Virus-induced immunosuppression in turkeys (&lt;i&gt;Meleagris gallopavo&lt;/i&gt;): A review

Kaboudi, Khaled

doi:10.4314/ovj.v9i4.13

Cited by 7 publications

(4 citation statements)

References 97 publications

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“…Following analysis of previously published virulence factors ORF1, E3, and Fib knob [ 40 ] as well as the hexon gene, only two out of nine analyzed sequences were deemed tissue culture vaccine-like strains (one sequence obtained from a vaccinated flock, and the other one from a non-vaccinated flock); while seven out of nine were classified as field strain (three sequences obtained from vaccinated flocks, and the other four from non-vaccinated flocks) ( Table 3 ). Although all flocks present in this study were suspected to have an immunosuppression component, due to a perceived increased susceptibility to secondary bacterial infections [ 11 ], it is interesting to note that out of four sequences obtained from HE-vaccinated flocks and with secondary bacterial infections (e.g., cellulitis, systemic bacterial infection, and gangrenous dermatitis) (18-0430; 18-0665; 18-0943; and 18-0988) ( Table 1 ), three were classified as HEV field virus with no recovery of any vaccine sequence. Recovery of a vaccine sequence was expected after successful HE vaccination in these farms as vaccine is expected to reduce clinical signs, but not virus infection ( Table 3 ).…”

Section: Discussionmentioning

confidence: 99%

“…The disease has two presentations: (1) clinical disease consisting of depression, gastrointestinal hemorrhages, and transient immunosuppression followed by increased mortality (up to 80% for highly virulent strains due to blood loss and secondary infection with opportunists like Escherichia coli ) [ 6 , 7 , 8 ]; and (2) subclinical infection, consisting in immunosuppression and causing economical losses because of secondary bacterial infection, especially from Escherichia coli , and processing plant condemnations [ 7 , 9 , 10 ]. The immunosuppression caused by the subclinical infection increases the birds susceptibility to secondary bacterial infections which poses a problem for the judicious antibiotic use in farm animals, both being important problems for the turkey industry [ 11 ].…”

Section: Introductionmentioning

confidence: 99%

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Molecular Characterization of Hemorrhagic Enteritis Virus (HEV) Obtained from Clinical Samples in Western Canada 2017–2018

Palomino-Tapia

Mitevski²,

Inglis³

et al. 2020

Viruses

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Hemorrhagic enteritis virus (HEV) is an immunosuppressive adenovirus that causes an acute clinical disease characterized by hemorrhagic gastroenteritis in 4-week-old turkeys and older. Recurrent incidence of secondary infections (e.g., systemic bacterial infections, cellulitis, and elevated mortality), may be associated with the presence of field-type HEV in Canadian turkey farms. We speculate that field-type HEV and vaccine/vaccine-like strains can be differentiated through analysis of the viral genomes, hexon genes, and the specific virulence factors (e.g., ORF1, E3, and fib knob domain). Nine out of sixteen spleens obtained from cases suspected of immunosuppression by HEV were analyzed. The limited data obtained showed that: (1) field-type HEV circulates in many non-vaccinated western Canadian flocks; (2) field-type HEV circulates in vaccinated flocks with increased recurrent bacterial infections; and (3) the existence of novel point mutations in hexon, ORF1, E3, and specially fib knob domains. This is the first publication showing the circulation of wild-type HEV in HEV-vaccinated flocks in Western Canada, and the usefulness of a novel procedure that allows whole genome sequencing of HEV directly from spleens, without passaging in cell culture or passaging in vivo. Further studies focusing more samples are required to confirm our observations and investigate possible vaccination failure.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Molecular Characterization of Hemorrhagic Enteritis Virus (HEV) Obtained from Clinical Samples in Western Canada 2017–2018

Palomino-Tapia

Mitevski²,

Inglis³

et al. 2020

Viruses

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“…The aMPV has a wide global distribution, essentially where there are poultry production or migratory bird routes the virus can be identified, but what changes is the prevalence of subtypes A, B, C and D, in addition to the two new subtypes described: (a) subtypes A and B are likely to be found in Europe, Brazil and the African continent [ 39 ]; (b) the C subtype has been identified in the United States, Canada, China, France and recently in South Korea [ 40 , 41 , 42 , 43 , 44 , 45 ]; and (c) the D subtype was only reported in France [ 39 ] and the two new subtypes were found in the United States and Canada [ 45 ]. Today, the most prevalent subtype in the world is B [ 22 , 46 ].…”

