Cultivation of Histomonas meleagridis from the Liver Lesions of a Hen

Abstract

BLACKHEAD (entero-hepatitis), a widespread and generally fatal disease of turkeys, was attributed to a protozoon, Amæba meleagridis, by Theobald Smith¹. Later, Tyzzer confirmed its presence in cæcal lesions and renamed it Histomonas (gen. nov.) meleagridis Smith². Although there is no difficulty in infecting young chickens experimentally with H. meleagridis (Tyzzer³) the disease produced is not severe, and the chickens soon recover clinically, though they may remain carriers, passing Protozoa in their fæces, for long periods. Theobald Smith⁴ saw Amæba (= Histomonas) meleagridis in liver sections from diseased fowls, and Tyzzer⁵ found similar lesions in a two-year-old hen. Although Drbohlav⁶ and afterwards Tyzzer⁷ cultivated Histomonas meleagridis from the cæcal discharges of experimentally infected chickens, all attempts to cultivate the parasite from diseased tissues from either turkeys or chickens failed (Tyzzer⁷).