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Li Y, Zhou H, Li B, Li J, Shen Y, Jiang Y, Cui W, Tang L. Immunoprotection of FliBc chimeric fiber2 fusion proteins targeting dendritic cells against Fowl adenovirus serotype 4 infection. Poult Sci 2024; 103:103474. [PMID: 38387285 PMCID: PMC10899072 DOI: 10.1016/j.psj.2024.103474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/28/2023] [Accepted: 01/11/2024] [Indexed: 02/24/2024] Open
Abstract
Hepatitis-hydropericardium syndrome (HHS) is a highly fatal disease in chickens caused by the highly pathogenic fowl adenovirus serotype 4 (FAdV-4), which has severe economic consequences. The fiber2 protein exhibits excellent potential as a candidate for a subunit vaccination against FAdV-4. Despite having a high safety profile, subunit vaccines have low immunogenicity due to their lack of infectivity, which leads to low levels of immune response. As a vaccine adjuvant, Salmonella flagellin possesses the potential to augment the immunological response to vaccinations. Additionally, a crucial strategy for enhancing vaccine efficacy is efficient presentation of immune antigens to dendritic cells (DC) for targeted vaccination. In this study, we designed FAdV-4-fiber2 protein, and a recombinant protein called FliBc-fiber2-SP which based on FAdV-4-fiber2 protein, was generated using the gene sequence FliBc, which retains only the conserved sequence at the amino and carboxyl termini of the flagellin B subunit, and a short peptide SPHLHTSSPWER (SP), which targets chicken bone marrow-derived DC. They were separately administered via intramuscular injection to 14-day-old specific pathogen-free (SPF) chickens, and their immunogenicity was compared. At 21 d postvaccination (dpv), it was found that the FliBc-fiber2-SP recombinant protein elicited significantly higher levels of IgG antibodies and conferred a vaccine protection rate of up to 100% compared to its counterpart fiber2 protein. These results suggest that the DC-targeted peptide fusion strategy for flagellin chimeric antigen construction can effectively enhance the immune protective efficacy of antigen proteins.
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Affiliation(s)
- Yue Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 1550030, China
| | - Han Zhou
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 1550030, China; Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development, Harbin 150030, China
| | - Bolong Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 1550030, China
| | - Jiaxuan Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 1550030, China; Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development, Harbin 150030, China
| | - Yuanmeng Shen
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 1550030, China
| | - Yanping Jiang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 1550030, China; Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development, Harbin 150030, China
| | - Wen Cui
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 1550030, China; Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development, Harbin 150030, China
| | - Lijie Tang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 1550030, China; Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical Development, Harbin 150030, China.
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Jakab S, Bali K, Homonnay Z, Kaszab E, Ihász K, Fehér E, Mató T, Kiss I, Palya V, Bányai K. Genomic Epidemiology and Evolution of Fowl Adenovirus 1. Animals (Basel) 2023; 13:2819. [PMID: 37760219 PMCID: PMC10525556 DOI: 10.3390/ani13182819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/16/2023] [Accepted: 08/28/2023] [Indexed: 09/29/2023] Open
Abstract
Fowl adenovirus 1 (FAdV-1) is the main cause of gizzard erosion in chickens. Whole genome sequencing and sequence analyses of 32 FAdV-1 strains from a global collection provided evidence that multiple recombination events have occurred along the entire genome. In gene-wise phylogenies, only the adenoviral pol gene formed a tree topology that corresponded to whole genome-based phylogeny. Virus genetic features that were clearly connected to gizzard erosion were not identified in our analyses. However, some genome variants tended to be more frequently identified from birds with gizzard erosion and strains isolated from healthy birds or birds with non-specific pathologies tended to form common clusters in multiple gene phylogenies. Our data show that the genetic diversity is greater, and the evolutionary mechanisms are more complex within FAdV-1 than previously thought. The implications of these findings for viral pathogenesis and epidemiology await further investigation.
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Affiliation(s)
- Szilvia Jakab
- Veterinary Medical Research Institute, Hungária krt. 21, H-1143 Budapest, Hungary; (S.J.); (K.B.); (E.K.); (K.I.); (E.F.)
