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Altres ajuts: acords transformatius de la UAB Instituto Nacional de Investigación y Tecnologı́a Agraria y Alimentaria PID2020-114060RR-C33-INFLUOMA Avian influenza viruses (AIVs) can affect wildlife, poultry, and humans, so a One Health perspective is needed to optimize mitigation strategies. Migratory waterfowl globally spread AIVs over long distances. Therefore, the study of AIV persistence in waterfowl staging and breeding areas is key to understanding their transmission dynamics and optimizing management strategies. Here, we used artificial streams mimicking natural conditions of waterfowl habitats in the Mediterranean climate (day/night cycles of photosynthetic active radiation and temperature, low water velocity, and similar microbiome to lowland rivers and stagnant water bodies) and then manipulated temperature and sediment presence (i.e., 10-13 °C vs. 16-18 °C, and presence vs. absence of sediments). An H1N1 low pathogenic AIV (LPAIV) strain was spiked in the streams, and water and sediment samples were collected at different time points until 14 days post-spike to quantify viral RNA and detect infectious particles. Viral RNA was detected until the end of the experiment in both water and sediment samples. In water samples, we observed a significant combined effect of temperature and sediments in viral decay, with higher viral genome loads in colder streams without sediments. In sediment samples, we didn't observe any significant effect of temperature. In contrast to prior laboratory-controlled studies that detect longer persistence times, infectious H1N1 LPAIV was isolated in water samples till 2 days post-spike, and none beyond. Infectious H1N1 LPAIV wasn't isolated from any sediment sample. Our results suggest that slow flowing freshwater surface waters may provide conditions facilitating bird-to-bird transmission for a short period when water temperature are between 10 and 18 °C, though persistence for extended periods (e.g., weeks or months) may be less likely. We hypothesize that experiments simulating real environments, like the one described here, provide a more realistic approach for assessing environmental persistence of AIVs.

An intact 1-year-old female rat (Rattus norvegicus) presented with a mass in the left axilla. Nodulectomy was subsequently performed, and biopsy results revealed a subcutaneous lymphangiosarcoma (LPS). Metronomic chemotherapy with toceranib and meloxicam was initiated. Three months later, a left axillary mass and an inguinal mass were observed. Histopathologic analysis confirmed the recurrence of a subcutaneous lymphangiosarcoma in the left axilla, and a mammary fibroadenoma in the inguinal area. The animal continued treatment with the same protocol of metronomic chemotherapy, and no tumor recurrence was observed. Lymphangiosarcoma is a rare, malignant neoplasm poorly described in animals. In the only previous report in rats, the LPS was located on the lumbosacral vertebrae. Lymphangiosarcoma should be included in the differential diagnosis of subcutaneous masses in rats.

A Siberian hamster with multiple papillomatous lesions in the skin and gastrointestinal mucosa was evaluated using multiple diagnostic tests. Tissues collected from this hamster were examined through macroscopic, microscopic, immunohistochemical, and ultrastructural techniques. These multifocal papillomas were associated with a cutaneous basal cell carcinoma, sebaceous adenomas, sebaceus epitheliomas and demodicosis. Large amphophilic intranuclear inclusions were detected in keratinocytes and epithelial cells of both cutaneous and gastrointestinal papillomas. The intranuclear inclusions were strongly positive by immunohistochemistry for a papillomavirus (PV) structural antigen. Electronic-dense hexagonal viral particles 30 nm in diameter were observed within the nuclei of keratinocytes and gastrointestinal tract epithelial cells by transmission electron microscopy. No viral DNA was detected with polymerase chain reaction specific hamster or broad range PV primers. This report describes noninduced multicentric papillomatosis involving the gastric mucosa and gastroduodenal junction, which may have been the result of a new PV-type infection.

A 2-year-old spayed female ferret ( Mustela putorius furo ) was presented with a 2-day history of ambulatory paraparesis of the hind limbs. On physical examination a mass was palpated in the cranial abdominal region, caudal to the stomach. A complete blood cell count revealed a normocytic normochromic anemia and reactive lymphocytes. A hypoechoic abdominal mass was observed during an ultrasound examination of the abdomen. An exploratory laparotomy was recommended and performed during which a pyramidal mass resembling a lobe of fatty liver tissue, plus omental torsion, was removed. The histopathologic diagnosis of the surgically removed mass was splenosis. The abdominal pain and ambulatory paraparesis resolved after surgery, which suggests that the paraparesis was due to pain. The findings in this report indicate that splenosis should be included as a differential diagnosis when a ferret presents with an abdominal mass and acute abdominal pain.

