Epidemics and Pathogenesis of Different IBDV Strains: History
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Contributor:
Hui Gao
,
Yongqiang Wang
,
Li Gao
,
Shijun J. Zheng

Infectious bursal disease virus (IBDV) is an immunosuppressive pathogen causing enormous economic losses to the poultry industry across the globe. As a double-stranded RNA virus, IBDV undergoes genetic mutation or recombination in replication during circulation among flocks, leading to the generation and spread of variant or recombinant strains. 

  • infectious bursal disease virus (IBDV)
  • genetic evolutionary typing
  • viral genome diversity

1. Classical IBDV (cIBDV)

In 1957, the original outbreak of IBD occurred in the area of Gumboro, Delaware, USA, where researchers observed a high rate of disease occurrence in chicks [1]. Early symptoms of IBD include diarrhea, loss of appetite, weakness, and even death [1]. The main target organ of the virus is the bursa of Fabricius (BF) of 3–6-week-old chicks, which is characterized by enlarged or hemorrhagic bursa during the first four days, followed by bursal atrophy later in the course of the disease [2][3][4]. The infection eventually leads to lymphocyte failure and destruction of the bursa, which is the main feature of IBD pathogenesis [5][6]. In classical epidemic situations, mortality in diseased chickens may range between 1% and 50%, with significant effects on both broilers and laying hens [2]. In addition to mortality, IBDV also has an immunosuppressive effect, which affects the host's immune response and the efficacy of other vaccinations [2][4][7]. The virus genome consists of two segments of RNAase-resistant, double-stranded RNAs [8]. The complete terminal sequences of IBDV genomic dsRNA have been identified, indicating that different RNA structures may have an impact on the ability of the virus to replicate [9]. As more complete genomic information on IBDV has become available, the correlation between genetic and pathogenic phenotypes among different strains of IBDV could be more precisely assessed [10][11][12][13][14][15].

2. Variant IBDV (varIBDV)

In the late 1980s, it was first reported that IBDV variants were identified by virus neutralization tests as serotypeI IBDV with significant antigenic differences from classical strains [16][17]. These antigenically altered strains were collectively referred to as variants IBDV to distinguish them from previous classical IBDV isolates [1][18]. Initially, the variant IBDV-infected chickens were characterized by little or no mortality and no obvious clinical signs, but their bursa and spleen were damaged [19][20][21]. Subsequent studies have shown that amino acid mutations in the hypervariable region (HVR, nt 616–1050, aa 206–350) of VP2 are the major cause of IBDV variants [22][23][24]. The VP2 hypervariable region includes many amino acid residues exposed on the protein surface, and mutations in these residues can lead to a variation in the antigenicity of VP2, allowing the variant to escape from the neutralizing antibodies produced by vaccination against the cIBDV [21][24]. This phenomenon is known as antigenic drift and is the primary reason for antigenic diversity [22][25]. Several mutations in the specific residues (222 T, 249 K, 254 S, 286 I, and 318 D) in the HVR may cause antigenic drift [26][27].

3. Very Virulent IBDV (vvIBDV)

At the time the variant IBDV was identified in North America, very virulent IBDV (vvIBDV) emerged in Europe [28][29]. In contrast to the variant strains, vvIBDV typically causes high morbidity and mortality in SPF chickens, resulting in mortality of 50–100%, along with typical signs and lesions. Importantly, vvIBDV can establish infection in the presence of maternal antibodies to the classical strain and cause lesions in immune organs other than the bursa [3][30]. As a highly transmissible virus, vvIBDV has spread rapidly throughout the world, causing significant economic losses to the poultry industry [14][31][32][33][34][35]. However, the emergence of vvIBDV promoted scientific research on the pathogenicity of IBDV infection.
Genetic studies revealed that the emergence of the vvIBDV strains was due to the reassortment of genetic segments, specifically the reassortment of the mutated segment A with the segment B of unknown origin, resulting in a sudden increase in the pathogenicity of the virus [36]. Residues 222 A, 242 I, 256 I, 294 I, and 299 S of the vvIBDV segment A are conserved compared to other strains of IBDV and serve as markers of pathogenicity [30][37][38]. In addition, residues 253 and 284 of VP2 are proposed to be the determinants of cell tropism and major contributors to IBDV virulence [39][40][41]. Phylogenetic analysis has shown that segment B of vvIBDV is distinct and highly conserved [26][36][42]. Additional studies have confirmed that both genomic segments contribute to the high virulence of vvIBDV [43][44][45][46][47]. As the efforts in exploring vvIBDV continue, more critical residues that may be involved in the pathogenicity of the virus have been identified [48][49][50].