- National Laboratory for Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, Hungária krt. 21, H-1143 Budapest, Hungary
| | - Krisztina Bali
- Veterinary Medical Research Institute, Hungária krt. 21, H-1143 Budapest, Hungary; (S.J.); (K.B.); (E.K.); (K.I.); (E.F.)
- National Laboratory for Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, Hungária krt. 21, H-1143 Budapest, Hungary
| | - Zalán Homonnay
- Ceva-Phylaxia Ltd., Szállás u. 5, H-1107 Budapest, Hungary; (Z.H.); (T.M.); (I.K.); (V.P.)
| | - Eszter Kaszab
- Veterinary Medical Research Institute, Hungária krt. 21, H-1143 Budapest, Hungary; (S.J.); (K.B.); (E.K.); (K.I.); (E.F.)
- National Laboratory for Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, Hungária krt. 21, H-1143 Budapest, Hungary
| | - Katalin Ihász
- Veterinary Medical Research Institute, Hungária krt. 21, H-1143 Budapest, Hungary; (S.J.); (K.B.); (E.K.); (K.I.); (E.F.)
| | - Enikő Fehér
- Veterinary Medical Research Institute, Hungária krt. 21, H-1143 Budapest, Hungary; (S.J.); (K.B.); (E.K.); (K.I.); (E.F.)
- National Laboratory for Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, Hungária krt. 21, H-1143 Budapest, Hungary
| | - Tamás Mató
- Ceva-Phylaxia Ltd., Szállás u. 5, H-1107 Budapest, Hungary; (Z.H.); (T.M.); (I.K.); (V.P.)
| | - István Kiss
- Ceva-Phylaxia Ltd., Szállás u. 5, H-1107 Budapest, Hungary; (Z.H.); (T.M.); (I.K.); (V.P.)
| | - Vilmos Palya
- Ceva-Phylaxia Ltd., Szállás u. 5, H-1107 Budapest, Hungary; (Z.H.); (T.M.); (I.K.); (V.P.)
| | - Krisztián Bányai
- Veterinary Medical Research Institute, Hungária krt. 21, H-1143 Budapest, Hungary; (S.J.); (K.B.); (E.K.); (K.I.); (E.F.)
- National Laboratory for Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, Hungária krt. 21, H-1143 Budapest, Hungary
- Department of Pharmacology and Toxicology, University of Veterinary Medicine, István utca 2, H-1078 Budapest, Hungary
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Xie Z, Zhang J, Sun M, Zeng Q, Huang Y, Dong J, Li L, Huang S, Liao M. The first complete genome sequence and pathogenicity characterization of fowl adenovirus serotype 2 with inclusion body hepatitis and hydropericardium in China. Front Vet Sci 2022; 9:951554. [PMID: 36072393 PMCID: PMC9443503 DOI: 10.3389/fvets.2022.951554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
Since 2015, fowl adenovirus (FAdV) has been frequently reported worldwide, causing serious economic losses to the poultry industry. In this study, a FAdV-2, namely GX01, was isolated from liver samples of chickens with hepatitis and hydropericardium in Guangxi Province, China. The complete genome sequence of GX01 was determined about 43,663 base pairs (bp) with 53% G+C content. To our knowledge, this is the first FAdV-2 complete genome in China. There was a deleting fragment in ORF25 gene. Phylogenetic analysis based on the hexon loop-1 gene showed that GX01 is most closely related to FAdV-2 strain 685. Pathogenicity experiment of GX01 in 3-day-old and 10-day-old specific-pathogen-free chickens showed that although no mortality was observed within 21 days post infection (dpi), strain GX01 significantly inhibited weight gain of infected chickens. Moreover, FAdV-2 was still detectable in the anal swabs of infected chickens at 21 dpi. Necropsy analysis showed that the main lesions were observed in liver, heart, and spleen. Of note, hepatitis and hydropericardium were observed in the infected chickens. In addition, massive necrosis of lymphocyte was observed in spleen of infected 3-days-old chickens. We concluded that FAdV-2 strain GX01 is capable of causing hepatitis and hydropericardium, which will make serious impact on the growth of chickens. Our research lays a foundation to investigate the molecular epidemiology and etiology of FAdV.
