human medicine. No involvement of pestivirus or bluetongue virus was detected by immunohistochemistry. An analysis of pedigree data was consistent with a monogenic autosomal recessive pattern inheritance.

Conclusions

The study describes the clinical and pathological findings of lissencephaly with cerebellar hypoplasia in Churra lambs for which an autosomal recessive inheritance was the most likely cause. Histopathological features observed in the cerebral cortex and hippocampus are consistent with a possible failure in neuronal migration during brain development. This report suggests that lissencephaly should be considered in the differential diagnosis of congenital neurological disease in newborn lambs showing weakness, inability to walk and difficulty sucking.

Impact of maedi-visna in intensively managed dairy sheep

Maedi-visna (MV) is a slow lentiviral disease of sheep that has a significant economic impact in many sheep-producing regions although there remains a paucity of data relating to actual production losses resulting from this disease. The objective of this study was to evaluate direct losses, through death or culling, from two dairy sheep flocks with high seroprevalences of infection over a 2 year period. Maedi-visna was found, either alone or in combination with other diseases, to be the most common disease diagnosed in these sheep, and the major cause of direct animal losses in the two flocks. Moderate to severe lesions associated with MV were found in 52% and 80% of the sheep, respectively, affecting the lungs, brain and/or mammary glands. Despite the similarity of the two flocks under study in terms of breed, number of animals, geographical proximity, and inter-change of rams, a striking difference was observed regarding the clinical presentation of the disease: in one flock the respiratory form was dominant while in the other 70% of animals died or were culled because of neurological signs.

Pathological findings in young and adult sheep following experimental infection with 2 different doses of Mycobacterium avium subspecies paratuberculosis

Mycobacterium avium subsp paratuberculosis (Map) is assumed to infect young ruminants; however, little is known concerning the possibility of adult animals becoming infected. An experimental infection was conducted to establish the effect of age and doses of Map on susceptibility to paratuberculosis in sheep. Sixteen of twenty-four 1.5-month-old Churra lambs and 23 of 30 adult ewes (from 2-11 years old) were orally challenged with an ovine field strain of Map. Thirteen ewes and 8 lambs were infected with a high dose (HD) and 10 adult sheep and 8 lambs with a low dose (LD) of Map. The remaining animals were unchallenged controls. Animals were euthanized at 110 to 120 and 210 to 220 days postinfection. Histological, bacteriological, and nested polymerase chain reaction (PCR) studies were conducted in samples of intestine and related lymphoid tissue (Peyer patches, lymph nodes). Animals were classified according to their lesions. The number of granulomas was counted in 3 tissue sections from each sample. Only the HD groups showed lesions associated with paratuberculosis (92.3% of ewes and 100% of lambs). Adults had lesions characterized by few small demarcated focal granulomas restricted to the lymphoid tissue, whereas granulomas were more numerous and larger, appearing in the lamina propria unrelated to lymphoid tissue, in the lambs. Only HD-infected lambs were positive to culture, whereas nested PCR also detected positive HD ewes and some LD animals. These results suggest that adult sheep can become infected by Map, as seen by the development of lesions, but they are focal and restricted to the lymphoid tissue.

RSUME is implicated in HIF-1-induced VEGF-A production in pituitary tumour cells

The recently cloned small RWD-domain containing protein RSUME was shown to increase protein levels of hypoxia-inducible factor-1α (HIF-1α). The latter is the oxygen-regulated subunit of HIF-1, the most important transcription factor of the cellular adaptive processes to hypoxic conditions. It is also a major regulator of vascular endothelial growth factor-A (VEGF-A), which is critically involved in the complex process of tumour neovascularisation. In this study, the expression and role of RSUME in pituitary tumours was studied. We found that RSUME mRNA was up-regulated in pituitary adenomas and significantly correlated with HIF-1α mRNA levels. Hypoxia (1% O(2)) or treatment with hypoxia-mimicking CoCl(2) enhanced RSUME and HIF-1α expression, induced translocation of HIF-1α to the nuclei and stimulated VEGF-A production both in pituitary tumour cell lines and primary human pituitary adenoma cell cultures. When RSUME expression was specifically down-regulated by siRNA, the CoCl(2)-induced increase VEGF-A secretion was strongly reduced which was shown to be a consequence of the RSUME knockdown-associated reduction of HIF-1α synthesis. Thus, RSUME plays an important role in initiating pituitary tumour neovascularisation through regulating HIF-1α levels and subsequent VEGF-A production and may therefore be critically involved in pituitary adenoma progression.

