In vivo evaluation of anticoccidial effect of antibody fragments expressed in pea (Pasum sativum) on Eimeria tenella sporozoites

Coccidiosis in chicken causes great economic losses. The increasing resistance of Eimeria species to anticoccidials has induced the search for alternative methods of control. In vivo antibody neutralization assay was conducted to study the inhibitory effect of nine antibody fragments (Ab1-Ab9) on Eimeria tenella sporozoites. These anti-E. tenella antibody fragments were expressed in pea plant (Pasum sativum). To assess the inhibitory effect on parasite reproduction, the in vivo antibody neutralization assay was done by retrograde infection of chicken with sporozoites previously incubated with antibody fragments. The pre-incubated sporozoites with the examined antibody fragments displayed a reduced ability to reproduce following intracloacal application to chicken (especially Ab1, Ab3, Ab5, and Ab9). Other antibody fragments (Ab2, Ab4, Ab6, Ab7, and Ab8) were less capable to reduce sporozoite infectivity and reproduction.