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Affiliation(s)
- Zimin Xie
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry Diseases, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Ministry of Agriculture and Rural Affairs, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, China
- College of Life Science and Engineering, Foshan University, Foshan, China
| | - Junqin Zhang
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry Diseases, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Ministry of Agriculture and Rural Affairs, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, China
| | - Minhua Sun
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry Diseases, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Ministry of Agriculture and Rural Affairs, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, China
| | - Qinghang Zeng
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry Diseases, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Ministry of Agriculture and Rural Affairs, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, China
| | - Yunzhen Huang
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry Diseases, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Ministry of Agriculture and Rural Affairs, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, China
| | - Jiawen Dong
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry Diseases, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Ministry of Agriculture and Rural Affairs, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, China
| | - Linlin Li
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry Diseases, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Ministry of Agriculture and Rural Affairs, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, China
| | - Shujian Huang
- College of Life Science and Engineering, Foshan University, Foshan, China
- *Correspondence: Shujian Huang
| | - Ming Liao
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry Diseases, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Ministry of Agriculture and Rural Affairs, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong, China
- Guangdong Academy of Agricultural Sciences, Guangzhou, China
- Ming Liao
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Niczyporuk JS, Kozdruń W. Current epidemiological situation in the context of inclusion body hepatitis in poultry flocks in Poland. Virus Res 2022; 318:198825. [PMID: 35618076 DOI: 10.1016/j.virusres.2022.198825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/20/2022] [Accepted: 05/21/2022] [Indexed: 11/16/2022]
Abstract
The research has been undertaken to understand the spreading of adenovirus strains in Poland's poultry flocks in the last six years. One hundred and forty-nine herds suspected of infection with adenoviruses were tested and the presence of poultry adenoviruses was found in 86 studied herds which were about 57,71% of examined flocks. Thirty-eight (44.18%) strains were connected with the infection of inclusion body hepatitis, 11 (12.79%) strains were isolated from digestive system dysfunction, 33 (38.37%) strains had been obtained from the flocks with no symptomatic changes/behaviour, and four (4.65%) strains were obtained from flocks with the manifestation of depression. Sequencing analysis was based on Loop L1 region of the HVR1-4 fragment of the hexon gene. The adenovirus strains were classified into five species FAdV-A-E, belonging to the following eight serotypes: FAdV-1/A, FAdV-5/B, FAdV-3/10/C, FAdV-9/11/D, and FAdV-7/8a/E. The most common serotype in poultry turned out to be type/species FAdV-11/D, FAdV-5/B, and FAdV-7/8b/E while the least frequent was type/species FAdV-3/10/C (only four and two strains respectively of this types were isolated with the following range: FAdV-1/A 6 (6.97%), FAdV-5/B 24 (27,90%), FAdV-3/C 4 (4,65%), FAdV-10/C 2 (2,32%), FAdV-11/D 36 (41,86%), and FAdV-E 14 (16.27%). The understanding of genetic diversity, geographic distribution, and antigenic properties of fowl adenovirus strains (FAdVs) isolated in Poland have been evaluated.
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Affiliation(s)
- Jowita Samanta Niczyporuk
- Department of Poultry Disease of National Veterinary Research Institute, Partyzantów 57 Avenue, 24-100 Pulawy, Poland,.