Maedi-visna: the meningoencephalitis in naturally occurring cases

Lesions were examined at different levels of the central nervous system (CNS) in 64 sheep with natural maedi-visna (MV) meningoencephalitis. All animals showed lesions in more than one of the CNS locations examined; the lesions in the cranial regions were periventricular, while those in the spinal cord affected the white matter funicles. Lesions were found particularly in the cerebellar peduncles (non-suppurative meningoencephalitis), followed by the corpus callosum, hippocampus and thoracic spinal cord. Vascular, infiltrative and malacic histopathological patterns were recognized. One pattern predominated in each section examined, although mixed forms occurred. Vascular lesions occurred with similar frequency at all CNS levels, but infiltrative and malacic lesions predominated at rostral and caudal levels, respectively. Cells consistent with macrophages and shown immunohistochemically to be associated with MV virus were seen in malacic and infiltrative lesions, at the periphery of damaged areas.

Low expression of ZHX2, but not RCBTB2 or RAN, is associated with poor outcome in multiple myeloma

RAN, ZHX2 and RCBTB2 (CHC1L) expression was evaluated by quantitative real time reverse transcription polymerase chain reaction in plasma cells from 85 monoclonal gammopathies: 58 symptomatic multiple myeloma (MM) (52 untreated, six relapsed), eight smouldering MM, five monoclonal gammopathy of undetermined significance, four plasma cell leukaemias and 10 myeloid cell lines. ZHX2 was weakly expressed in high-risk/proliferative disease compared to low-risk or indolent disease. High ZHX2 expression was associated with better response and longer survival after high-dose therapy. RCBTB2 expression was weaker in hyperdiploid versus non-hyperdiploid cases while RAN was more expressed in symptomatic MM and cell lines.

Expression of transforming growth factor-beta 1 (TGF-beta1) in different types of granulomatous lesions in bovine and ovine paratuberculosis

Paratuberculosis, caused by Mycobacterium avium subsp. paratuberculosis (Map), is manifested by a broad spectrum of clinical and lesional presentations. We have evaluated the expression of transforming growth factor-beta1 (TGF-beta1), a cytokine known to have immunosuppressor effects, by immunohistochemistry, in different paratuberculosis lesions in the intestine and lymph nodes from 20 sheep and 25 cattle. Peripheral immune responses were assessed by interferon-gamma (IFN-gamma) test and the presence of antibodies. Expression of TGF-beta1, observed in macrophages and giant cells forming the lesions, was closely related to the amount of Map. In focal and multifocal forms, usually positive to IFN-gamma test, bacilli were difficult to detect and TGF-beta1 expression was low or absent. Diffuse multibacillary lesions, negative to IFN-gamma, show large numbers of Map and the highest percentage of immunolabelled cells. Diffuse paucibacillary forms, positive to IFN-gamma, have low numbers of AFB and scant or no cells positive to TGF-beta1. The high expression of TGF-beta1 would be related to the inability of macrophages to limit the multiplication of Map.

Diagnosis of clinical cases of the nervous form of Maedi-Visna in 4- and 6-month-old lambs

The nervous form of Maedi-Visna (MV) infection was diagnosed in four lambs aged 4 and 6 months, belonging to three different Assaf flocks that were managed intensively for milk and meat production. The animals presented with hindleg ataxia that rapidly progressed to complete recumbency. Lesions consisted of a moderate to severe non-purulent encephalitis affecting mainly the cerebellar peduncles. MV virus was demonstrated in the damaged tissues by immunohistochemistry and polymerase chain reaction. The investigation demonstrated that the clinical presentation of the nervous form of MV which is reported to occur in adult sheep can also be observed in young animals.

