Effect of levamisole on the clinical and immunologic responses to oral vaccine of Treponema hyodysenteriae
Jenkins, E.M.; Nash, S.; Hill, W.; Mosley, J.
American Journal of Veterinary Research 48(4): 657-660
1987
ISSN/ISBN: 0002-9645 PMID: 3296885 Document Number: 291215
Conventionally raised crossbred Hampshire pigs were vaccinated orally with attenuated Treponema hyodysenteriae in combination with an anthelmintic, levamisole or dichlorvos. Pigs in group I (n = 9) were treated with levamisole and vaccinated with attenuated T. hyodysenteriae and those in group II (n = 9) were treated with levamisole and permitted to commingle (contact exposure) with group I. Pigs in group III (n = 9) were vaccinated in a similar manner and were treated with dichlorvos. Pigs in group IV (n = 9) were treated with dichlorvos and permitted to commingle with group III. Control pigs (group V; n = 9) were not given any anthelmintic, nor were they vaccinated; they were housed separately. During the 8-week interval between vaccination and challenge inoculation, 4 total days and 8 total days of diarrhea were observed in pigs in groups I and II, respectively. Likewise, 5 total days and 10 total days of diarrhea were seen in groups III and IV, respectively. In all groups, the pigs tended to shed the organism in their feces after they were vaccinated or challenge inoculated, as determined by a fluorescent antibody technique (FAT) and culture procedure (CP). Overall mean shedding patterns of 5.5% and 24.5% identified by CP and FAT, respectively, were seen in the 2 levamisole-treated groups (I and II). In contrast, mean shedding patterns of 4% and 18% of the isolation attempts were detected by CP and FAT, respectively, in th 2 dichlorvos-treated groups. Diarrhea and shedding of T. hyodysenteriae in the controls (group V) did not occur. During the 4-week interval after pigs were challenge inoculated, diarrhea was seen for 1 day in groups I and II, for 2 days in groups III and IV, and for 121 days in the control group. The T. hyodysenteriae shedding patterns increased numerically to overall means of 12.5%, as determined by CP and 32% as determined by FAT for the levamisole-treated groups. There was an overall mean decrease to 2.5% shedding as determined by CP and an increase to 27% as determined by FAT in the dichlorvos-treated groups. In contrast, there were sheddings of 50% and 80% as determined by CP and FAT, respectively, in the control group. Pigs given levamisole developed mean geometric titers of 1:52 and 1:62 in the dichlorvos-treated groups III and IV, respectively. After the pigs were challenge inoculated, the serum titers increased from 1:86, compared with 1:20 and 1 to 168 for the dichlorvos-treated and nontreated controls, respectively. All vaccinated groups exhibited mean positive cell-mediated immune responses after vaccination and challenge inoculation were done. The control group had a mean borderline positive cell-mediated immune response after challenge inoculation was done.