| | - Wojciech Kozdruń
- Department of Poultry Disease of National Veterinary Research Institute, Partyzantów 57 Avenue, 24-100 Pulawy, Poland
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Tsiouris V, Mantzios T, Kiskinis K, Guérin JL, Croville G, Brellou GD, Apostolopoulou EP, Petridou EJ, Georgopoulou I. First Detection and Identification of FAdV-8b as the Causative Agent of an Outbreak of Inclusion Body Hepatitis in a Commercial Broiler Farm in Greece. Vet Sci 2022; 9:vetsci9040160. [PMID: 35448658 PMCID: PMC9027271 DOI: 10.3390/vetsci9040160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/11/2022] [Accepted: 03/21/2022] [Indexed: 02/05/2023] Open
Abstract
Inclusion body hepatitis (IBH) is an economically important disease of chickens, with a worldwide distribution, caused by Fowl Aviadenoviruses (FAdVs). Currently, the increased number of cases, the virulence of the isolate strains, as well as the lack of cross-species protection highlight that detailed in-field data are fundamental for the development of successful control strategies. This case report provides a detailed clinicopathological investigation of an unusual IBH outbreak in a commercial broiler farm in the region of Macedonia, Greece. The farm consisted of 64,000 birds, originated from the same breeder stock and placed in three different houses (Flock A–C). At 20 days of age, a sudden increase in daily mortality was recorded in Flock A. It is worth mentioning that, although all flocks were serologically (indirect ELISA) and molecularly (RT-PCR) positive for FAdV, the mortality rate, attributed to IBH, was much higher in Flock A compared to others. The clinical manifestation included non-specific symptoms such as depression, inappetence, yellowish mucoid diarrhea, and lack of uniformity. At necropsy, typically, enlarged, pale, and friable livers were dominant, while sporadically lesions were recorded in the pancreas, kidneys, skeletal muscles, and lymphoid organs. The histopathological examination of liver samples showed multifocal inflammation, necrosis, and the presence of basophilic/ eosinophilic inclusion bodies in hepatocytes. In addition, the loss of the architecture of pancreatic lobules and the presence of fibrosis and foci of mononuclear cell aggregates were suggestive of chronic pancreatic inflammation. PCR analysis confirmed the presence of FAdV, belonging to species E, serotype FAdV-8b. Performance and financial calculations revealed that IBH increased Feed Conversion Ratio (FCR), feed cost/chick as well as feed cost/kg live weight, whereas the Livability (%) and the European Production Efficiency Factor (EPEF) were decreased in the most severely affected flocks (Flock A). This study is the first report of the detection and identification of FAdV serotypes associated with IBH in commercial broiler flocks in Greece. However, there is still a lack of information about the circulating FAdV serotypes in the country, and therefore epidemiological studies are needed to establish control strategies for IBH.
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Affiliation(s)
- Vasileios Tsiouris
- Unit of Avian Medicine, Clinic of Farm Animals, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54627 Thessaloniki, Greece; (V.T.); (K.K.); (I.G.)
| | - Tilemachos Mantzios
- Unit of Avian Medicine, Clinic of Farm Animals, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54627 Thessaloniki, Greece; (V.T.); (K.K.); (I.G.)
- Correspondence: ; Tel.: +30-2310994551
| | - Konstantinos Kiskinis
- Unit of Avian Medicine, Clinic of Farm Animals, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54627 Thessaloniki, Greece; (V.T.); (K.K.); (I.G.)
| | - Jean-Luc Guérin
- IHAP, Université de Toulouse, INRAE, ENVT, 31300 Toulouse, France; (J.-L.G.); (G.C.)
| | - Guillaume Croville
- IHAP, Université de Toulouse, INRAE, ENVT, 31300 Toulouse, France; (J.-L.G.); (G.C.)
| | - Georgia D. Brellou
- Laboratory of Pathology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54627 Thessaloniki, Greece; (G.D.B.); (E.P.A.)
| | - Emmanouela P. Apostolopoulou
- Laboratory of Pathology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54627 Thessaloniki, Greece; (G.D.B.); (E.P.A.)
| | - Evanthia J. Petridou
- Laboratory of Microbiology and Infectious Diseases, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
| | - Ioanna Georgopoulou
- Unit of Avian Medicine, Clinic of Farm Animals, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54627 Thessaloniki, Greece; (V.T.); (K.K.); (I.G.)
