Prevention of Disease in Ferrets Fed an Inactivated Whole Cell Campylobacter jejuni Vaccine

Ferrets were used to demonstrate the potential of a killed whole cell vaccine prepared from Campylobacter jejuni to protect against disease. C. jejuni strain 81 176 was grown in BHI broth, formalin-fixed, and resuspended in PBS to a concentration of 1010 cells per ml. This vaccine (CWC) or live organisms were delivered orally with a nasogastric tube into anesthetized animals treated to reduce gastric acidity and intestinal motility. When 5 1010 CFU of the vaccine strain (Lior serotype 5) or one of two other serotypes, CGL-7 (Lior 4) or BT44 (Lior 9), was used to challenge the ferrets, all of the animals developed a mucoid diarrhea. If the animals had been challenged with 5 109 CFU of the homologous strain 1 month before challenge with 1010 CFU, 80 100% protection against disease was seen. This protection was also obtained after an initial exposure to the 81 176 strain followed by challenge with either of the heterologous strains. CWC was used to see if protection demonstrated with the live organisms could be produced with the non-living preparation. When 109 cells of CWC was given as two doses 7 days apart with or without 25 g of a coadministered mucosal adjuvant, LTR192G, only 40 60% of the animals were protected. If the regimen was changed to four doses given 48 h apart, 80% of the animals were free of diarrhea after subsequent challenge. Increasing the number of cells in the four dose regimen to 1010 cells did not improve protection. Animals given four doses of 1010 cells combined with LTR192G were subsequently challenged with 1010 cells of the homologous strain or the heterologous strain CGL-7. The CWC protected against both strains. Serum IgG antibody titers determined by ELISA showed little increase following the CWC four dose vaccination regimen, compared to animals given one dose of the live organism. Pub. in Vaccine v23, p4315-4321, 2005.