Molecular Epidemiology of Turkey Coronaviruses in Poland

Abstract

The only knowledge of the molecular structure of European turkey coronaviruses (TCoVs) comes from France. These viruses have a quite distinct S gene from North American isolates. The aim of the study was to estimate the prevalence of TCoV strains in a Polish turkey farm during a twelve-year period, between 2008 and 2019, and to characterize their full-length S gene. Out of the 648 flocks tested, 65 (10.0%, 95% CI: 7.9–12.6) were positive for TCoV and 16 of them were molecularly characterized. Phylogenetic analysis showed that these strains belonged to two clusters, one formed by the early isolates identified at the beginning of the TCoV monitoring (from 2009 to 2010), and the other, which was formed by more recent strains from 2014 to 2019. Our analysis of the changes observed in the deduced amino acids of the S1 protein suggests the existence of three variable regions. Moreover, although the selection pressure analysis showed that the TCoV strains were evolving under negative selection, some sites of the S1 subunit were positively selected, and most of them were located within the proposed variable regions. Our sequence analysis also showed one TCoV strain had recombined with another one in the S1 gene. The presented investigation on the molecular feature of the S gene of TCoVs circulating in the turkey population in Poland contributes interesting data to the current state of knowledge.

Targeted detection and molecular epidemiology of turkey coronavirus spike gene variants in turkeys and chickens

“…Variants detected in other countries have been shown to have an S gene with significant sequence variation from U.S. strains. 3 Our data also confirm that sequences of the S gene from contemporary variants differ from those obtained in the mid-to-late 1990s and early 2000s, as would be expected, based on replication errors known to occur with RNA viruses and the continued evolution of the viral attachment protein.…”

“…7,8 Epidemiologic evaluation of S genes from European variants of TCoV compared to those from the United States shows that the European viruses are distinct from U.S. variants, suggesting separate evolutionary pathways on the 2 continents. 3 The S glycoprotein is necessary for viral attachment to host cells. The change in the S protein in IBV led to the host shift to turkeys.…”

“…7,8 Epidemiologic evaluation of S genes from European variants of TCoV compared to those from the United States shows that the European viruses are distinct from U.S. variants, suggesting separate evolutionary pathways on the 2 continents. 3…”

Avian infectious bronchitis virus (AIBV) review by continent

“…Beudette GI-1 (Gough et al, 2008;Franzo et al, 2014;Valastro et al, 2016;Lisowska et al, 2017;Moreno et al, 2017;…”

“…The whole-genome analysis of the Polish GI-23 lineage revealed that the mosaic pattern of the viral genome from other IBV strains descended from the QX-like (GI-19), 793Blike (GI-13), and mass-like (GI-1) serotypes. The exact origin of the virus that infects the Polish chicken population is still unknown (Lisowska et al, 2017).…”