Inoculación experimental de Escherichia Coli K99+ST+ en terneros. Estudio clínico y anátomo patológico

Se reprodujo experimentalmente la colibacilocis en terneros recien nacidos, con el objetivo de determinar la respuesta clinica y anatomo patologica. Se utilizaron 19 animales Holstein Friesian asignados aleatoriamente en 4 grupos; el grupo 1 constituido por terneros que ingirieron calostro, los 3 restantes constituidos por individuos privados de calostro. En la inoculacion se empleo una cepa de Escherichia coli K99+ enterotoxigenica, en una dosis de 100 ml de inoculo via oral, con una concentracion de 6 x 10 8  unidades formadoras de colonias (UFC) por ml. Los grupos II y III, una vez aparecida la signologia fueron tratados con gentamicina, suero polionico y suero glucosado al 5%. Los individuos tratados respondieron favorablemente a los farmacos administrados. Las muertes atribuidas al cuadro experimental solo se presentaron en el grupo IV, no tratados. Las lesiones macro y microscopicas son coincidentes con las establecidas en la literatura. Palabras claves: E. coli, diarrea, terneros. Abstract Colibacillosis was experimentaly produced in newlyborn calves ira orden to determine the clinical and anatomical pathologic response. Nineteen Holstein Friesian calves were randomly assigned to four groups: group I consisted of calves which ingested colostrum and the other 3 groups consisted of colostrum-deprived calves. An enterotoxigenic strain of Escherichia coli K99+ was employed for the inoculation, in a doce of 100 ml of inoculum per os of an inoculum containing 6 x 10 8  colony-forming units per ml. Groups II and III were treated as soora as clinical signs appeared, with gentamicin, electrolytes and 5% glucose solution. Treated calves responded favorably to the drugs adrninistered. Deaths atributed to exper-mentally-induced disease were only obserbed in Group IV, untreated calves. The macro and miscroscopy lesions were similar to those described in the literature. Key Words: E. coli, calves, diarrhea.