Avaliação clínica da infecção experimental de bezerros com Salmonella Typhimurium / Clinical evaluation of experimental Salmonella Typhimurium-infection in calves

ABSTRACT

The clinical conditions of healthy calves infected with 10(9) CFU of Salmonella Typhimurium were evaluated and the viability of the experimental model in disease induction was verified. Twelve male Holstein calves, 10 to 15-days old, were examined. They were allocated into two groups, control and experimentally infected. Animals were submitted to clinical examination after inoculation and at every 24 hours, during six days after infection. Samples of rectal swabs were collected for Salmonella Typhimurium isolation. Results showed that all animals had different degrees of diarrhea, with mucus and bleeding, 24 to 72 hours after experimental infection with Salmonella Typhimurium, accompanied by fever, but no signs of sepsis. The isolation of Salmonella Typhimurium from rectal swabs occurred 24 hours after the infection and there were no deaths during the experiment, which means that this sorovar has an epidemiological importance related to the intermitent or continuous elimination of the bacterium. Results also showed that the oral administration of 10(9) CFU of Salmonella Typhimurium induces clinical signs of salmonellosis in 10 to 15-day-old calves.