Our study of a large canine population investigated whether the development of symptomatic canine leishmaniosis revealed any predilection for sex, age, or breed. Included in the study were 390 leishmaniosis-affected dogs that had been treated at the Hospital Clinic Veterinari attached to the Universitat Autonoma de Barcelona. Of the diseased dogs, 238 were male (61%) and 152 were females (39%), whereas percentages for males and females in the overall reference population of dogs treated at this unit were 53% and 47%, respectively, (P

In the current retrospective study, Leishmania infantum-specific IgG, IgA and IgM levels were determined by ELISA in 106 untreated dogs with clinically-patent leishmaniasis (Sx) and in 171 clinically healthy dogs (Asx) from Spain to investigate the relationship between these Ig isotypes and clinical status. In addition, we studied if different Leishmania-specific humoral pattern exists between Asx dogs with and without cellular mediated immunity (CMI). Fifty-six dogs were assessed by means of lymphoproliferation assay (LPA), interferon production (IFN) and leishmanin skin test (LST), 71 dogs by means of both LPA and IFN and 44 only by LST. Both Sx and Asx dogs produced Leishmania-specific IgG, IgA and IgM antibodies, however the levels and proportion of positive dogs for each Ig isotype were significantly higher in Sx than in Asx ones (P

Canine leishmaniasis (CL) is a systemic parasitic disease with a wide variability of response to specific therapy: the majority of patients apparently improve with treatment, some of them respond but later relapse, and few of them do not respond at all. It has been demonstrated that the immune response plays a key role in the development and outcome of Leishmania infection in the dog and in the response to the treatment, although this response is not well understood. Some authors have suggested that ill dogs show a reduction in the percentage of circulating CD4+ lymphocytes and in the CD4+/CD8+ ratio, both of which normalize after treatment and clinical recovery. The present paper discusses the variation of the different lymphocyte subpopulations (CD3, CD4, CD8, CD21) of peripheral blood mononuclear cells (PBMC) in 28 dogs diagnosed with CL and submitted to conventional treatment with meglumine antimoniate (Glucantime®) for 1 month and with allopurinol (Zyloric®) for 1 year, in order to evaluate the usefulness of these parameters as indicators of the immunological condition of the ill animals and of the prognosis of their evolution during the treatment. It is concluded that circulating lymphocyte subpopulations are similar in dogs with leishmaniasis and in healthy dogs and that there is no correlation between the clinical status or response to therapy and the values of the counts of the different lymphocyte subpopulations. Therefore, the percentage of different lymphocyte subpopulations cannot be used as a parameter to predict the evolution of an individual patient in a clinical context.

Leishmania infantum infection has recently been described in horses in Europe. We report the results of a study on the immune response to L. infantum in horses living in an area endemic for leishmaniosis in NE Spain. Two ELISAs using protein A and anti-horse IgG conjugates were adapted to measure specific antibodies to L. infantum in horse sera. A lymphocyte proliferation assay (LPA) of peripheral blood mononuclear cells to L. infantum antigen was also performed to detect specific cellular immune response to Leishmania. Anti-L. infantum antibodies were detected in the serum of 16 of the horses studied (n = 112) using the protein A assay but not in the assay using the anti-horse IgG conjugate. Specific lymphocyte proliferation was observed in 20 out of 55 horses. This study shows that horses in the area studied mount specific immune responses to L. infantum, and must therefore be considered among the species exposed to the parasite in this region. The infrequency of leishmaniosis in horses suggests that the immune response in this species is effective in controlling the infection.

Cellular immune response to Leishmania plays a key role in canine leishmaniosis. However, there are few assays to evaluate this response in the dog. Here, we evaluated and compared three assays of specific cellular immune response to Leishmania infantum in dogs: the leishmanin skin test (LST), lymphocyte proliferation assay (LPA) and IFN-gamma cytopathic effect inhibition bioassay (IFNB). Fifty-six healthy dogs from an endemic area for leishmaniosis on the island of Mallorca were studied. In all, 37 dogs showed a positive LST and 32 a positive IFNB, 24 were positive for both assays. The 17 dogs positive for LPA also gave positive results for either LST or IFNB, or both. These findings indicate that although LST is the method of choice, IFNB is a complementary test. Therefore, both assays should be performed and analyzed jointly. In comparison with LST and IFNB, LPA is much less sensitive, and yields many false negative results.

Thirty-five budgerigars were infected with the Psittacid herpesvirus 1 (RSL-1 strain, ATCC) to study the pathogenesis of Pacheco's disease. Intramuscular (i.m.) and oral (p.o.) infection routes were used in 21 and 14 animals respectively. Animals were euthanized on days 1, 2, 3, 4, 6 and 8 post-inoculation (p.i.) and complete postmortem examinations and histological studies were performed. The presence of viral antigen in tissues was detected by immunohistochemical techniques using a rabbit polyclonal antibody. In the i.m.-infected birds, lesions were first detected on the third day p.i. and included necrotizing hepatitis and splenitis, both associated to the presence of viral antigen. Necrotic and inflammatory lesions as well as viral antigen were detected in many organs after the fourth day p.i. (oesophagus, crop, pancreas, kidney, adrenal gland, thyroid and parathyroid glands, thymus, ovary and feathers) proving generalization of the disease. Chronology of the infection was similar in the p.o.-infected birds. However, two main differences were observed between the groups: In the p.o. group, viral antigen was first detected in cloacal mucosa (3rd day p.i.), liver and spleen; and viral entry into target cells and dissemination to the rest of the tissues was slower in this group. In addition, detection of viral antigen in feather follicular epithelial cells and in granulosa cells of organ follicles are findings that could be of relevance to the transmission of the virus.

This report describes the immunocytochemical detection of CD3 antigen by means of a polyclonal antibody in sections of formol-fixed canine lymphoid tissue, embedded in paraffin wax. In all hybrid organs the lymphocytes in the T cell regions showed an intense immune reaction, located particularly in the cytoplasmic membrane and at the cytoplasmic border.