Mycobacterium paratuberculosis detection in cow's milk in Argentina by immunomagnetic separation-PCR

Abstract The aim of this study was to standardize a diagnosis procedure to detect Mycobacterium avium subsp. paratuberculosis (Map) DNA in raw cow milk samples under field conditions. A procedure that combines both immunomagnetic separation and IS900 -PCR detection (IMS-IS1 PCR) was employed on milk samples from 265 lactating Holstein cows from Map infected and uninfected herds in Argentina. IMS-IS1 PCR results were analyzed and compared with those obtained from milk and fecal culture and serum ELISA. The extent of agreement between both tests was determined by the Kappa test. IMS-IS1 PCR showed a detection limit of 101 CFU of Map/mL of milk, when 50:50 mix of monoclonal and polyclonal antibodies were used to coat magnetic beads. All of the 118 samples from the Map uninfected herds were negative for the set of the tests. In Map infected herds, 80 out of 147 cows tested positive by milk IMS-IS1 PCR (55%), of which 2 (1.4%) were also positive by milk culture, 15 (10%) by fecal culture, and 20 (14%) by serum ELISA. Kappa statistics (95% CI) showed a slight agreement between the different tests (<0.20), and the proportions of agreement were ≤0.55. The IMS-IS1 PCR method detected Map in milk of the cows that were not positive in other techniques. This is the first report dealing with the application of IMS-IS1 PCR in the detection of Map in raw milk samples under field conditions in Argentina.

Hypothyroid associated polyneuropathy in dogs: report of six cases / Polineuropatia associada a hipotireoidismo em cães: relato de seis casos

Six Doberman Pinscher, between six and eight years of age, were presented to the Veterinary Hospital from Faculty of Veterinary Science of The University of Buenos Aires. Neurological examination revealed tetraparesis with inability to walk, decreased muscle tonus and myotatic reflexes in all dogs. Serum cholesterol levels, creatine kinase and alkaline phosphatase activities were mildly to markedly elevated, and tibial motor nerve conduction velocities were slow in all dogs. Basal measurements of free T4 and TSH were determined by radioimmunoassay. Although fT4 values were within normal range, in all dogs TSH values were elevated. Based on this results, hypothyroidism was diagnosed and a supplementation therapy was established with oral levothyroxine (T4). Two weeks after treatment has been started, all patients had an improvement in clinical signs, and within a month gait became normal, as well as muscular tonus and spinal reflexes.

Seis Dobermans Pinscher, entre seis e oito anos de idade, foram encaminhados ao Hospital Veterinário da Faculdade de Ciências Veterinárias da Universidade de Buenos Aires. O exame neurológico revelou tetraparesia com incapacidade para andar, diminuição do tono muscular e de reflexos miotáticos em todos os cães. Os níveis de colesterol, creatina quinase e fosfatase alcalina encontravam-se de moderada a acentuadamente elevados. As velocidades de condução nervosa do nervo tibial estavam diminuídas em todos os cães. Os níveis séricos basais de T4 livre e TSH foram determinados por radioimunoensaio e, embora os valores de T4 livre estivessem dentro dos limites de normalidade, em todos os cães o TSH estava elevado. Baseado nestes resultados, diagnosticou-se hipotireoidismo e iniciou-se uma suplementação oral com levotiroxina (T4). Duas semanas após o início do tratamento todos os pacientes tiveram melhora clínica e, dentro de um mês a locomoção, o tono muscular e os reflexos medulares tornaram-se normais.