Ferdushy, T2; Schou, T W3; Norup, Liselotte Rothmann8; Dalgaard, Tina Sørensen8; Thamsborg, Stig Milan4; Nejsum, Peter5; Permin, Anders6; Juul-Madsen, Helle Risdahl8; Kyvsgaard, N C7
1 Department of Animal Science - Immunology and microbiology, Department of Animal Science, Science and Technology, Aarhus University2 Section for Parasitology and Aquatic Diseases, Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 100, DK-1870, Frederiksberg C, Copenhagen, Denmark3 Human Health and Safety, DHI, Hørsholm4 Sektion, Parasitology and Aquatic Diseases5 Department of Veterinary Disease Biology, University of Copenhagen6 DHI, Environment and Toxicology, Agern Alle 5 Hørsholm, Denmark7 Section for Production and Health, Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Grønnegårdsvej 2, DK-1870, Frederiksberg C, Copenhagen, Denmark8 Department of Animal Science - Immunology and microbiology, Department of Animal Science, Science and Technology, Aarhus University
Acquired resistance against Ascaridia galli infection was studied in seventy-two 18-week-old white Leghorn chickens allocated to six groups (G1–G6). In order to understand the population dynamics following trickle-infection (100 eggs per chicken twice weekly), chickens of subgroups of G1 were necropsied 3 days after 1, 6 or 12 inoculations (G1A, G1B and G1C respectively), while G2–G4 were inoculated for 6 weeks. G2 was necropsied 4 weeks after the last inoculation. The number of established larvae increased initially (between G1A and G1B) but decreased after repeated inoculations (G1C, G2). G3, G4 and G5 were used to measure the efficacy of anthelminthic treatment and to monitor the acquisition of resistance following a challenge infection. At week 7 G3, G4 and G5 were treated with flubendazole for 7 days in the feed. Two weeks after treatment the chickens in G4 and G5 were challenged with 500 eggs. G6 was left as uninfected control. Necropsy at week 10 after first inoculation revealed a lower establishment rate, an impaired development and a more posterior localization of the larvae in G4 (trickle-infected-treated-challenged) compared with G5 (treated-challenged). IgY level in serum reached noticeable level at 14 dpi in G2 and G4 chickens, and in G4 chickens IgY level further increased after challenge infection. The study provides evidence that acquired resistance against A. galli in chickens leads to a significant yet incomplete protection against re-infection.
Parasitology (cambridge), 2014, Vol 141, Issue 12, p. 1603-1610