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Species Fowl aviadenovirus B Consists of a Single Serotype despite Genetic Distance of FAdV-5 Isolates. Viruses 2022; 14:v14020248. [PMID: 35215844 PMCID: PMC8880664 DOI: 10.3390/v14020248] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/19/2022] [Accepted: 01/21/2022] [Indexed: 01/08/2023] Open
Abstract
Fowl adenoviruses (FAdVs) are infectious agents, mainly of chickens, which cause economic losses to the poultry industry. Only a single serotype, namely FAdV-5, constitutes the species Fowl aviadenovirus B (FAdV-B); however, recently, phylogenetic analyses have identified divergent strains of the species, implicating a more complex scenario and possibly a novel serotype. Therefore, field isolates of the species were collected to investigate the contemporary diversification within FAdV-B, including traditional serotyping. Full genomes of fourteen FAdV-B strains were sequenced and four strains, possessing discriminatory mutations in the antigenic domains, were compared using virus cross-neutralization. Essentially, strains with identical antigenic signatures to that of the first described divergent strain were found in the complete new dataset. While chicken antiserum against FAdV-5 reference strain 340 could not neutralize any of the newly isolated viruses, low homologous/heterologous titer ratios were measured reciprocally. Although they argue against a new serotype, our results indicate the emergence of escape variants in FAdV-B. Charge-influencing amino acid substitutions accounted for only a few mutations between the strains; still, these enabled one-way cross-neutralization only. These findings underline the continued merit of the cross-neutralization test as the gold standard for serotyping, complementary to advancing sequence data, and provide a snapshot of the actual diversity and evolution of species FAdV-B.
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A 10-Year Retrospective Study of Inclusion Body Hepatitis in Meat-Type Chickens in Spain (2011-2021). Viruses 2021; 13:v13112170. [PMID: 34834976 PMCID: PMC8617850 DOI: 10.3390/v13112170] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 10/25/2021] [Accepted: 10/25/2021] [Indexed: 12/28/2022] Open
Abstract
A surge in fowl adenovirus (FAdV) causing inclusion body hepatitis (IBH) outbreaks has occurred in several countries in the last two decades. In Spain, a sharp increase in case numbers in broilers and broiler breeder pullets arose since 2011, which prompted the vaccination of breeders in some regions. Our retrospective study of IBH cases in Spain from 2011 to 2021 revealed that most cases were reported in broilers (92.21%) and were caused by serotypes FAdV-8b and -11, while cases in broiler breeder pullets were caused by serotypes FAdV-2, -11, and -8b. Vertical transmission was the main route of infection, although horizontal transmission likely happened in some broiler cases. Despite the inconsistent and heterogeneous use of vaccines among regions and over time, the number of cases mirrored the use of vaccines in the country. While IBH outbreaks were recorded year-long, significantly more cases occurred during the cooler and rainier months. The geographic distribution suggested a widespread incidence of IBH and revealed the importance of a highly integrated system. Our findings contribute to a better understanding of FAdV infection dynamics under field conditions and reiterate the importance of surveillance, serological monitoring of breeders, and vaccination of breeders against circulating serotypes to protect progenies.
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Immunogenicity of Novel Live Vaccine Based on an Artificial rHN20 Strain against Emerging Fowl Adenovirus 4. Viruses 2021; 13:v13112153. [PMID: 34834960 PMCID: PMC8622778 DOI: 10.3390/v13112153] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 12/23/2022] Open
Abstract
In recent years, hepatitis-hydropericardium syndrome (HHS), caused by novel fowl adenovirus 4 (FAdV-4), has caused serious economic losses to the poultry industry. Vaccines are important for preventing and controlling HHS. Current FAdV-4 vaccine research and development are mainly focuses on inactivated vaccines and relatively fewer live vaccines. We previously demonstrated that the hexon gene is the key gene responsible for the high pathogenicity of FAdV-4 and constructed a non-pathogenic chimeric virus rHN20 strain based on the emerging FAdV-4. In this study, the immunogenicity of artificially rescued rHN20 was evaluated in chickens using different routes and doses as a live vaccine. The live rHN20 vaccine induced high titers of neutralizing antibodies against FAdV-4 and fully protected the immunized chickens against a lethal dose of FAdV-4. Furthermore, immunized chickens showed no clinical symptoms or histopathological changes in the FAdV-4-targeted liver, and the viral load in the tissues of immunized chickens was significantly lower than that of chickens in the challenge control group. Collectively, the live rHN20 vaccine effectively protected our sample against FAdV-4 infection and can be considered a live vaccine candidate for preventing HHS in the poultry industry.
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