4. Novel Variant IBDV (nVarIBDV)

Since 2015, China has experienced an outbreak of the novel variant IBDV (nVarIBDV) [51]. These isolated strains have distinct subclusters, indicating genetic evolution in both segments A and B of the viral genome, which rarely occurred in China before [52][53][54][55]. While the vvIBDV strain has historically been the most prevalent with low variability in field transmission [11][31], the recent emergence of nVarIBDV outbreaks in other Asian countries such as Japan [56], South Korea [57], and Malaysia [58] are of concern. It was reported that nVarIBDV does not cause severe clinical signs but causes irreversible damage to the immune organs of chickens, including bursal lesions, spleen swelling and atrophy, and long-term immunosuppression, to a greater extent than the previous varIBDV [51][59][60]. In addition, the new strains can break through the immune protection provided by existing vvIBDV vaccines [57][61][62].
The novel variant spectrum of IBDV strains exhibits significant genetic differences from previously reported IBDV strains. The strains contain multiple amino acid substitutions, with VP2 having typical residues similar to varIBDV (222 T, 249 K, 286 I, and 318 D) [26], as well as other residues such as 221 K, 252 I, and 299 S, and VP1 containing 147 D and 508 K [51]. Although the same amino acid differences have been reported in other studies [63], the relationship between these amino acid substitutions and the antigenicity and pathogenicity of the strains has not been fully investigated. Therefore, further investigations into novel variant IBDV strains are needed to better understand the epidemics of currently circulating IBDV strains.

5. Other Strain Types of IBDV

There are several other strain types of IBDV, including attenuated, reassortant, and recombinant strains. Attenuated strains usually refer to those attenuated live vaccine strains made especially for the control of cIBDV or vvIBDV infection and are classified as mild, intermediate, or intermediate-plus based on their attenuation [3]. The immunization of chicks with attenuated vaccine strains has become the primary defense against IBD in young chickens. Although attenuated strains are generally not lethal to chickens, intermediate and intermediate plus attenuated strains can cause varying degrees of bursal damage in vaccinated chickens [64]. However, due to the widespread use of live vaccines, the spread of different strain types among flocks in recent years has led to the increasing emergence of reassortant and recombinant strains of IBDV, such as strains with segment A of vvIBDV and segment B of attenuated strains [47][65][66], segment A of vvIBDV and segment B of serotypeII [46], and segment A of vaccine strains and segment B of vvIBDV [67][68], etc. Homologous recombination between different strains of IBDV has also been reported [26][69][70][71]. Recombination and reassortment between different strains pose new challenges to the prevention and control of IBD and require continued efforts to investigate the genetics and epidemics of IBDV.

