Inter-host differences in immune response against H. meleagridis in poultry

The unicellular protozoan parasite Histomonas (H.) meleagridis, which belongs to the family Monocercomonadidae and class Trichomonaida, causes histomoniasis, also known as Blackhead disease. H. meleagridis is an anaerobic protozoan parasite with flagellated (8–15 mcm) and amoeboid (8–30 mcm) forms. This disease can affect turkeys, chickens, pheasants, and a variety of other gallinaceous birds. Chickens are usually asymptomatic carriers, where turkeys have a mortality rate up to 100%. H. meleagridis is primarily transmitted in the egg of cecal nematode, Heterakis gallinarum. Chickens and other gallinaceous birds act as a reservoir for Heterakis gallinarum. Nematode eggs infected with H. meleagridis remain viable in the environment for years. Cloacal drinking, in which reverse peristalsis rapidly uptakes things into the cloaca and transmits them to the cecae, can fast transmit disease in turkeys. The pathognomonic ulceration of the ceca and necrotic lesions in the liver are used to diagnose histomoniasis. To date, no approved therapeutics or prophylactics exist to treat histomoniasis, causing morbidity and mortality in poultry. The poultry industry is suffering significant economic losses as a result of this malady. An in vivo model will be set-up to study H. meleagridis in different poultry species, i.e. turkeys, chicken and pheasant. An investigation will be conducted into the host-worm interaction and its impact on poultry immunity. To research and compare immunity in poultry species, a systems immunology approach will be used. Within this project, we will translate the differences observed between poultry species into vaccines or chemoprophylactic strategies.