2008 Volume 61 Issue 2 Pages 151-156
Three surveys for infection rates of Brachyspira pilosicoli (Bp) and Brachyspira hyodysenteriae (Bh) in slaughtered pigs were conducted from February 2005 to March 2006 in Toyama, Japan. In the first survey, 16, 431 pigs from 37 farms were macroscopically investigated. Colitis was detected in 50 pigs (0.30%) and in eight farms (21.6%). Of the 50 pigs, Bp was isolated from one pig (2%), and Bh was isolated from 45 pigs (90%). In the second survey, 2, 810 pigs produced in the Bp-contaminated farm were examined macroscopically, and 20 pigs (0.71%) were affected with colitis. Among the pigs, Bp was isolated from two pigs (10%), and Bh wasisolated from 15 pigs (75%). In the third survey, the infection rate was investigated in 50 pigs without colitis macroscopically in the Bp-contaminated farm. Three pigs (6%) and 13 pigs (26%) were infected with Bp and Bh, respectively. These results indicate that some pigs have Bp and Bh without gross lesions or clinical signs on farms contaminated with Bp. Such asymptomatic carriers may be a major source of Bp and Bh infections. Special care is required to prevent contamination of meat with this bacterium, because Bp is a zoonotic pathogen.