This entry is adapted from the peer-reviewed paper 10.3390/ijms24098255

References

  1. Cosgrove, A. An apparently new disease of chickens: Avian nephrosis. Avian Dis. 1962, 6, 385–389.
  2. Müller, H.; Islam, M.R.; Raue, R. Research on infectious bursal disease—The past, the present and the future. Vet. Microbiol. 2003, 97, 153–165.
  3. Eterradossi, N.; Saif, Y. Infectious Bursal Disease (Gumboro Disease), Chapter 3.3.12. OIE Terrestrial Manual. Available online: http://www.oie.int/en/standard-setting/terrestrial-manual/access-online/ (accessed on 1 February 2023).
  4. Sharma, J.M.; Kim, I.J.; Rautenschlein, S.; Yeh, H.Y. Infectious bursal disease virus of chickens: Pathogenesis and immunosuppression. Dev. Comp. Immunol. 2000, 24, 223–235.
  5. Becht, H. Infectious Bursal Disease Virus. In Current Topics in Microbiology and Immunology; Springer: Berlin/Heidelberg, Germany, 1980; pp. 107–121. ISBN 978-3-642-67717-5.
  6. Vasconcelos, A.C.; Lam, K.M. Apoptosis induced by infectious bursal disease virus. J. Gen. Virol. 1994, 75, 1803–1806.
  7. Aricibasi, M.; Jung, A.; Heller, E.D.; Rautenschlein, S. Differences in genetic background influence the induction of innate and acquired immune responses in chickens depending on the virulence of the infecting infectious bursal disease virus (IBDV) strain. Vet. Immunol. Immunopathol. 2010, 135, 79–92.
  8. Müller, H.; Scholtissek, C.; Becht, H. The genome of infectious bursal disease virus consists of two segments of double-stranded RNA. J. Virol. 1979, 31, 584–589.
  9. Mundt, E.; Müller, H. Complete Nucleotide Sequences of 5′- and 3′-Noncoding Regions of Both Genome Segments of Different Strains of Infectious Bursal Disease Virus. Virology 1995, 209, 10–18.
  10. Wang, W.; He, X.; Zhang, Y.; Qiao, Y.; Shi, J.; Chen, R.; Chen, J.; Xiang, Y.; Wang, Z.; Chen, G.; et al. Analysis of the global origin, evolution and transmission dynamics of the emerging novel variant IBDV (A2dB1b): The accumulation of critical aa-residue mutations and commercial trade contributes to the emergence and transmission of novel variants. Transbounding Emerg. Dis 2022, 69, e2832–e2851.
  11. Xu, M.; Lin, S.; Zhao, Y.; Jin, J.; Tang, N.; Zhang, G. Characteristics of very virulent infectious bursal disease viruses isolated from Chinese broiler chickens (2012–2013). Acta Trop. 2015, 141, 128–134.
  12. Chen, F.; Liu, J.; Yan, Z.; Liu, D.; Ji, J.; Qin, J.; Li, H.; Ma, J.; Bi, Y.; Xie, Q. Complete genome sequence analysis of a natural reassortant infectious bursal disease virus in China. J. Virol. 2012, 86, 11942.
  13. Raja, P.; Senthilkumar, T.; Parthiban, M.; Thangavelu, A.; Gowri, A.M.; Palanisammi, A.; Kumanan, K. Complete genome sequence analysis of a naturally reassorted infectious bursal disease virus from India. Genome Announc. 2016, 4, e00709-16.
  14. Banda, A.; Villegas, P. Genetic characterization of very virulent infectious bursal disease viruses from Latin America. Avian Dis. 2004, 48, 540–549.
  15. Hernández, M.; Tomás, G.; Marandino, A.; Iraola, G.; Maya, L.; Mattion, N.; Hernández, D.; Villegas, P.; Banda, A.; Panzera, Y. Genetic characterization of South American infectious bursal disease virus reveals the existence of a distinct worldwide-spread genetic lineage. Avian Pathol. 2015, 44, 212–221.
