Shimelis Dagnachew
Addis Ababa University, Ethiopia
Title: Cytokines responses by young zebu cattle infected with Trypanosoma vivax from tsetse infested and non-tsetse infested areas of Northwest Ethiopia
Biography
Biography: Shimelis Dagnachew
Abstract
Immune reactions do not always lead to protection in trypanosomoses, though they appear to be involved in immunopathological processes. Therefore, the objective of this experimental study was to determine cytokine responses upon infection with tsetse-adapted and mechanically transmitted Trypanosoma vivax in cattle of Northwest Ethiopia. Eighteen trypanosome-naïve Bos indicus cattle were assigned randomly into three groups of six (group TT= infected with a T. vivax isolate from tsetse infested area, group NT = infected with a T. vivax isolate from non-tsetse infested area and group C=non-infected control). Each infected animal received approximately 3x106 trypanosomes intravenously. Blood samples were collected in a week interval for parasitological examination, packed cell volume (PCV) determination and cytokine assay. The experimental infection caused an acute disease with detectable parasitaemia from 5 and 12 days and peak parasitaemia 8 and 14 days post infection for NT and TT infected cattle, respectively. There were significant reduction (P<0.05) after the infection in mean PCV value with 21.861.56% (TT), 22.760.90% (NT) and 30.670.64 (control). Significant increases were observed for all cytokines (P<0.05) in both the infected groups and no significant differences (P>0.05) between TT and NT groups. Interferon gamma, tumor necrosis factor alpha and interleukin-12 increased quickly at the first peak parasitaemia and persists with a steady pattern whereas an increase of interleukin-10 appeared only at the second peak parasitaemia. In conclusion, the magnitude and secretion patterns of cytokines responses were similar in TT and NT infected groups of cattle, although the responses occurred one week earlier in the later group.