Experimental Salmonella Typhimurium infection in pigs

The genus Salmonella, particularly Salmonella enterica subsp. enterica serovars Choleraesuis and Typhimurium, poses significant challenges to swine production and leads to economic losses from conditions such as septicemia and enterocolitis. We evaluated the effects of experimental infection with Salmonella Typhimurium on clinical signs and anatomopathologic outcomes in pigs. Twenty 90-d-old pigs were divided into 2 groups: G1 received an oral inoculum of 10⁸ cfu of Salmonella Typhimurium; G2 served as a control. Pigs were monitored clinically for 30 d; postmortem examinations and microbiologic analyses were conducted. No significant differences were found in rectal temperature or weight between groups; however, diarrhea episodes were noted in the challenged group starting on day 5 post-inoculation. Isolates of Salmonella Typhimurium were detected intermittently in the challenged group; all positive samples came from pigs without diarrhea. Macroscopic lesions in G1 pigs included button-shaped ulcers in the ileocecal region, enlarged or hemorrhagic mesenteric lymph nodes, and hyperplasia of lymphoid tissue in the colon.