First characterization of a Middle-East GI-23 lineage (Var2-like) of infectious bronchitis virus in Europe

Abstract

Variants assigned to GI-23 lineage of infectious bronchitis virus (IBV), formerly called Var2, have circulated for nearly 20 years only in countries of the Middle East. Strains of this lineage were first identified in Israel in 1998. More severe form of the virus appeared in 2006, when the second wave of Var2 epidemic has spread over the Middle East region. The present study describes the detection and detailed genetic characterization of the GI-23 viruses in Poland. The full-length genome of gammaCoV/Ck/Poland/G052/2016 strain consists of 27596 nucleotides and has typical organization for IBV (UTR5'-POl-S-3a-3b-E-M-4b-4c-5a-5b-N-UTR3'). The phylogenetic analysis of the complete sequence showed that it formed separate branch distinct from all of the full-length genome sequences analyzed in this study. Recombination analyses with other gammacoronaviruses revealed that Polish GI-23 strain may originate from recombination events and potential donors of build-in sequences are IBV of GI-1, GI-13 and G-19 lineages (Mass-, 793B- and QX-like strains, respectively). The 1a, 1b and N genes were involved in these recombination events. The source of virus introduction to the chicken population in Poland is unknown.

Research Note: First evidence of infectious bronchitis virus Middle-East GI-23 lineage (Var2-like) in Germany

“…The symptoms observed in the case report are consistent with those described in former outbreaks in Egypt, Turkey, and Poland (Yilmaz et al, 2016;Zanaty et al, 2016;Lisowska et al, 2017). Birds showed respiratory as well as nephropathogenic symptoms.…”

“…The isolate described here clusters in the Middle-East G-23 lineage and shows close relationship to the commercially available vaccine TAbic IBVAR206 (Phibro, Teaneck, NJ) and to recently published Polish IBV GI-23 isolates (Lisowska et al, 2017) (Figure 1).…”

“…The genotype Israel strain 2, detected here, was first described in Israel (Meir et al, 2004). In 2015, this virus strain was detected in broilers and layers in Poland (Lisowska et al, 2017). This was the first isolation in Europe.…”

“…The 479 base pair (bp) fragment is coding for the S1 spike protein (bp 112-590, aa 38-196; GenBank: MN004969) and contains the HVR I and II. The sequence was compared with a prototype strain sequence of IBV GI-23 lineage (according to Valastro et al (Valastro et al, 2016)) to polish isolates (Lisowska et al, 2017) and to the TAbic IBVAR206 vaccine strain using the same nucleotide segment (bp 112-590) for analysis. A bovine coronavirus sequence serves as outgroup.…”

“…For the continuous improvement of those, the knowledge of circulating field viruses in the specific region is essential. Recently an IBV variant called Israel strain 2 belonging to the GI-23 lineage was detected in Europe (Valastro et al, 2016;Lisowska et al, 2017). The strain was first described in Israel, causing severe respiratory and nephropathogenic lesions (Meir et al, 2004).…”