Serotype Identification of Avian Infectious Bronchitis Virus by RT-PCR of the Peplomer (S-1) Gene

Abstract

The S-1 peplomer gene sequences of 31 strains of avian coronavirus infectious bronchitis virus (IBV) from North America, Europe, and Australia were compared to identify common and unique regions for possible diagnostic applications. S-1 sequences that were conserved among serotypes and sequences that were variable between serotypes were identified. Based on conserved S-1 gene sequences, "general" degenerate oligonucleotide primers were designed that amplified IBV genomic RNA by the reverse transcriptase polymerase chain reaction (RT-PCR) procedure regardless of serotype. Primers specific for IBV serotypes Massachusetts, Connecticut, Arkansas, JMK, Delaware (DE/072/92), and California (CA/633/85) were designed from regions of the S-1 gene exhibiting extensive sequence hypervariability. The ability to identify these six serotypes of IBV by RT-PCR was demonstrated by testing the serotype-specific primers on a panel of unknown samples that included 30 reference strains and field isolates previously characterized by virus neutralization (VN). The use of serotype-specific primers in RT-PCR provides a rapid and accurate means of identifying IBV.

Infectious bronchitis virus S1 gene sequence comparison is a better predictor of challenge of immunity in chickens than serotyping by virus neutralization

“…NC 001451) starting after the conserved CK4 primer site and ending prior to the conserved CK2 primer site (Keeler et al ., 1998). Wang et al .…”

Detection of infectious bronchitis virus

“…Isolates of the same serotype or protectotype can differ substantially in some genes (Cavanagh et al, 1992a), while different serotypes or protectotypes can have remarkably high similarity between their genomes (Clewley et al, 1981, Kusters et al, 1987Williams et al, 1992;Cavanagh et al, 1992a,b;Capua et al, 1998;Minta et al, 1998). Several studies (Lin et al, 1991;Kwon et al, 1993b;Keeler et al, 1998) have reported a high correlation between the genotype and serotype of strains, while other papers present conflicting data between the genotype and serotype and/or protectotype (Clewley et al, 1981;Kusters et al, 1987;Capua et al, 1998;Hein et al, 1998;Minta et al, 1998). Also, genotyping a strain by two different genotyping methods may result in contradictory results (Capua et al, 1998(Capua et al, , 1999.…”

“…Especially when there is suspicion in the field that the genotype of recent isolates does not provide accurate information about the true antigenic nature of these IBV isolates, conventional testing (serotyping) and especially in vivo studies are required (Jia et al, 1995;Hein et al, 1998;Keeler et al, 1998).…”

“…Sequencing can be performed on any part of the genome, but is usually performed on a selected part of the S protein gene (Binns et al, 1985(Binns et al, , 1986Niesters et al, 1986;Cavanagh et al, , 1992aCavanagh et al, ,b, 1997Kusters et al, 1990;Wang et al, 1994;Wang & Tsai, 1996;Keeler et al, 1998), the M gene (Boursnell et al, 1984;Cavanagh et al, 1992a), or the N gene (Zwaagstra et al, 1992;Williams et al, 1992). Based on sequence data, a phylogenic tree can be made, revealing the genomic relatedness between different strains.…”

“…Also, the occurrence of recombinations between different IBV strains during mixed infections Kusters et al, 1989Kusters et al, , 1990Cavanagh et al, 1992a;Williams et al, 1992;Zwaagstra et al, 1992;Jia et al, 1995;Kottier et al, 1995) hampers the translation of data on a genotype to a serotype or protectotype. Keeler et al (1998) reported the results of a RT-PCR using two general primers and six oligonucleotide primers which were designed to specifically amplify and identify six North American serotypes. The reported correlation between the results of the RT-PCR and serotyping by VNT was very high.…”