Depicting "arms race" of Rhipicephalus microplus and its host on a single frame platform.

Abstract

To improve our knowledge on host-parasite interaction, the study was undertaken on Rhipicephalus microplus infestation in cross breed cattle. This tick, being a voracious blood sucker, remains attached to the skin for prolonged period and inoculates saliva during blood feeding. Biomolecules present in the saliva have detrimental effects on host system. The present study deals with the effects of R. microplus in artificially infected nine months old cattle for a period of 21 days. There was physiological alteration during tick infestation in terms of body temperature, pulse, and respiration rate. There was drop in haemoglobin gram percentage, platelet count, total red and white blood cell count. Thrombocytopenia in infested animals was suggestive of iron deficient anaemia after artificial infestation. R. microplus infestation was found to induce stress in experimental animals. Our study on peripheral blood gene expression was suggestive of Th2 polarization since there was increased IL-4 response. Increased IL-6 response indicated skin damage due to R. microplus infestation and we further correlate eosinophilia with up-regulation of IL-6 and IL-8 responses. Increased IL-10 response and decreased IFN-γ response were suggestive of immunosuppressive and anti-inflammatory properties of tick saliva.