Experimental Neospora caninum infection in chickens (Gallus gallus domesticus) with oocysts and tachyzoites of two recent isolates reveals resistance to infection

Autor(es):Mostrar menos -

Oliveira, Solange ^[1] ; Aizawa, Juliana ^[1] ; Soares, Herbert Sousa ^[1] ; Chiebao, Daniela Pontes ^[1] ; de Castro, Martio Botelho ^[2] ; Hora, Aline S. ^[1] ; Lopes, Marcos Gomes ^[1] ; Schares, Gereon ^[3] ; Jenkins, Mark C. ^[4] ; Kwok, Oliver C. H. ^[4] ; Dias, Ricardo Augusto ^[1] ; Gennari, Solange Maria ^[1] ; Dubey, Jitender P. ^[4] ; Jesus Pena, Hilda Fatima ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Vet Med, Dept Prevent Vet Med & Anim Hlth, Av Prof Dr Orlando Marques de Paiva 87, BR-05508000 Sao Paulo, SP - Brazil

^[2] Univ Brasilia, Lab Vet Pathol, Hosp Vet, Darcy Ribeiro Univ Campus, Via L4 Norte, BR-70910970 Brasilia, DF - Brazil

^[3] Friedrich Loeffler Inst, Fed Res Inst Anim Hlth, Inst Epidemiol, Sudufer 10, D-17493 Greifswald - Germany

^[4] ARS, Anim Parasit Dis Lab, Beltsville Agr Res Ctr, USDA, Beltsville, MD 20705 - USA

• Tipo de documento: Artigo Científico
• Fonte: International Journal for Parasitology; v. 48, n. 2, p. 117-123, FEB 2018.
• Citações Web of Science: 3

Resumo

The importance of birds in the biological cycle of Neospora caninum is not clear. We report unsuccessful Neospora infection in chickens (Gallus gallus domesticus) using two isolates of N. caninum. In experiment \#1, 30 White Leghorn chickens were orally inoculated with viable N. caninum oocysts (NC-SP1 isolate, 200 oocysts per bird) via the crop at 21 days of age. Groups of three birds were euthanised at intervals of 7 days (a total of 9 weeks) and one group was challenged with the same oocyst dose at 37 days p.i. and observed for 11 weeks. Blood samples were collected weekly, and sera were tested using IFAT. Chicken tissues were collected for PCR, quantitative PCR and immunohistochemistry. Two dogs approximately 45 days of age were fed with tissues from chickens euthanised at 138 and 159 days p.i. The results indicated that the chickens were resistant to neosporosis as revealed by failure to seroconvert, to detect parasite DNA or N. caninum antigen by immunohistochemistry in inoculated bird tissues, and by no oocyst excretion by the dogs fed avian tissues. Similar results were obtained in experiment \#2, in which 34 1-week-old chickens were each s.c. inoculated with 100,000 tachyzoites of the NcWTDMn1 isolate of N. caninum. The chickens were euthanised on days 7, 15, 22, 28, 36 and 60 p.i. At necropsy, all tissues and serum from each bird were collected. All chickens remained asymptomatic, and N. caninum antigen was not detected by immunohistochemistry. Seven chickens euthanised at day 60 p.i. demonstrated low (1:25 dilution) levels of antibodies by using the Neospora agglutination test. Two 12-week-old dogs fed tissues pooled from 10 inoculated chickens euthanised at day 60 p.i. did not excrete N. caninum oocysts. This investigation indicates that chickens are resistant to experimental infection by N. caninum. (C) 2017 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 11/10636-4 - Estudo da infecção experimental oral com oocistos de Neospora caninum (isolados Nc-1 e Nc-Bahia) em galináceos (Gallus domesticus) jovens e adultos: resposta sorológica e parasitológica
• Beneficiário: Hilda Fátima de Jesus Pena
• Modalidade de apoio: Auxílio à Pesquisa - Regular