The First Case of Bovine Astrovirus-Associated Encephalitis in the Southern Hemisphere (Uruguay), Uncovers Evidence of Viral Introduction to the Americas From Europe.

Astrovirus species members of the Mamastrovirus genus (family Astroviridae) have been increasingly recognized as neuroinvasive pathogens in various mammals, including humans, mink, cattle, sheep, and pigs. While cases of astrovirus-associated encephalitis have been reported in North America, Europe, and Asia, their presence has never been documented in the Southern hemisphere. This paper describes a case of astrovirus-associated encephalitis in cattle in Uruguay that broadens the geographic distribution and genetic diversity of neuroinvasive astroviruses and provides phylogeographic evidence of viral introduction to the Americas from Europe. A 22-month-old Holstein steer from a farm in Colonia Department, Uruguay developed progressive neurological signs over a 3-days period before dying. Histopathological examination of the brain and proximal cervical spinal cord revealed disseminated, moderate to severe lymphocytic, histiocytic, and plasmacytic poliomeningoencephalomyelitis with neuronal necrosis. A Mamastrovirus strain in the CH13/NeuroS1 clade, that we called bovine astrovirus (BoAstV)-Neuro-Uy, was identified by reverse transcriptase PCR followed by nearly complete genome sequencing. Additionally, BoAstV was detected intralesionally in the brain by chromogenic RNA in situ hybridization within neuronal perikarya, axons and dendrites. Phylogenetic analysis of BoAstV-Neuro-Uy revealed a close relationship to neurotropic BoAstVs within the Virginia/Human-Mink-Ovine clade, which contains a growing cadre of neuroinvasive astroviruses. Analyzing the complete coding region of neuroinvasive BoAstVs sequences available in GenBank, we estimated an evolutionary rate of 4.27 × 10-4 (95% HPD 2.19-6.46 × 10-4) nucleotide substitutions/site/year. Phylogeographic analysis suggests that the common viral ancestor circulated in Europe between 1794-1940, and was introduced in Uruguay between 1849-1967, to later spread to North America and Japan

Perinatal mortality in cattle associated with goitre

The role of iodine in ruminant reproductive function is well known. However, studies about the impact of this deficiency in reproductive performance of cattle are scarce. This paper describes stillbirth episodes in three beef cow herds in northwest Argentina. The stillbirth losses ranged between 15.8 and 25%. Grossly, the thyroid glands presented diffuse, bilateral and symmetric enlargement. Microscopically, follicular epithelium showed severe hyperplasia and hypertrophy, forming multiple stratified layers of large cuboidal cells, with papillary projections into the follicular lumen. Free thyroxine (T4f) mean levels in serum from aborted cows and heifers was 0.63±0.05 ng/dl. A diagnosis of congenital goiter was performed based on these findings. Following the diagnosis, the herds were supplemented orally and parentally with iodine. Mean T4f level post-treatment was 0.80±0.05 ng/dl and the stillbirth rate dropped sharply.Fil: Micheloud, Juan Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentina. Universidad Católica de Salta; ArgentinaFil: Olmos, Leandro Hipolito. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentina. Universidad Católica de Salta; ArgentinaFil: García, Juan Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Mattioli, Guillermo Alberto. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Uzal, Francisco Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of California at Davis; Estados Unido

