Origin and global spreading of an ancestral lineage of the infectious bursal disease virus

Abstract

Infectious bursal disease virus (IBDV) is an economically relevant and widespreadpathogen that produces immunosuppression in young chickens. IBDV is genetically classified into seven genogroups (G1-G7), where the traditional classic, variant and very virulent strains correspond to G1, G2 and G3, respectively. The G4 strains, also known as 'distinct' (dIBDV), have recently acquired increased relevance because of their prevalence and notorious impair to the poultry industry in South America. Here, worldwide dIBDV strains were studied using phylogenetic and phylodynamic approaches. The phylogenetic analyses performed using partial and complete sequences of both viral segments (A and B) consistently clustered the dIBDV strains in a monophyletic group. The analyses of the VP5, polyprotein and VP1 coding regions identified amino acid residues that act as markers for the identification of the entire dIBDV group or different sub-populations. The phylodynamic analyses performed using the hypervariable region of VP2 indicated that the dIBDV strains emerged in the early 1930s in Eastern Europe, shortly after the emergence of classic strains (1927) and before variant (1949) and very virulent strains (1967). The analysis of the migration routes indicated that after its emergence, the dIBDV strains spread to Eastern Asia around 1959, to Brazil around 1963, and to Argentina around 1990. These inter-continental migrations resulted in three sub-populations that are currently represented by strains from (a) Brazil, (b) Eastern Asia and Canada, and (c) Eastern Europe, Argentina and Uruguay. Taken together, our results highlight the complex evolutionary history of IBDV and the importance of new phylodynamic data to unravel and nearly follow the different evolutionary pathways taken by this important poultry pathogen.

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

“…Over the past few decades, tMRCA of different IBDV genogroups has been gradually identified, although there are still some debates. The emergence of cIBDV was identified in the late 1920s (Silva et al., 2013; Tomás et al., 2020), which is consistent with the fact that IBD was first described in the United States in 1962 (Cosgrove, 1962). The vvIBDV lineage was identified in the late 1960s and the early 1970s (Alfonso‐Morales et al., 2013; Hon et al., 2006; Tomás et al., 2020), followed by the first acute severe outbreak of vvIBDV in Europe in 1987 (Chettle et al., 1989).…”

“…The vvIBDV lineage was identified in the late 1960s and the early 1970s (Alfonso- Morales et al, 2013;Hon et al, 2006;Tomás et al, 2020), followed by the first acute severe outbreak of vvIBDV in Europe in 1987 (Chettle et al, 1989). There are two views on the origin of the dIBDV lineage.…”

“…There are two views on the origin of the dIBDV lineage. One is that it originated in the 1930s (95% HPD, 1898–1963), which is similar to cIBDV (Tomás et al., 2020), and the other is that it originated in 1968 (95% HPD, 1960–1974) (de Fraga et al., 2019). Similarly, for the origin time of avIBDV, it was estimated at 1980s (Alfonso‐Morales et al., 2013) and 1949 (95% HPD, 1925–1971) (Tomás et al., 2020), respectively.…”

Genetic Diversity of Recent Infectious Bursal Disease Viruses Isolated From Vaccinated Poultry Flocks in Malaysia

“…Similarly, the rare amino acid substitution, C595S, that was found in the variant strain and three other vvIBDV, is located at the thumb of the central polymerase. The residue is mostly detected in distinct IBDV from Uruguay and Argentina (65). Of the four isolates with the characteristic TDN tripeptides at positions 145/146/147, respectively, UPM1056/2018, IBS624/2017, and IBS536/2017 strains presented mutation at position A664T.…”

Assessing the antigenicity of different VP3 regions of infectious bursal disease virus in chickens from South Brazil

“…The customization of diagnostic methodologies requires the genetic characterization of the circulating strains, whose variability is little known. Few works report the genetic variability of IBDV in Brazil [ 25 – 34 ].…”