PATHOPHYSIOLOGICAL EFFECTS OF ORAL INOCULATION OF GROWING PIGS WITH SALMONELLA ENTERICA SEROVARS TYPHIMURIUM OR CHOLERAESUIS

Enteric pathogens are responsible for major economic losses in the swine industry. In the U.S., Salmonella enterica subspecies enterica serovar Typhimurium (ST) and serovar Choleraesuis (SC) account for essentially all cases of salmonellosis in swine. Previous studies documented that oral ST eroded growth and produced unmistakable changes in the endocrine stress and somatotropic axis of young growing pigs. However, these effects occurred in the absence of elevated systemic inflammatory cytokines that were previously thought to accompany disease-associated growth retardation. In the current study, it was hypothesized that SC would produce very different systemic inflammatory cytokine responses compared to ST given the likelihood of SC to produce systemic disease in pigs. Weaned pigs were housed two per pen with free access to feed and water during a 14 d experiment. On d 0, pigs were fed either 108 CFU SC or 108 ST, and bacteria were re-fed twice weekly through the course of the experiment. Control pigs were fed dough without bacteria. Serum was collected on d 0, 7, and 14 for determination of tumor necrosis factor alpha (TNFα), interleukin-1beta (IL-1β), and insulin-like growt