Identification of Neospora caninum in aborted bovine fetuses of Southern Chile

The aim of this study was to identify Neospora caninum in histologic sections of brain and optic nerve of aborted bovine fetuses. Sections of these tissues from 296 aborted bovine fetuses from Southern Chile, submitted between 2000 and 2010, to the Instituto de Patología Animal of the Universidad Austral de Chile were analyzed. Forty-four (14.9%) fetuses had microscopic lesions compatible with bovine neosporosis, including gliosis, necrosis, intralesional protozoan cysts and neuritis of optic nerves. N. caninum was identified by immunohistochemistry in brain sections of 27 cases (9.1%) with compatible lesions. Positive immunostaining was also found in the optic nerves of 13 cases (4.4%) with neuritis. N. caninum DNA was identified by PCR in brain sections in 31 cases (10.5%). In total, 36 cases (12.2%) were positive by either technique. Phylogenetic analysis of the ITS1 gene sequence of N. caninum revealed a high degree of conservation among different isolates. This is the first report of N. caninum-associated optic neuritis in cattle and also the first report of confirmed bovine abortion associated with this parasite in Chile.Fil: Moroni, Manuel. Universidad Austral de Chile; ChileFil: Navarro, Mauricio. Universidad Austral de Chile; ChileFil: Paredes, Enrrique. Universidad Austral de Chile; ChileFil: Romero, Alex. Universidad Austral de Chile; ChileFil: Alberdi, Aintzane. Universidad Austral de Chile; ChileFil: Lischinsky, Tania. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Moore, Dadin Prando. Instituto Nacional de Tecnología Agropecuaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Campero, Carlos Manuel. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Uzal, Francisco Alejandro. University of California at Davis; Estados Unido

Diagnosis of Clostridium perfringens intestinal infections in sheep and goats

Clostridium perfringens produces disease in sheep, goats and other animal species, most of which are generically called enterotoxemias. This micro-organism can be a normal inhabitant of the intestine of most animal species including humans, but when the intestinal environment is altered by sudden changes in diet or other factors, C. perfringens proliferates in large numbers and produces several potent toxins that are absorbed into the general circulation or act locally with usually devastating effects on the host. History, clinical signs and gross post-mortem findings are useful tools for establishing a presumptive diagnosis of enterotoxaemia by C. perfringens in sheep and goats, although no definitive diagnosis of these diseases can be made without laboratory confirmation. Because all types of C. perfringens can be normal inhabitants of the intestine of most animals, culture of this micro-organism from intestinal contents of animals has no diagnostic value unless a colony count is performed and large numbers (usually more than 104–107 CFU/g) of C. perfringens are found. The most accepted criterion in establishing a definitive diagnosis of enterotoxaemia by C. perfringens is the detection of its toxins in intestinal contents. However, some of the major toxins of C. perfringens (i.e. epsilon toxin) can also be found, albeit in small amounts, in the small intestine of clinically normal sheep, and this poses a diagnostic challenge. In such cases the histopathology of the brain must be used as an alternative diagnostic tool, since the lesions produced by epsilon toxin in the brains of sheep and goats are unique and pathognomonic for C. perfringens type D enterotoxaemia. Ancillary tests, such as measurement of urine glucose or observation of Gram stained smears of intestinal mucosa can be used and, although they have a presumptive diagnostic value when positive, they cannot be used to rule out a diagnosis of enterotoxaemia if they are negative. In conclusion, the diagnosis of C. perfringens infections in animals is complex and it is appropriate to rely on a combination of diagnostic techniques rather than one singe test.Fil: Uzal, Francisco Alejandro. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. University of California Davis; Estados Unido

Clostridium piliforme infection (Tyzzer disease) in horses: retrospective study of 25 cases and literature review

Tyzzer disease (TD) is caused by Clostridium piliforme, a gram-negative and obligate intracellular bacterium. The disease occurs in multiple species. A triad of lesions, namely colitis, hepatitis, and myocarditis, is described in cases of TD in some species, such as rats and mice. We carried out a retrospective analysis of 25 equine cases with a diagnosis of TD; 24 of 25 cases occurred in foals <45 d old; the remaining foal was 90 d old. There were 12 males and 12 females; no sex information was available for one foal. The affected breeds were Quarter Horse, Thoroughbred, Arabian, Paint, and Hanoverian. Most of the cases (19 of 25) occurred in the spring. There were 9 cases of sudden death; the remaining animals had diarrhea, fever, distended abdomen, depression, weakness, non-responsiveness, and/or recumbency. Gross findings included icterus, hepatomegaly with acinar pattern, serosal hemorrhages, pulmonary edema, and/or fluid content in small and large intestine. Microscopically, all foals had severe, multifocal, necrotizing hepatitis. Necrotizing lymphohistiocytic colitis was observed in 10 of 25 foals, and multifocal necrotizing myocarditis was found in 8 of 25. Gram-negative, Steiner-positive, intracytoplasmic filamentous bacteria were observed in hepatocytes, enterocytes, and myocardiocytes, respectively. PCR detected C. piliforme DNA in the liver (24 of 24), colon (20 of 24), and heart (5 of 25). Our results indicate that necrotic hepatitis is the hallmark of TD in horses; the so-called triad of lesions is not a consistent characteristic of the disease in this species.Fil: García, Juan Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; ArgentinaFil: Navarro, Mauricio A.. University of California at Davis; Estados Unidos. Universidad Austral de Chile; ChileFil: Fresneda, Karina. University of California at Davis; Estados UnidosFil: Uzal, Francisco Alejandro. University of California at Davis; Estados Unidos. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Reação em cadeia da polimerase para detecção de Clostridium chauvoei em tecidos de Cavia porcellus