  16. Jackwood, D.H.; Saif, Y.M. Antigenic diversity of infectious bursal disease viruses. Avian Dis. 1987, 31, 766–770.
  17. Rosenberger, J.; Cloud, S. Isolation and characterization of variant infectious bursal disease viruses. J. Am. Vet. Med. Assoc. 1986, 189, 357.
  18. Jackwood, D.J.; Schat, K.A.; Michel, L.O.; de Wit, S. A proposed nomenclature for infectious bursal disease virus isolates. Avian Pathol. 2018, 47, 576–584.
  19. Snyder, D.; Vakharia, V.; Savage, P. Naturally occurring-neutralizing monoclonal antibody escape variants define the epidemiology of infectious bursal disease viruses in the United States. Arch. Virol. 1992, 127, 89–101.
  20. Vakharia, V.N.; He, J.; Ahamed, B.; Snyder, D.B. Molecular basis of antigenic variation in infectious bursal disease virus. Virus Res. 1994, 31, 265–273.
  21. Eterradossi, N.; Toquin, D.; Rivallan, G.; Guittet, M. Modified activity of a VP2-located neutralizing epitope on various vaccine, pathogenic and hypervirulent strains of infectious bursal disease virus. Arch. Virol. 1997, 142, 255–270.
  22. Jackwood, D.J.; Sommer-Wagner, S.E. Amino acids contributing to antigenic drift in the infectious bursal disease Birnavirus (IBDV). Virology 2011, 409, 33–37.
  23. Bayliss, C.D.; Spies, U.; Shaw, K.; Peters, R.W.; Papageorgiou, A.; Muller, H.; Boursnell, M.E.G. A comparison of the sequences of segment A of four infectious bursal disease virus strains and identification of a variable region in VP2. J. Gen. Virol. 1990, 71, 1303–1312.
  24. Letzel, T.; Coulibaly, F.; Rey, F.A.; Delmas, B.; Jagt, E.; van Loon, A.A.M.W.; Mundt, E. Molecular and Structural Bases for the Antigenicity of VP2 of Infectious Bursal Disease Virus. J. Virol. 2007, 81, 12827–12835.
  25. Van der Marel, P.; Snyder, D.; Lütticken, D. Antigenic characterization of IBDV field isolates by their reactivity with a panel of monoclonal antibodies. DTW. Dtsch. Tierarztl. Wochenschr. 1990, 97, 81–83.
  26. Jackwood, D.J. Molecular epidemiologic evidence of homologous recombination in infectious bursal disease viruses. Avian Dis. 2012, 56, 574–577.
  27. Jackwood, D.; Cookson, K.; Sommer-Wagner, S.; Galludec, H.L.; De Wit, J. Molecular characteristics of infectious bursal disease viruses from asymptomatic broiler flocks in Europe. Avian Dis. 2006, 50, 532–536.
  28. Chettle, N.; Stuart, J.; Wyeth, P. Outbreak of virulent infectious bursal disease in East Anglia. Vet. Rec. 1989, 125, 271.
  29. Van den Berg, T.; Gonze, M.; Meulemans, G. Acute infectious bursal disease in poultry: Isolation and characterisation of a highly virulent strain. Avian Pathol. 1991, 20, 133–143.
  30. Berg, T.P.V.D. Acute infectious bursal disease in poultry: A review. Avian Pathol. 2000, 29, 175–194.
  31. Zhang, W.; Wang, X.; Gao, Y.; Qi, X. The Over-40-Years-Epidemic of Infectious Bursal Disease Virus in China. Viruses 2022, 14, 2253.
  32. Di Fabio, J.; Rossini, L.; Eterradossi, N.; Toquin, M.; Gardin, Y. European-like pathogenic infectious bursal disease viruses in Brazil. Vet. Rec. 1999, 145, 203–204.
