imprint:
[Erscheinungsort nicht ermittelbar]: [Verlag nicht ermittelbar], 2007
Language:
English
Origination:
University thesis:
Dissertation, 2007
Footnote:
Description:
Swine dysentery is an enteric disease that is present in most pig-producing countries. It is caused by the spirochete Brachyspira hyodysenteriae and the typical manifestation is severe muco-haemorrhagic diarrhoea that may lead to a high mortality in affected herds if it is left untreated. The aim was to study the immunological and metabolic responses associated with swine dysentery. Pigs were orally inoculated with Brachyspira hyodysenteriae strain B204R after a provocative feeding regime with soy bean meal. Blood was sampled before inoculation and repeatedly during the incubation, dysentery and recovery periods. Counts of leucocyte and lymphocyte sub-populations and levels of the cytokines IL-1beta, IL-6, Il-10, TNF-alpha and IFN-gamma the acute phase protein Serum Amyolid A, glucose, lactate and 18 amino acids were determined. The experimental infection model was successful and ~65% of the pigs developed dysentery with a deterioration of the body condition and no weight gain. The presence of the pro-inflammatory cytokine IL-1beta in serum was associated with the manifestation of dysentery and the production of Serum amyloid A. During the dysentery period the numbers of monocytes, neutrophils and CD8alpha+ lymphocytes increased in the blood. Glucose and lactate levels showed no alteration during dysentery, but the serum concentrations of gluconeogenic amino acids, mainly glutamine, alanine, tyrosine and serine were decreased during that period. Most parameters were returned to their pre-inoculation levels during the recovery, but the presence of the anti-inflammatory cytokine IL-10 and the production of B. hyodysenteriae specific antibodies were associated with the recovery of sick animals. The susceptibility to disease after inoculation appeared to be related to low levels of CD8alpha+ lymphocytes and high levels of gamma/delta T cells in blood prior to inoculation. In conclusion, this thesis shows that the cellular and humoral immune responses as well as the metabolic response in blood were altered by swine dysentery.