Synergy between avian pneumovirus and Ornithobacterium rhinotracheale in turkeys

The purpose of this study was to assess the possible synergism between Ornithobacterium rhinotracheale (ORT) and avian pneumovirus (APV), inoculated into turkeys via the natural route, for the reproduction of respiratory disease. Three-week-old specific pathogen free turkeys were inoculated oculonasally with either APV subtype A, ORT or both agents using two different time intervals (3 and 5 days) between APV and ORT. The birds were observed clinically on a daily basis and swabbed intratracheally at short, regular intervals. They were killed at 1, 3, 5, 8 and 15 days post single or dual inoculation and examined for gross lesions at necropsy. Samples of the turbinates, trachea, lungs, air sacs, heart, pericardium and liver were taken for bacteriological and/or histological examination. Combined APV/ORT infections resulted in overt clinical signs and a longer persistence of ORT in the respiratory tract and aggravated the macroscopic and histological lesions in comparison with the groups given single infections. In all ORT-challenged turkeys, ORT was isolated from the turbinates, trachea and lungs, but in turkeys infected with both agents ORT was frequently found in the air sacs and on a single occasion in the heart and pericardium. The time interval between APV and ORT inoculation did not have a significant effect on the outcome of the dual infection. A conspicuous important feature was the attachment of ORT to the cilia of the epithelium of the turbinates and trachea of both ORT-infected and APV/ORT-infected birds. In conclusion, the results show that ORT is able to adhere to and colonize the respiratory tract but, under the circumstances used in this study, is not capable of inducing respiratory disease without viral priming.

[1]  H. Nauwynck,et al.  Key role of Chlamydophila psittaci on Belgian turkey farms in association with other respiratory pathogens. , 2005, Veterinary microbiology.

[2]  J. Darbyshire,et al.  The use of chicken tracheal organ cultures for the isolation and assay of avian infectious bronchitis virus , 2005, Archives of Virology.

[3]  S. Noll,et al.  Effects of Bacterial Coinfection on the Pathogenesis of Avian Pneumovirus Infection in Turkeys , 2004, Avian diseases.

[4]  P. Navarrete,et al.  Identification and Characterization of Ornithobacterium rhinotracheale Isolates from Mexico , 2002, Avian diseases.

[5]  A. Musa,et al.  Studies on the Bacterial Etiology of Airsacculitis of Broilers in Northern and Middle Jordan with Special Reference to Escherichia coli, Ornithobacterium rhinotracheale, and Bordetella avium , 2002, Avian diseases.

[6]  S. Noll,et al.  Pathogenesis of Avian Pneumovirus Infection in Turkeys , 2002, Veterinary pathology.

[7]  H. Nauwynck,et al.  The clinical, pathological and microbiological outcome of an Escherichia coli O2:K1 infection in avian pneumovirus infected turkeys. , 2001, Veterinary microbiology.

[8]  E. Gruys,et al.  Increased condemnation of broilers associated with Ornithobacterium rhinotracheale , 2000, Veterinary Record.

[9]  T. Fabri,et al.  Ornithobacterium rhinotracheale, a Primary Pathogen in Broilers , 2000 .

[10]  H. Nauwynck,et al.  Comparative pathogenesis of a subtype A with a subtype B avian pneumovirus in turkeys. , 1999, Avian pathology : journal of the W.V.P.A.

[11]  H. Hafez,et al.  Ornithobacterium rhinotracheale: A review. , 1999, Avian pathology : journal of the W.V.P.A.

[12]  D. Goovaerts,et al.  Immunohistochemical and serological investigation of experimental Ornithobacterium rhinotracheale infection in chickens. , 1999, Avian pathology : journal of the W.V.P.A.

[13]  K. Nagaraja,et al.  Tissue distribution of Ornithobacterium rhinotracheale in experimentally infected turkeys , 1998, Veterinary Record.

[14]  M. Jacques,et al.  Adhesin-receptor interactions in Pasteurellaceae. , 1998, FEMS microbiology reviews.

[15]  H. Nauwynck,et al.  Infections and reinfections with avian pneumovirus subtype A and B on Belgian turkey farms and relation to respiratory problems. , 1998, Zentralblatt fur Veterinarmedizin. Reihe B. Journal of veterinary medicine. Series B.

[16]  K. Nagaraja,et al.  Ornithobacterium rhinotracheale infection in turkeys: experimental reproduction of the disease. , 1998, Avian diseases.

[17]  K. Nagaraja,et al.  Isolation and identification of Ornithobacterium rhinotracheale from commercial turkey flocks in the upper midwest. , 1998, Avian diseases.

[18]  H. Shivaprasad,et al.  Ornithobacterium rhinotracheale infection in turkey breeders. , 1996, Avian diseases.

[19]  D. Goovaerts,et al.  Experimental infection in turkeys and chickens with Ornithobacterium rhinotracheale. , 1996, Avian diseases.

[20]  B. Gummow,et al.  Pathogenicity differences between South African isolates of Ornithobacterium rhinotracheale. , 1996, The Onderstepoort journal of veterinary research.

[21]  H. Salisch,et al.  Pathogenicity of Ornithobacterium rhinotracheale for turkey poults under experimental conditions , 1996, Veterinary Record.

[22]  A. Travers.  Concomitant Ornithobacterium rhinotracheale and Newcastle disease infection in broilers in South Africa. , 1996, Avian diseases.

[23]  R. Reece,et al.  Color atlas of avian histopathology , 1996 .

[24]  J. Bongers,et al.  [Respiratory problems, growth retardation and arthritis in turkeys and broilers caused by a Pasteurella-like organism: Ornithobacterium rhinotracheale or 'Taxon 28']. , 1994, Tijdschrift voor diergeneeskunde.

[25]  D. Kelly,et al.  Demonstration of a candidate virus for turkey rhinotracheitis in experimentally inoculated turkeys , 1986, Veterinary Record.