O objetivo deste trabalho foi padronizar uma técnica de reação em cadeia da polimerase (PCR), para detecção de Clostridium chauvoei, em tecidos fixados em formol e incluídos em parafina de cobaias (Cavia porcellus) experimentalmente infectadas com esse microrganismo. Os animais foram sacrificados, e amostras do músculo da área de inoculação (MAI), fígado, miocárdio e baço foram disponibilizadas para a técnica de PCR. O clostrídio foi detectado em todas as secções do MAI, fígado e miocárdio, mas não foi observado em secções do baço. Reações cruzadas não foram observadas a partir de secções do MAI dos animais com inoculação de outras espécies de clostrídios, bem como nenhuma amplificação foi observada a partir de secções do MAI dos animais controle. Esses resultados mostram que a técnica de PCR desenvolvida neste estudo, pode ser usada para detecção de Clostridium chauvoei em tecidos fixados em formol e incluídos em parafina

Reação em cadeia da polimerase para detecção de Clostridium chauvoei em tecidos de Cavia porcellus

The objective of this work was the standardization of a polymerase chain reaction (PCR) for detection of Clostridium chauvoei in formalin-fixed, paraffin-embedded tissues of guinea-pigs (Cavia porcellus) infected experimentally with this microorganism. The animals were sacrificed, and samples of muscle from inoculation area (MIA), liver, myocardium and spleen were available for PCR technique. Clostridium chauvoei was detected in all sections of the MIA, liver and myocardium, and no product was observed in sections of the spleen. Cross-reactions were not observed in sections of MIA of the animals inoculated with other clostridia, as well as no amplification was observed in sections of MIA of control animals. These results show that the PCR technique developed in this study may be useful for detection of C. chauvoei in formalin-fixed, paraffin-embedded tissues.O objetivo deste trabalho foi padronizar uma técnica de reação em cadeia da polimerase (PCR), para detecção de Clostridium chauvoei, em tecidos fixados em formol e incluídos em parafina de cobaias (Cavia porcellus) experimentalmente infectadas com esse microrganismo. Os animais foram sacrificados, e amostras do músculo da área de inoculação (MAI), fígado, miocárdio e baço foram disponibilizadas para a técnica de PCR. O clostrídio foi detectado em todas as secções do MAI, fígado e miocárdio, mas não foi observado em secções do baço. Reações cruzadas não foram observadas a partir de secções do MAI dos animais com inoculação de outras espécies de clostrídios, bem como nenhuma amplificação foi observada a partir de secções do MAI dos animais controle. Esses resultados mostram que a técnica de PCR desenvolvida neste estudo, pode ser usada para detecção de Clostridium chauvoei em tecidos fixados em formol e incluídos em parafina