Effects of fixative type and fixation time on the detection of Maedi Visna virus by PCR and immunohistochemistry in paraffin-embedded ovine lung samples

In doubtful cases, the histopathological diagnosis of lesions induced by Maedi Visna virus (MVV), a chronic multisystemic lentiviral disease of sheep, needs to be confirmed by the demonstration of MVV in the tissues. The influence of fixatives and the duration of fixation on the detection of MVV by immunohistochemistry (IHC) and PCR in paraffin-embedded tissues was assessed in lung samples with lesions in different degree, from five sheep serologically positive. Samples were fixed in 10% neutral buffered formalin (NBF), Bouin's solution (BS) and a zinc salts-based fixative (ZSF), for different periods of time between 24 h and 30 days. The three fixatives preserved the morphology of the tissues, although in ZSF-fixed samples an increase in the number of desquamated cells was seen in the alveoli. Tissues showed a similar degree of immunolabelling, irrespective of the duration of fixation using ZSF and NBF fixatives. MVV nucleic acids could be detected in samples fixed up to 14 days in NBF and 30 days in ZSF. However, in BS fixed tissues, immunostaining was weak and non-specific signals were observed after 4 days of fixation. Amplification of proviral DNA could not be obtained by PCR in these samples. IHC detected viral antigens in all sheep whereas one sheep with mild lesions was always negative by PCR.

Natural cases of visna in sheep with myelitis as the sole lesion in the central nervous system

Of 118 sheep with visna, 12 showed myelitis as the only nervous lesion. They were ovine lentivirus (OvLV)-seropositive and provirus DNA was demonstrated by LTR-PCR in all the samples with lesions. Clinically, all showed hindlimb paralysis and some were completely recumbent. Grossly, a swollen and discoloured area was identified in the white matter in 10 sheep. Microscopical changes consisted of a wedge-shaped area of non-suppurative leucomyelitis with mononuclear perivascular cuffing, demyelination and white matter degeneration. Except for two samples, grey matter was affected adjacent to severe white matter lesions. Three different microscopical patterns of lesion were identified, all having in common the presence of perivascular inflammation: the so-called vascular pattern was characterized by perivascular cuffs with minimal lesions in the adjacent neuroparenchyma; the malacic pattern, which was the commonest type, was characterized by severe white matter destruction and small numbers of macrophages; and the infiltrative pattern was characterized by a severe infiltrate of histiocytes in the parenchyma. Maedi-visna virus antigen was detected immunohistochemically only in areas with lesions, and the degree of immunolabelling was unrelated to the severity of the damage. Diagnosticians should bear in mind that a considerable number of visna cases show only spinal cord lesions. Examination of paraffin wax-embedded samples by LTR-PCR and immunohistochemistry would seem useful in confirming a histopathological diagnosis of visna from spinal cord samples.

Diagnosis of the nervous form of maedi-visna infection with a high frequency in sheep in Castilla y León, Spain

Between 1997 and March 2004, the nervous form, or visna, of maedi-visna infection was diagnosed in 71 of 1631 sheep (4.35 per cent) examined in the Castilla y León region of Spain, of which 634 had shown nervous signs. The presence of the virus was confirmed by immunohistochemistry and in some cases by pcr on frozen-thawed or paraffin-embedded tissue samples. The main clinical signs were hindleg ataxia and paresis, but blindness or nystagmus were also observed. Thirty-three of the affected sheep (46.5 per cent) were two years old or younger. The affected sheep showed variable degrees of a non-suppurative meningoencephalitis, and immunohistochemistry identified positive cells in all cases, with no relation to the intensity of the inflammatory lesion.

Giant Cell Tumour of Bone in a Cat with Extraskeletal Metastases: Pathological and Immunohistochemical Study

A case of giant cell tumour of bone (GCTb) in the lung and in a subcutaneous mass located in the right flank, with a probable primary origin in the mid-diaphysis of the right tibia, was described in a 8-year-old female cat. Numerous multinucleated giant cells were homogeneously distributed among a population of ovoid or spindle-shaped mononuclear cells. All of them were positive for vimentin suggesting a mesenchymal origin. Spindle-shaped tumour cells resemble fibroblastic cells, showing collagen fibres in their vicinity. Ovoid mononuclear cells are similar to macrophages, with a cytoplasm rich in electron-dense lysosomes. Multinucleated giant cells appear morphologically similar to osteoclasts. These findings are supported for the positive reaction to tartrate-resistant acid phosphatase (TRAP) and lysozyme, encountered only in ovoid and multinucleated giant cells. No immunoreactivity against human oestrogen receptors was observed in the nuclei of any neoplastic cells.