Section: Discovery and Distribution Of Avian Metapneumovirus (Ampv)mentioning

confidence: 99%

Trends and Challenges in the Surveillance and Control of Avian Metapneumovirus

Salles,

Pilati,

Muniz

et al. 2023

Viruses

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Among the respiratory pathogens of birds, the Avian Metapneumovirus (aMPV) is one of the most relevant, as it is responsible for causing infections of the upper respiratory tract and may induce respiratory syndromes. aMPV is capable of affecting the reproductive system of birds, directly impacting shell quality and decreasing egg production. Consequently, this infection can cause disorders related to animal welfare and zootechnical losses. The first cases of respiratory syndromes caused by aMPV were described in the 1970s, and today six subtypes (A, B, C, D, and two more new subtypes) have been identified and are widespread in all chicken and turkey-producing countries in the world, causing enormous economic losses for the poultry industry. Conventionally, immunological techniques are used to demonstrate aMPV infection in poultry, however, the identification of aMPV through molecular techniques helped in establishing the traceability of the virus. This review compiles data on the main aMPV subtypes present in different countries; aMPV and bacteria co-infection; vaccination against aMPV and viral selective pressure, highlighting the strategies used to prevent and control respiratory disease; and addresses tools for viral diagnosis and virus genome studies aiming at improving and streamlining pathogen detection and corroborating the development of new vaccines that can effectively protect herds, preventing viral escapes.

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“…On the frontline of the measures to mitigate the spread of avian diseases among turkey birds is the need to select disease resistance strains for breeding. Genetic resistance, as an intrinsic property, has been explored to select natural resistant poultry strain [20]. Selection of disease resistance strains in conjunction with other positively correlated economic traits for breeding enhance vigour in offspring and creation of pure breeds with important traits that guarantee the farmer's gains.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the response of Turkey strains to Salmonella and Newcastle vaccines

Ikpeme

2021

ARRB

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This research work was carried out to evaluate the immune response of 3 turkey strains to salmonella and Newcastle vaccines measured via antibody titre. The study deployed a total of 120 poults (40 black, 40 white and 40 lavender) strains. To ascertain the initial antibody titre of all the birds, blood samples were obtained from their wing veins immediately after acclimatization for salmonella and Newcastle antibody titre. The test for salmonella and Newcastle antibody titre responses of the birds were performed using widal and haemagglutination inhibition (HI), respectively. The birds were divided into two broad groups tagged as A and B, which represented Salmonella and Newcastle vaccines, respectively. Each group had 3 sub-groups denoting the 3 strains of turkey used for the study. After vaccination, blood samples were collected from all the birds at 3 and 5 days for laboratory assessment of antibody titre response. The results showed that there was significant increase (p<0.05) in the antibody titre response of all the turkey strains after vaccination. Results obtained on the time of exposure of the birds to vaccine revealed that higher antibody titre values were obtained from the black and white turkey strains at 3 days than at 5 days after administration of Newcastle vaccine, except in the lavender strain, which had higher titre value at 5 days after Newcastle vaccination. Following administration of salmonella vaccine, black and lavender strains had statistically higher antibody titre response (2.03 and 2.10 mean loge widal, respectively) than white strain (1.86 mean loge widal). Similarly, the black strain also had higher antibody titre value when Newcastle vaccine was administered (2.35 mean loge HI) followed by lavender (1.99 mean loge HI) and white strain (1.71 mean loge HI). Black strains showed more antibody titre response and by implication, stronger immunity to Salmonella and Newcastle vaccines. More importantly, the differential response of the 3 turkey strains to vaccine could give turkey breeders the choice of selection of turkey breeds for disease resistance breeding.

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Virus-induced immunosuppression in turkeys (<i>Meleagris gallopavo</i>): A review

Cited by 7 publications

References 97 publications

Molecular Characterization of Hemorrhagic Enteritis Virus (HEV) Obtained from Clinical Samples in Western Canada 2017–2018

Molecular Characterization of Hemorrhagic Enteritis Virus (HEV) Obtained from Clinical Samples in Western Canada 2017–2018

Trends and Challenges in the Surveillance and Control of Avian Metapneumovirus

Evaluation of the response of Turkey strains to Salmonella and Newcastle vaccines

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