Prevalence of Lawsonia intracellularis, Brachyspira hyodysenteriae and Salmonella in swine herds.

The prevalence of Lawsonia intracellularis, Brachyspira hyodysenteriae and Salmonella spp. were investigated by multiplex PCR using fecal samples of pigs with diarrhea or a history of diarrhea. The overall herd prevalence of L. intracellularis, B. hyodysenteriae and Salmonella spp. were 46.5%, 37.2% and 51.1%, respectively. Also, the prevalence of L. intracellularis, B. hyodysenteriae and Salmonella spp. among all sampled pigs were 19.9%, 10.8% and 17.7%, respectively. Seventeen of 43 herds were positive with 2 enteric organisms, and 2 herds were positive with L. intracellularis, B. hyodysenteriae and Salmonella spp. simultaneously. It was notable that 11 of 12 herds with more than 2,000 pigs were affected with Salmonella spp., and that only 2 of 12 the herds were affected with B. hyodysenteriae. This study suggested that herds positive for L. intracellularis, B. hyodysenteriae and Salmonella spp. were distributed throughout Korea, although the relationship among other pathogens such as viral or parasitic ones and/or with metabolic disorders was not determined.