  33. Mawgod, S.A.; Arafa, A.S.; Hussein, H.A. Molecular genotyping of the infectious bursal disease virus (IBDV) isolated from broiler flocks in Egypt. Int. J. Vet. Sci. Med. 2014, 2, 46–52.
  34. Barathidasan, R.; Singh, S.; Kumar, M.A.; Desingu, P.; Palanivelu, M.; Singh, M.; Dhama, K. Recurrent outbreaks of infectious bursal disease (IBD) in a layer farm caused by very virulent IBD virus (vvIBDV) in India: Pathology and molecular analysis. South Asian J. Exp. Biol. 2013, 3, 200–206.
  35. Hernández, M.; Banda, A.; Hernández, D.; Panzera, F.; Pérez, R. Detection of very virulent strains of infectious bursal disease virus (vvIBDV) in commercial broilers from Uruguay. Avian Dis. 2006, 50, 624–631.
  36. Hon, C.-C.; Lam, T.-Y.; Drummond, A.; Rambaut, A.; Lee, Y.-F.; Yip, C.-W.; Zeng, F.; Lam, P.-Y.; Ng, P.T.W.; Leung, F.C.C. Phylogenetic Analysis Reveals a Correlation between the Expansion of Very Virulent Infectious Bursal Disease Virus and Reassortment of Its Genome Segment B. J. Virol. 2006, 80, 8503–8509.
  37. Brown, M.D.; Skinner, M.A. Coding sequences of both genome segments of a European ‘very virulent’infectious bursal disease virus. Virus Res. 1996, 40, 1–15.
  38. Eterradossi, N.; Arnauld, C.; Tekaia, F.; Toquin, D.; Le Coq, H.; Rivallan, G.; Guittet, M.; Domenech, J.; Van den Berg, T.; Skinner, M. Antigenic and genetic relationships between European very virulent infectious bursal disease viruses and an early West African isolate. Avian Pathol. 1999, 28, 36–46.
  39. Mundt, E. Tissue culture infectivity of different strains of infectious bursal disease virus is determined by distinct amino acids in VP2. J. Gen. Virol. 1999, 80, 2067–2076.
  40. Qi, X.; Gao, H.; Gao, Y.; Qin, L.; Wang, Y.; Gao, L.; Wang, X. Naturally occurring mutations at residues 253 and 284 in VP2 contribute to the cell tropism and virulence of very virulent infectious bursal disease virus. Antivir. Res. 2009, 84, 225–233.
  41. Qi, X.; Lu, Z.; Wang, N.; Chen, Y.; Zhang, L.; Gao, L.; Li, K.; Ren, X.; Wang, Y.; Gao, H.; et al. Analysis of the function of D279N mutation of VP2 of infectious bursal disease virus. J. Integr. Agric. 2015, 14, 2618–2625.
  42. Islam, M.R.; Zierenberg, K.; Müller, H. The genome segment B encoding the RNA-dependent RNA polymerase protein VP1 of very virulent infectious bursal disease virus (IBDV) is phylogenetically distinct from that of all other IBDV strains. Arch. Virol. 2001, 146, 2481–2492.
  43. Escaffre, O.; Nouën, C.L.; Amelot, M.; Ambroggio, X.; Ogden, K.M.; Guionie, O.; Toquin, D.; Müller, H.; Islam, M.R.; Eterradossi, N. Both Genome Segments Contribute to the Pathogenicity of Very Virulent Infectious Bursal Disease Virus. J. Virol. 2013, 87, 14.
  44. Boot, H.J.; ter Huurne, A.A.H.M.; Hoekman, A.J.W.; Peeters, B.P.H.; Gielkens, A.L.J. Rescue of Very Virulent and Mosaic Infectious Bursal Disease Virus from Cloned cDNA: VP2 Is Not the Sole Determinant of the Very Virulent Phenotype. J. Virol. 2000, 74, 6701–6711.
  45. Boot, H.J.; Hoekman, A.J.W.; Gielkens, A.L.J. The enhanced virulence of very virulent infectious bursal disease virus is partly determined by its B-segment. Arch. Virol. 2005, 150, 137–144.
