Molecular epidemiology of infectious bronchitis virus in Poland from 1980 to 2017

Abstract

A B S T R A C TThe presence of infectious bronchitis virus (IBV) was identified for the first time in the poultry population in Poland at the end of the 1960s. From this time a few waves of epidemics caused by different IBV variants spread across the country. In order to gain more insight into the molecular epidemiology of IBV in Poland, in the present study the S1 coding region of 34 IBV isolates and nearly whole genome of 10 strains collected over a period of 38 years was characterized. Phylogenetic analysis showed that these strains belonged to five recently established IBV lineages: GI-1, GI-12, GI-13, GI-19 and GI-23. Additionally, two strains from 1989 and 1997 formed a separate branch of the phylogenetic tree categorized as unique early Polish variants, and one strain was revealed to be the recombinant of these and GI-1 lineage viruses. Irrespective of year of isolation and S1-dependent genotype, the genome sequences of Polish IBV strains showed the presence of six genes and 13 ORFs: 5′UTR-1a-1b-S-3a-3b-E-M-4b-4c-5a-5b-N-6b-3′UTR, however their individual genes and putative proteins had different lengths. The phylogenetic analyses performed on the genome of ten Polish IBV strains revealed that they cluster into different groups. The Polish GI-1, GI-19 and GI-23 strains cluster with other similar viruses of these lineages, with the exception of the two strains from 1989 and 1997 which are different. It seems that in Poland in the 1980s and 1990s IBV strains with a unique genome backbone circulated in the field, which were then replaced by other strains belonging to other IBV lineages with a genome backbone specific to these lineages. The recombination analysis showed that some Polish strains resulted from a recombination event involving different IBV lineages, most frequently GI-13 and GI-19.

Virulence Properties of GI-23 Infectious Bronchitis Virus Isolated in Poland and Efficacy of Different Vaccination strategies

“…The virus shows variable tissue tropism and virulence properties, and the immunoprophylaxis is the primary measure to control IBV infections [ 13 ]. The molecular surveillance of IBV exhibited that GI-23 strains are frequently recognised in recent years in Poland [ 11 ]. Field observation showed that the disease outcome was mainly associated with medium respiratory signs and watery diarrhea.…”

“…Furthermore, the emergence of closely-related Var2 strains was reported in Romania and Germany, indicating the spread of this variant in Europe [ 9 , 10 ]. In Poland, in the following years, the number of Var2 cases had increased accounting for over 28% of all lineages detected between 2018–2019 [ 8 , 11 ]. Six months after the first IBV GI-23 disease outbreak, the registration of the homologous vaccine for this IBV lineage (Tabic IB Var206) was approved by the Polish veterinary authorities, which made a total of five virus types (GI-1 = Mass, GI-(1 + 12) = Mass + D274, GI-13 = 793B, and GI-19 = QX) contained in many live attenuated vaccines available in Poland, which are used in combination or alone.…”

The taxonomy, host range and pathogenicity of coronaviruses and other viruses in the Nidovirales order

“…Igacovirus subgenus contains 3 species : avian coronavirus , avian coronavirus 9203 , and duck coronavirus 2714 . Viruses of Igacovirus subgenus primarily infect birds, such as chickens ( Gallus gallus ), turkeys, ducks, geese, pheasants, partridges, pigeons and peafowl (Cavanagh et al 2002 ; Jonassen et al 2005 ; Cavanagh 2007 ; Sun et al 2007 ; Domanska-Blicharz et al 2020 ). Infectious bronchitis virus (IBV) is the prototype virus of Igacovirus subgenus, and various serotypes of IBV have been identified.…”

Recombinant turkey coronavirus: are some S gene structures of gammacoronaviruses especially prone to exchange?

“…This part of the genome also encodes a few low-molecular-weight accessory proteins whose number and nature vary depending on the species and even the ACoV strain. These proteins would be 3a, 3b, 4b, 4c, 5a, and 5b, although TCoV, GfCoV, and some IBV strains also have an ORF NS6 located downstream of the nucleocapsid protein encoding the 6b protein ( Maurel et al., 2011 ; Ducatez et al., 2015 ; Brown et al., 2016 ; Domanska-Blicharz et al., 2020 ). In addition to their similar genome structure, these strains also have a close genetic relationship as nucleotide similarity of whole genomes between TCoV/GfCoV and IBV strains is higher than 86%.…”

“…The presence of IBV was identified for the first time in the chicken population in Poland at the end of the 1960s, and then, a few waves of epidemics caused by different IBV variants appeared every 8–11 yr: GI-1 in 1988, GI-13 in 1997, GI-19 in 2004, and GI-23 in 2015. During this period, IBV strains described as unique early Polish variants and recombinants were also detected ( Domanska-Blicharz et al., 2020 ). In turn, the prevalence of TCoV in the Polish turkey population was estimated at the level of about 6.5%.…”