Sarcocystosis in wild red deer (Cervus elaphus) in Patagonia, Argentina

Sarcocystis spp. are protozoan parasites with a heteroxenous life cycle, which produce cysts in the muscle of herbivorous animals. In these animal species, sarcocystosis is frequently asymptomatic, although it may occur with high prevalence. Seven Sarcocystis spp. have been described in red deer (Cervus elephus). The aim of this study was to determine the prevalence of sarcocystosis, and to perform the morphological and molecular characterization of Sarcocystis spp. found in wild red deer of the Nahuel Huapi National Park (NHNP), Patagonia, Argentina. Full necropsies of 62 red deer killed by hunters in the NHNP and neighboring areas were performed. Samples of heart and skeletal muscle were examined histologically and selected samples were also examined by transmission electron microscopy (TEM), PCR and sequencing. Sarcocystis spp. thin walled cysts were detected in 62 % (38/62) of heart, and in 22 % (3/14) of skeletal muscle samples examined histologically. TEM revealed a smooth and thin cyst wall (≤1 μm), with scarce and separated ribbon-like protrusions. A total of three partial and one full 18S ribosomal RNA (rRNA) gene sequences were obtained, and showed the highest identity (≥99 %) with Sarcocystis taeniata, a species described in moose (Alces alces). The morphological and molecular results indicate that red deer in Argentina are frequently infected with S. taeniata, a species for which the definitive host is unknown. The present results also confirm that Sarcocystis spp. using cervids as intermediate host are not host-specific. Further studies are needed to improve the epidemiological knowledge of Sarcocystosis in red deer.Fil: Chang Reissig, Elizabeth. Administración de Parques Nacionales. Delegación Regional Patagonia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Moré, Gastón Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Massone, Adriana Raquel. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Uzal, Francisco Alejandro. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentin

Equine leukoencephalomalacia (ELEM) due to fumonisins B1 and B2 in Argentina 1

The animals were on a pasture of native grasses and supplemented ad libitum with corn kernels and wheat bran. Three horses were observed having acute neurologic signs including blindness, four leg ataxia, hyperexcitability, aimless walking and circling, followed by death in two of them. Four other horses were found dead overnight without a history of neurologic signs. The morbidity, mortality and lethality rates were 11.6%, 10% and 85.7%, respectively. Grossly, the brain showed focal areas of hemorrhage, brown-yellow discoloration and softening of the sub-cortical white matter. The microscopic brain lesions consisted of extensive areas of malacia within the white matter of the cerebral hemispheres, brainstem and cerebellum, characterized by rarefaction of the white matter with cavitations filled with proteinaceous edema, multifocal hemorrhages and mild infiltration by neutrophils, and rare eosinophils. Swollen glial cells with abundant eosinophilic cytoplasm, distinct cell borders, intracytoplasmic deeply eosinophilic globules and eccentric, hyperchromatic, occasionally pyknotic nucleus were present throughout the areas of rarefaction hemorrhage, edema and necrosis. The feed supplements contained 12,490μg/kg of fumonisin B1 and 5,251μg/ kg of fumonisin B2. This is the first reported outbreak of ELEM associated with consumption of feed supplements containing high concentrations of fumonisins in Argentina

Extranodal follicular lymphoma in the lung of a free-ranging red deer (Cervus elaphus)

A hunted free-ranging female red deer (Cervus elaphus) from a region near the Nahuel Huapi National Park, Northern Patagonia, Argentina, had a focally extensive peribronchial lymphoid proliferative lesion in the lung characterized by formation of multiple follicles, with prominent germinal centers lacking mantle zone cells and antigen-related polarity. On examination of immunohistochemically stained tissues, a predominance of B cells (cluster of differentiation [CD]20 positive) with only a few scattered T cells (CD3 positive) were present. The histologic and immunohistochemical characteristics are consistent with follicular lymphoma, which is frequently seen in human beings and less frequently in domestic animals.Fil: Chang Reissig, Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Cátedra de Patología General Veterinaria; ArgentinaFil: Valli, Victor E. University of California at Davis; Estados UnidosFil: Pesavento, Patricia. University of California at Davis; Estados UnidosFil: Massone, Adriana Raquel. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Cátedra de Patología General Veterinaria; ArgentinaFil: Iovanitti, Beatriz. Servicio Nacional de Salud y Calidad Agroalimentaria. Bariloche; ArgentinaFil: Gimeno, Eduardo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Cátedra de Patología General Veterinaria; ArgentinaFil: Uzal, Francisco Alejandro. University of California; Estados Unido