Activity of Four Antimicrobial Agents Against Porcine Serpulina pilosicoli Isolates From the Midwestern United States

1998 University of Nebraska-Lincoln Extension Swine Day Report. Porcine colonic spirochetosis (PCS) is a non-fatal, diarrheal disease affecting pigs during the growing and finishing stages of production. The disease is caused by Serpulina pilosicoli, a newly recognized species of intestinal spirochetes. Because Serpulina pilosicoli is transmitted by the fecaloral route, control measures aimed at reducing environmental contamination, including sanitation and antimicrobial therapy, should be investigated. We determined the antimicrobial susceptibility of seven porcine Serpulina pilosicoli isolates recovered from pigs in the midwestern United States against four antimicrobials commonly used for control of swine dysentery, a disease caused by the related spirochete, Serpulina hyodysenteriae. All the isolates were susceptible to carbadox and tiamulin, whereas the percentages of isolates susceptible, intermediate and resistant were 66.6, 16.6 and 16.6 percent with lincomycin, and 50 percent susceptible and 50 percent resistant with gentamicin. This information is consistent with field observations about the efficacy of the respective antimicrobials for control of PCS.