RESUMEN

Rotavirus A (RVA) causes diarrhea in calves and frequently possesses the G6 and P[5]/P[11] genotypes, whereas G8 is less common. We aimed to compare RVA infections and G/P genotypes in beef and dairy calves from major livestock regions of Argentina, elucidate the evolutionary origin of a G8 strain and analyze the G8 lineages, infer the phylogenetic relationship of RVA field strains, and investigate the evolution and spatio-temporal dynamics of the main G6 lineages in American countries. Fecal samples (n = 422) from diarrheic (beef, 104; dairy, 137) and non-diarrheic (beef, 78; dairy, 103) calves were analyzed by ELISA and semi-nested multiplex RT-PCR. Sequencing, phylogenetic, phylodynamic, and phylogeographic analyses were performed. RVA infections were more frequent in beef (22.0%) than in dairy (14.2%) calves. Prevalent genotypes and G6 lineages were G6(IV)P[5] in beef (90.9%) and G6(III)P[11] (41.2%) or mixed genotypes (23.5%) in dairy calves. The only G8 strain was phylogenetically related to bovine and artiodactyl bovine-like strains. Re-analyses inside the G8 genotype identified G8(I) to G8(VIII) lineages. Of all G6 strains characterized, the G6(IV)P[5](I) strains from "Cuenca del Salado" (Argentina) and Uruguay clustered together. According to farm location, a clustering pattern for G6(IV)P[5] strains of beef farms was observed. Both G6 lineage strains together revealed an evolutionary rate of 1.24 × 10-3 substitutions/site/year, and the time to the most recent common ancestor was dated in 1853. The most probable ancestral locations were Argentina in 1981 for G6(III) strains and the USA in 1940 for G6(IV) strains. The highest migration rates for both G6 lineages together were from Argentina to Brazil and Uruguay. Altogether, the epidemiology, genetic diversity, and phylogeny of RVA in calves can differ according to the production system and farm location. We provide novel knowledge about the evolutionary origin of a bovine G8P[11] strain. Finally, bovine G6 strains from American countries would have originated in the USA nearly a century before its first description.

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An outbreak of systemic granulomatous disease of unknown etiology was diagnosed in a dairy herd from Argentina. Eleven out of 211 cows manifested hyperthermia, depression, alopecia, pruritus, decreased milk production and death in most cases. During necropsy, multifocal petechial hemorrhages in glottis and vulva, white multifocal nodules in the liver and splenomegaly with subcapsular petechial hemorrhages were observed. Both kidneys were diffuse pale and enlarged. Systemic granulomatous hepatitis, myocarditis, pancreatitis and nephritis were observed. Water and food samples tested negative for Arsenic and T2 toxin, respectively. Fusarium equiseti was isolated from alfalfa hay samples. Vicia spp. was not consumed by the affected herd and no other cause of vetch-like disease was registered. Other causes of granulomatous lesions (Mycobacterium spp. and fungal infections) were discarded. The systemic granulomatous disease was suggestive of a type IV hypersensitivity reaction. Although the sensitizing agent was not determined, two components of the ration were suspected: cotton seed and bone ash. Both of them were introduced one month prior to the detection of the first affected cow and the disease resolved since they were removed from the diet.(AU)

Asunto(s)

RESUMEN

An outbreak of systemic granulomatous disease of unknown etiology was diagnosed in a dairy herd from Argentina. Eleven out of 211 cows manifested hyperthermia, depression, alopecia, pruritus, decreased milk production and death in most cases. During necropsy, multifocal petechial hemorrhages in glottis and vulva, white multifocal nodules in the liver and splenomegaly with subcapsular petechial hemorrhages were observed. Both kidneys were diffuse pale and enlarged. Systemic granulomatous hepatitis, myocarditis, pancreatitis and nephritis were observed. Water and food samples tested negative for Arsenic and T2 toxin, respectively. Fusarium equiseti was isolated from alfalfa hay samples. Vicia spp. was not consumed by the affected herd and no other cause of vetch-like disease was registered. Other causes of granulomatous lesions (Mycobacterium spp. and fungal infections) were discarded. The systemic granulomatous disease was suggestive of a type IV hypersensitivity reaction. Although the sensitizing agent was not determined, two components of the ration were suspected: cotton seed and bone ash. Both of them were introduced one month prior to the detection of the first affected cow and the disease resolved since they were removed from the diet.

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Actinobacillosis is a common cause of sporadic infection in cattle. It was mostly characterized as a pyogranulomatous inflammation of the tongue, but also soft tissues as lymph nodes, other digestive tract localization and skin. The aim of this study was to describe an episode of granulomatous dermatitis and lymphadenitis affecting a bull herd in Argentina during 2010. Actinobacillus lignieresii was isolated from samples collected from one of the affected bulls, and characteristic lesions were observed. Lesions other than 'wooden tongue' are usually uncommon; however, actinobacillosis should be included as a differential diagnosis for cutaneous diseases.

A actinobacilose é causa comum de infecções esporádicas em bovinos. Esta afeção tem sido caracterizada como uma infecção piogranulomatosa não somente da língua como também de tecidos moles tais como linfonodos, ou outras localizações no trato digestivo e na pele. O objetivo do presente trabalho é descrever um episódio de dermatite piogranulomatosa e linfadenite que afetou um rebanho de touros na Argentina em 2010. As amostras recolhidas de um dos animais afetados permitiram o isolamento de Actinobacillus lignieresii. Observaram-se as lesões características da doença. Habitualmente não são comuns outras lesões para além das descritas como "língua de pau", no entanto, a actinobacilose deve ser incluída como um possível diagnóstico diferencial de doenças cutâneas.

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RESUMEN

Actinobacillosis is a common cause of sporadic infection in cattle. It was mostly characterized as a pyogranulomatous inflammation of the tongue, but also soft tissues as lymph nodes, other digestive tract localization and skin. The aim of this study was to describe an episode of granulomatous dermatitis and lymphadenitis affecting a bull herd in Argentina during 2010. Actinobacillus lignieresii was isolated from samples collected from one of the affected bulls, and characteristic lesions were observed. Lesions other than 'wooden tongue' are usually uncommon; however, actinobacillosis should be included as a differential diagnosis for cutaneous diseases.(AU)

A actinobacilose é causa comum de infecções esporádicas em bovinos. Esta afeção tem sido caracterizada como uma infecção piogranulomatosa não somente da língua como também de tecidos moles tais como linfonodos, ou outras localizações no trato digestivo e na pele. O objetivo do presente trabalho é descrever um episódio de dermatite piogranulomatosa e linfadenite que afetou um rebanho de touros na Argentina em 2010. As amostras recolhidas de um dos animais afetados permitiram o isolamento de Actinobacillus lignieresii. Observaram-se as lesões características da doença. Habitualmente não são comuns outras lesões para além das descritas como "língua de pau", no entanto, a actinobacilose deve ser incluída como um possível diagnóstico diferencial de doenças cutâneas.(AU)

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Se investigó la posible influencia de la vacuna antiaftosa con adyuvante oleoso sobre la respuesta a la tuberculina PPD, y sobre el nivel de anticuerpos séricos anti-Micobacterium bovis determinado por un enzimoinmunoensayo (ELISA). Los resultados obtenidos en ambas pruebas diagnósticas de tuberculosis, antes y después de dos vacunaciones con vacuna antiaftosa con adyuvante oleoso no mostraron interferencia de esa vacuna sobre la especificidad de las respuestas tuberculínicas o de los niveles de anticurpos anti-M.bovis. Se analizó tambiém la presencia de anticuerpos anti-M.paratuberculosis por ELISA

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