  46. Jackwood, D.J.; Sommer-Wagner, S.E.; Crossley, B.M.; Stoute, S.T.; Woolcock, P.R.; Charlton, B.R. Identification and pathogenicity of a natural reassortant between a very virulent serotype 1 infectious bursal disease virus (IBDV) and a serotype 2 IBDV. Virology 2011, 420, 98–105.
  47. Nouën, C.L.; Rivallan, G.; Toquin, D.; Darlu, P.; Morin, Y.; Beven, V.; de Boisseson, C.; Cazaban, C.; Comte, S.; Gardin, Y.; et al. Very virulent infectious bursal disease virus: Reduced pathogenicity in a rare natural segment-B-reassorted isolate. J. Gen. Virol. 2006, 87, 209–216.
  48. Qi, X.; Zhang, L.; Chen, Y.; Gao, L.; Wu, G.; Qin, L.; Wang, Y.; Ren, X.; Gao, Y.; Gao, H.; et al. Mutations of Residues 249 and 256 in VP2 Are Involved in the Replication and Virulence of Infectious Bursal Disease Virus. PLoS ONE 2013, 8, e70982.
  49. Delgui, L.; Oña, A.; Gutiérrez, S.; Luque, D.; Navarro, A.; Castón, J.R.; Rodríguez, J.F. The capsid protein of infectious bursal disease virus contains a functional α4β1 integrin ligand motif. Virology 2009, 386, 360–372.
  50. Yu, F.; Ren, X.; Wang, Y.; Qi, X.; Song, J.; Gao, Y.; Qin, L.; Gao, H.; Wang, X. A single amino acid V4I substitution in VP1 attenuates virulence of very virulent infectious bursal disease virus (vvIBDV) in SPF chickens and increases replication in CEF cells. Virology 2013, 440, 204–209.
  51. Fan, L.; Wu, T.; Hussain, A.; Gao, Y.; Zeng, X.; Wang, Y.; Gao, L.; Li, K.; Wang, Y.; Liu, C.; et al. Novel variant strains of infectious bursal disease virus isolated in China. Vet. Microbiol. 2019, 230, 212–220.
  52. Thai, T.N.; Jang, I.; Kim, H.-A.; Kim, H.-S.; Kwon, Y.-K.; Kim, H.-R. Characterization of antigenic variant infectious bursal disease virus strains identified in South Korea. Avian Pathol. 2021, 50, 174–181.
  53. Wang, Y.; Jiang, N.; Fan, L.; Niu, X.; Zhang, W.; Huang, M.; Gao, L.; Li, K.; Gao, Y.; Liu, C. Identification and pathogenicity evaluation of a novel reassortant Infectious Bursal Disease Virus (genotype A2dB3). Viruses 2021, 13, 1682.
  54. Wang, W.; Huang, Y.; Zhang, Y.; Qiao, Y.; Deng, Q.; Chen, R.; Chen, J.; Huang, T.; Wei, T.; Mo, M. The emerging naturally reassortant strain of IBDV (genotype A2dB3) having segment A from Chinese novel variant strain and segment B from HLJ 0504-like very virulent strain showed enhanced pathogenicity to three-yellow chickens. Transbound. Emerg. Dis. 2022, 69, e566–e579.
  55. Jiang, N.; Wang, Y.; Zhang, W.; Niu, X.; Huang, M.; Gao, Y.; Liu, A.; Gao, L.; Li, K.; Pan, Q. Genotyping and molecular characterization of infectious bursal disease virus identified in important poultry-raising areas of China during 2019 and 2020. Front. Vet. Sci. 2021, 8, 759861.
  56. Myint, O.; Suwanruengsri, M.; Araki, K.; Izzati, U.Z.; Pornthummawat, A.; Nueangphuet, P.; Fuke, N.; Hirai, T.; Jackwood, D.J.; Yamaguchi, R. Bursa atrophy at 28 days old caused by variant infectious bursal disease virus has a negative economic impact on broiler farms in Japan. Avian Pathol. 2021, 50, 6–17.
