Sequence analysis of the S1 glycoprotein of infectious bronchitis viruses: identification of a novel genotypic group in Australia

Abstract

Sequencing of the S1 genes of nine Australian strains of infectious bronchitis virus (IBV) identified two genotypically distinct groups of strains. The strains Vic S, V5/90, N1/62, N3/62, N9/74 and N2/75 comprised group I, sharing 80.7-98-3 % identity in their deduced amino acid sequences. All group I strains were able to replicate in the trachea and kidney but only four strains, Vic S, N1/62, N9/74 and N2/75, were nephropathogenic, the latter three causing mortalities ranging from 32 to 96%. Group II contained strains N1/88, Q3/88 and V18/91 which only replicated in the trachea, inducing no mortalities. These viruses showed 72.3-92.8 % amino acid identity to each other and only 53.8-61.7 % identity to viruses of the first group. They were also distinct from the Massachusetts 41 and D1466 strains (47-5-55.7% amino acid identity). Thus N1/88, Q3/88 and V18/91 form a new group of viruses which are genotypically distinct from all previously characterized IBV strains. No definite correlations were established between the S1 amino acid sequences and the nephropathogenicity of strains.

Typing infectious bronchitis virus strains using reverse transcription-polymerase chain reaction and restriction fragment length polymorphism analysis to compare the 3′ 7.5 kb of their genomes

“…Strains Vic S, S and I belong to the same serotype (B) by virus neutralization, and also to the same type by monoclonal antibody typing, while strain Armidale belongs to a different serotype (C) (Ignjatovic & McWaters, 1991). Six Australian reference strains, N3/62, V2/71, Q1/73, N2/75, N1/88 (Ignjatovic & McWaters, 1991) and V5/90 (Sapats et al , 1996) (Wadey & Faragher, 1981;Ignjatovic & McWaters, 1991;Ignjatovic et al, 2002).…”

“…Traditionally, IBV serotypes have been identified using virus neutralization or haemagglutination inhibition tests. Monoclonal antibodies, oligonucleotide fingerprinting and sequencing have also been used to type IBV isolates (Ignjatovic & McWaters, 1991;Cavanagh et al, 1992b;Kwon et al, 1993;Sapats et al, 1996). However, all these methods are labour intensive, expensive, time consuming, and require isolation and culture of viruses (Kwon et al, 1993).…”

Complete Nucleotide Sequences of S1 and N Genes of Infectious Bronchitis Virus Isolated in Japan and Taiwan

“…Homology search showed that the S1 protein sequences of strains JP8127, JP8443 and JP9758 were most closely related to that of an Australia field strain designated as N1-62 [8], whereas the S1 protein sequence of TW97-4 was most similar to that of a Taiwanese field strain designated as A1211 [11]. A phylogenetic tree was constructed by using the S1 protein sequences (Fig.…”

“…1). In this tree, strains JP8127, JP8443 and JP9758 fell into the branch containing viruses isolated from Australia [8], New Zealand and California [7] (Fig. 1).…”

Evaluation of a novel strain of infectious bronchitis virus emerged as a result of spike gene recombination between two highly diverged parent strains

“…SimPlot analysis examines relationships between nucleotide sequences at a set incremental level to provide a more accurate representation of the relationship between strains than using identity scores to compare entire stretches of genomic sequence. A point of crossover between the similarity plots indicates a shift from a high identity to a low identity (or vice versa), and therefore indicates a potential point of recombination (Lole et al, 1999 (Wadey & Faragher, 1981;Sapats et al, 1996;Ignjatovic et al, 2006;Mardani et al, 2006aMardani et al, , 2008Mardani et al, , 2010. The vaccine strains included in these analyses were Armidale, VicS and S (Wadey & Faragher, 1981).…”