Immunocytochemistry of Psoroptes cuniculi stained by sera from naive and infested rabbits: preliminary results.

Immunocytochemistry was used to identify possible target antigens in the digestive system of Psoroptes cuniculi. Sera from three recently acutely infested rabbits, from rabbits with a mild long lasting infestation, and from a rabbit with repeated mite infestations and no longer able to maintain a population of P. cuniculi were used to determine any antibody specificity to the mite digestive system. The reactivity of these sera was compared with sera from three un-infested animals. The different pool of sera targeted different mite antigens; in particular, sera from the resistant rabbit and the chronically infested rabbits reacted with gut cells, faecal material and cuticle, while sera from the recently infested rabbits reacted with gut contents, faecal material and cuticle of the parasites but not with gut cells. Finally, sera from un-infested rabbits did not demonstrate any specificity to P. cuniculi antigens reacting only with mite gut contents in a weak manner. These preliminary data suggest the presence of antibodies induced in the host blood by infection, which act against the parasite by binding to antigen at the surface of its gut.