Improving the consistency of experimental swine dysentery inoculation strategies

AbstractSwine dysentery (SD) caused by pathogenicBrachyspira spp. is an economic challenge for the swine industry. In research settings, experimental reproduction of swine dysentery typically relies on intragastric inoculation which has shown variable success. This project aimed to improve the consistency of the experimental inoculation protocol used for swine dysentery in our laboratory. Over six experiments, we evaluated the influence of group housing in inoculated pigs using a frozen-thawed broth culture of strongly hemolyticB. hyodysenteriae strain D19 (Trial A), compared the relative virulence ofB. hyodysenteriae strains D19 and G44 (Trial B), compared inoculum volumes (50  mL vs 100 mL) for G44 andB. hampsonii 30446 (Trial C), and performed three independent trials evaluating intragastric inoculation using different oral inoculation methods: oral feed balls (Trial D), and oral syringe bolus of 100  mL (Trial E) or 300 mL (Trial F). Intragastric inoculation with a fresh broth culture ofB. hyodysenteriae strain G44 resulted in a shorter incubation period and a higher proportionate duration of mucohemorrhagic diarrhea (MMHD) compared to D19. Intragastric inoculation with either 50 or 100  mL ofB. hampsonii 30446 or B.hyodysenteriae (G44) were statistically equivalent. Oral inoculation with 100  mL or 300 mL also yielded similar results to intragastric inoculation but was more expensive due to the additional work and supplies associated with syringe training. Our fut...
Source: Veterinary Research - Category: Veterinary Research Source Type: research