  57. Thai, T.N.; Yoo, D.-S.; Jang, I.; Kwon, Y.-K.; Kim, H.-R. Dynamics of the Emerging Genogroup of Infectious Bursal Disease Virus Infection in Broiler Farms in South Korea: A Nationwide Study. Viruses 2022, 14, 1604.
  58. Aliyu, H.B.; Hair-Bejo, M.; Omar, A.R.; Ideris, A. Genetic diversity of recent infectious bursal disease viruses isolated from vaccinated poultry flocks in Malaysia. Front. Vet. Sci. 2021, 8, 643976.
  59. Xu, A.; Pei, Y.; Zhang, K.; Xue, J.; Ruan, S.; Zhang, G. Phylogenetic analyses and pathogenicity of a variant infectious bursal disease virus strain isolated in China. Virus Res. 2020, 276, 197833.
  60. Fan, L.; Wu, T.; Wang, Y.; Hussain, A.; Jiang, N.; Gao, L.; Li, K.; Gao, Y.; Liu, C.; Cui, H.; et al. Novel variants of infectious bursal disease virus can severely damage the bursa of fabricius of immunized chickens. Vet. Microbiol. 2020, 240, 108507.
  61. Li, G.; Kuang, H.; Guo, H.; Cai, L.; Chu, D.; Wang, X.; Hu, J.; Rong, J. Development of a recombinant VP2 vaccine for the prevention of novel variant strains of infectious bursal disease virus. Avian Pathol. 2020, 49, 557–571.
  62. Fan, L.; Wang, Y.; Jiang, N.; Gao, L.; Li, K.; Gao, Y.; Cui, H.; Pan, Q.; Liu, C.; Zhang, Y.; et al. A reassortment vaccine candidate of the novel variant infectious bursal disease virus. Vet. Microbiol. 2020, 251, 108905.
  63. Lian, J.; Wang, Z.; Xu, Z.; Pang, Y.; Leng, M.; Tang, S.; Zhang, X.; Qin, J.; Chen, F.; Lin, W. Pathogenicity and molecular characterization of infectious bursal disease virus in China. Poult. Sci. 2022, 101, 101502.
  64. Müller, H.; Mundt, E.; Eterradossi, N.; Islam, M.R. Current status of vaccines against infectious bursal disease. Avian Pathol. 2012, 41, 133–139.
  65. Sun, J.; Lu, P.; Yan, Y.; Hua, X.; Jiang, J.; Zhao, Y. Sequence and analysis of genomic segment A and B of very virulent infectious bursal disease virus isolated from China. J. Vet. Med. Ser. B 2003, 50, 148–154.
  66. Pikuła, A.; Lisowska, A.; Jasik, A.; Śmietanka, K. Identification and assessment of virulence of a natural reassortant of infectious bursal disease virus. Vet. Res. 2018, 49, 89.
  67. Wei, Y.; Li, J.; Zheng, J.; Xu, H.; Li, L.; Yu, L. Genetic reassortment of infectious bursal disease virus in nature. Biochem. Biophys. Res. Commun. 2006, 350, 277–287.
  68. Cui, P.; Ma, S.-J.; Zhang, Y.-G.; Li, X.-S.; Gao, X.-Y.; Cui, B.-A.; Chen, H.-Y. Genomic sequence analysis of a new reassortant infectious bursal disease virus from commercial broiler flocks in Central China. Arch. Virol. 2013, 158, 1973–1978.
  69. Hon, C.-C.; Lam, T.T.-Y.; Yip, C.-W.; Wong, R.T.-Y.; Shi, M.; Jiang, J.; Zeng, F.; Leung, F.C.-C. Phylogenetic evidence for homologous recombination within the family Birnaviridae. J. Gen. Virol. 2008, 89, 3156–3164.
  70. He, C.-Q.; Ma, L.-Y.; Wang, D.; Li, G.-R.; Ding, N.-Z. Homologous recombination is apparent in infectious bursal disease virus. Virology 2009, 384, 51–58.
  71. Feng, X.; Zhu, N.; Cui, Y.; Hou, L.; Zhou, J.; Qiu, Y.; Yang, X.; Liu, C.; Wang, D.; Guo, J.; et al. Characterization and pathogenicity of a naturally reassortant and recombinant infectious bursal disease virus in China. Transbounding Emerg. Dis. 2022, 69, e746–e758.
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