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Gerber PF, Spatz S, Gray P, Alfirevich S, Walkden-Brown SW. Circulation and Molecular Characterization of Hemorrhagic Enteritis Virus in Commercial Turkey and Meat Chicken Flocks in Australia. Avian Dis 2022; 66:53-59. [DOI: 10.1637/21-00095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 11/02/2021] [Indexed: 11/05/2022]
Affiliation(s)
- Priscilla F. Gerber
- Animal Science, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia
| | - Stephen Spatz
- U.S. Department of Agriculture, Agricultural Research Service, U.S. National Poultry Research Center, Athens, GA 30605
| | - Peter Gray
- Inghams Enterprises P/L, Morisset, New South Wales 2264, Australia
| | | | - Stephen W. Walkden-Brown
- Animal Science, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia
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Hoang P, Gerber PF, Reynolds P, McMillan M, Gray P, Walkden-Brown SW. Preliminary testing in turkeys of the safety and efficacy of a putative haemorrhagic enteritis virus vaccine. Aust Vet J 2019; 97:323-332. [PMID: 31328258 DOI: 10.1111/avj.12841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 04/08/2019] [Accepted: 05/18/2019] [Indexed: 11/28/2022]
Abstract
Haemorrhagic enteritis virus (HEV) causes clinical haemorrhagic enteritis in young poults and/or subclinical immunosuppression which is often associated with colibacillosis. This disease is controlled with live vaccines worldwide, however, importation of HEV vaccines or cells that support HEV propagation are not permitted in Australia. A major experiment in isolators was conducted to test the safety and efficacy of a putative HEV vaccine. The study had a factorial design with four factors namely vaccination age (28 and 42 days of age), vaccine dose (0, 105 , 106 , 107 genomic copies of HEV vaccine), challenge with HEV (yes, no) and vaccination-challenge interval (7, 21 or 42 days). A total of 315 poults were used providing 6-8 birds per treatment combination. Turkey growth rate, mortality, pathological findings, anti-HEV antibodies and viral load were examined. Vaccination lead to significant increases in anti HEV antibody over the following 2-4 weeks. Overall, vaccination with 106 and 107 was protective against increase in relative splenic weight and splenic viral load in challenged birds. Clinical haemorrhagic enteritis was not induced by any treatment but there was an increased incidence of airsacculitis in groups receiving either HEV vaccine or challenge virus compared to the negative control birds (25.8-29.3% vs. 9.4%, P < 0.05). Growth rate, mortality and relative bursal weight were unaffected by vaccination. This laboratory level study indicates that the putative vaccine is safe and likely to be efficacious, but may cause elevated levels of airsacculitis. These findings require confirmation in larger scale field trials.
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Affiliation(s)
- Phuong Hoang
- Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia.,Faculty of 'Chan Nuoi Thu Y', Tay Nguyen University, 567 Le Duan Street, Buon Ma Thuot City, DakLak Province, Vietnam
| | - Priscilla F Gerber
- Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia
| | - Paul Reynolds
- Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia
| | - Mary McMillan
- Molecular and Cellular Biology, School of Science and Technology, University of New England, Armidale, NSW, 2351, Australia
| | - Peter Gray
- Inghams Enterprises P/L, Morrisset, NSW, 2264
| | - Stephen W Walkden-Brown
- Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia
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Gerber PF, Hossain MF, Reynolds P, Hoang P, Burgess SK, Renz K, McMillan M, Katz ME, Walkden-Brown SW. Propagation of an Avirulent Turkey Hemorrhagic Enteritis Virus Isolate in Chickens. Avian Dis 2018; 62:6-13. [PMID: 29620462 DOI: 10.1637/11762-102317-reg.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A series of studies were undertaken to optimize the propagation of hemorrhagic enteritis virus (HEV) in specific-pathogen-free (SPF) chickens. A total of 562 SPF chickens were orally inoculated with an Australian avirulent HEV isolate of turkey origin at 9, 14, 21, or 28 days of age with 5, 6, 7, or 8 log 10 genomic copies (GC), while 102 chickens served as uninfected controls. No clinical signs were observed in infected chickens. There was an inoculum-dose-dependent increase in the relative spleen and liver weight ( P < 0.01). Relative spleen weight 7 days post-HEV inoculation was up to 85% higher in chickens that were inoculated with 6 to 7 GC compared with controls, with no further increase at higher doses. Relative liver weight increased up to 14% in chickens inoculated with 6 GC, with no further increase. Birds inoculated with a 7 GC dose had a higher frequency of HEV DNA-positive birds (77% to 86%) than birds inoculated with lower doses (33% to 59%; P < 0.01). The most efficient dose for live passage propagation was 7 GC inoculated in 9-to-14-day-old birds, yielding an infection rate of 81%. Livers and spleens from infected birds at all doses were processed to produce a putative vaccine with a final GC recovery in the vaccine material of 8.6 GC/bird. In summary, HEV of turkey origin can be readily propagated in SPF chickens, and conditions to maximize viral retrieval were established.
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Affiliation(s)
- Priscilla F Gerber
- A Animal Science, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia
| | - Mohammad F Hossain
- A Animal Science, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia
| | - Paul Reynolds
- A Animal Science, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia
| | - Phuong Hoang
- A Animal Science, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia
| | - Susan K Burgess
- A Animal Science, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia
| | - Katrin Renz
- A Animal Science, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia
| | - Mary McMillan
- B Molecular and Cellular Biology, School of Science and Technology, University of New England, Armidale, New South Wales 2351, Australia
| | - Margaret E Katz
- B Molecular and Cellular Biology, School of Science and Technology, University of New England, Armidale, New South Wales 2351, Australia
| | - Stephen W Walkden-Brown
- A Animal Science, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia
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Chandra R, Kumar A. Haemorrhagic enteritis of turkeys and related infections of pheasants and domestic fowl: a review. WORLD POULTRY SCI J 1998. [DOI: 10.1079/wps19980017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Rajesh Chandra
- Department of Veterinary Microbiology and College of Veterinary Sciences, G.B. Pant University of Agriculture and Technology, Pantnagar 263145, U.S. Nagar, U.P., India
| | - Ashok Kumar
- Department of Veterinary Public Health, College of Veterinary Sciences, G.B. Pant University of Agriculture and Technology, Pantnagar 263145, U.S. Nagar, U.P., India
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