Phylogeny and evolution of infectious bursal disease virus circulating in Turkish broiler flocks

Abstract

The emergence of new infectious bursal disease virus ( IBDV ) variants can threaten poultry health and production all over the world causing significant economic losses. Therefore, this study was performed to determine IBDV molecular epidemilogy, VP2 gene variation, and corresponding pathological lesions in IBDV infected chickens in Turkey. For this, 1855 bursa of Fabricius samples were collected from 371 vaccinated broiler flocks. Atrophia and haemorrhages were seen in the bursa Fabricius of very virulent IBDV ( vvIBDV ) infected chickens. Partial VP2 gene was sequenced and phylogenetic, recombination, and evolutionary analyses were performed. 1548 (83.5%) out of 1855 of bursa of Fabricius samples were IBDV positive and 1525 of those could be sequenced. The recombination analysis did not detect occurrence of any recombination event among the Turkish strains. Among 1525 sequenced samples, 1380 of them were found to be classical strains. Among 1380 classical strains, 1317 were similar to IBDV 2512, 11 to Faragher 52/70, 40 to 228 E, and 12 to Lukert strain. Out of 1525 reverse transcriptase ploymerase chain reaction positive samples, 144 of them were found to be similar to vvIBDV-VP2 gene reported to GenBank previously. The phylogenetic tree performed on a broad sequence dataset demonstrated grouping of vvIBDV Turkish strains in three different clusters, including sequences collected also from Iraq and Kuwait (Cluster 1), Indian (Cluster 2), and a distinct Turkish-only cluster (Cluster 3). The evolutionary rate estimation on branches/clades including Turkish strain mirrored the expected one for RNA viruses and no significant differences were found among different considered branches. In conclusion, results of this study indicate that vvIBDV strains similar to those circulating in various countries in the Middle East are present and undergoing evolution in chickens from Turkish broiler flocks. This point needs to be taken into account in planning adequate control strategies.

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

“…Regarding the dIBDV strains, three main successive inter-continental migration events were detected: to vvIBDV and 90.5% were vaccine-like cIBDV (Yilmaz et al, 2019). A similar scenario of co-circulation of vvIBDV and vaccine-like strains was reported in more limited studies performed in Iran, Iraq, Pakistan, Egypt, Jordan and Kuwait (Amin & Jackwood, 2014;Khan et al, 2019;Michel & Jackwood, 2017;Norouzian, Farjanikish, & Hosseini, 2017;Samy et al, 2019).…”

“…Except for the recent inter‐continental event of introduction from Brazil and Canada, there are no additional records of the dIBDV lineage in Western Asia. An extensive surveillance in Turkey found that 9.5% of the strains corresponded to vvIBDV and 90.5% were vaccine‐like cIBDV (Yilmaz et al, ). A similar scenario of co‐circulation of vvIBDV and vaccine‐like strains was reported in more limited studies performed in Iran, Iraq, Pakistan, Egypt, Jordan and Kuwait (Amin & Jackwood, ; Khan et al, ; Michel & Jackwood, ; Norouzian, Farjanikish, & Hosseini, ; Samy et al, ).…”

Genetic Analysis of Field Isolates of Infectious Bursal Disease Virus in Iraqi Farms

“…These results are due to antigenic drift in inside or outside of hydrophilic region and hydrophobic region of VP2 that leads to some sites to become more stable and others less stable. Also, the mutations of VP2 are responsible for viral antigenicity, pathogenicity, and tissue tropism as reported by (23,28). The VP2-3-4 of segment A of two Iraqi detected strains were closely related to the Chinese strain (under accession number AY628217.1) both with 99% homology and the VP5 of segment A of two Iraqi detected strains were showed a high nucleotide homology to the Chinses strain (under accession number AF692943.1) both with 99%.…”

First report on the molecular detection, phylogeny, virological and pathological investigations of Avibacterium paragallinarum in chickens in Turkey

“…Samples were also screened to detect the presence of infectious bronchitis virus (IBV) (25), infectious bursal disease virus (IBDV) (24), avian metapneumovirus (aMPV) (5), and infectious laryngotracheitis (ILTV) (26) as part of routine diagnostic work, as described previously. For all PCR reactions to detect either DNA or viral RNA, posi-tive and negative controls were used.…”

“…Many viral and bacterial diseases are of economic significance in the broiler industry worldwide (5,6,22,24). Although the importance of infectious coryza caused by A. paragallinarum and its economic consequences in broiler flocks have previously been discussed in a number of studies (10,18), the available information on many countries, including Turkey, is limited.…”