Long term shedding of Salmonella choleraesuis following experimental infection of very young piglets

In the United States, more than 90% of diagnosed swine salmonellosis cases can be attributed to infections by Salmonella Choleraesuis, the etiologic agent of swine paratyphoid (9). Salmonellosis caused by this serotype is primarily manifested as a post weaning septicentia or enterocolitis and often occurs on operations that comntingle pigs of different ages (9). Salmonella Choleraesuis is rarely isolated from sources other than swine which suggests an important role of carrier swine in the spread of this host adapted pathogen (4-6, 9). Since Salmonella Choleraesuis infections can recur in pigs previously infected, an important role for latent carriers is further implicated (9). The development of a Salmonella Choleraesuis carrier state has been investigated experimentally with weaned piglets (1, 4- 6) but not much is known regarding the potential of neonatal piglets to become long term carriers. This may be because neonatal piglets, while capable of beconting infected, rarely exhibit clinical salmonellosis (9). The objective of the present study was to experimentally infect suckling piglets with Salmonella Choleraesuis and then examine their daily shedding pattern and pattern of tissue colonization well beyond the initial infection period