A reverse transcriptase-polymerase chain reaction survey of infectious bronchitis virus genotypes in Western Europe from 2002 to 2006

Abstract

A survey of infectious bronchitis virus (IBV) genotypes in poultry flocks in selected countries in Western Europe was carried out between March 2002 and December 2006. Identification of IBV was by reverse transcriptase-polymerase chain reaction of RNA extracted from oropharyngeal swabs taken from poultry flocks exhibiting signs of clinical disease thought to be attributable to IBV. Part of the hypervariable S1 gene of IBV was sequenced to differentiate between the various genotypes. During the survey, 4103 samples were processed, of which 2419 (59%) were positive for IBV. The predominant IBV genotypes detected were 793B and Massachusetts. The third and fourth most common genotypes were two new economically important field types: Italy02, and a virus similar to genotypes originally detected in China called QX. Analysis of the partial S1 sequences of the genotypes detected suggested that approximately 50% of all 793B, Massachusetts types and D274 IBVs were identical to the homologous commercially available live vaccines. Since 2004 the prevalence of Italy02 (present in all countries from which samples were received) has been declining in all countries except Spain, where it appeared to be the predominant genotype. Since 2004 an IBV genotype has been detected in Holland, Germany, Belgium and France similar to QX and the incidence has increased. QX was not detected in the United Kingdom or Spain. When detections thought to be attributable to vaccines were removed, the dominant genotype in France and Europe overall was 793B; in Germany, Holland and Belgium, it was QX-like IBV; and in the United Kingdom and Spain the dominant genotype was Italy02. The present study is the first to identify the prevalence of both Italy02 and QX field-type variants in poultry flocks in Western Europe. Several novel genotypes have also been detected.

Phylogeny and S1 Gene Variation of Infectious Bronchitis Virus Detected in Broilers and Layers in Turkey

“…The AvCoV-IBV isolates detected in this study were found to be similar to IBV isolates detected in Israel, Turkey, Iraq, Jordan, and Egypt like strains KF179074, HM802259, EU780077, JX027070, JX173488, and KF153245, but different from IBV isolates QX and Italy-02 (EU780077) (1,15,23,29), detected in other European countries. The predominance of IBV genotypes representing isolates belonging to Asian-type lineages, found in this study, suggests that Turkey has more cross-border poultry trade with Middle Eastern countries than with European countries.…”

“…Amongst the IBV strains identified in the broiler flocks, 17.2% represented the detection of the IBV Ma5 and H120 vaccine strains (95.6%-99.2%) and 48.9% represented the Israel variant 2 isolate (94.8%-99.4%), whereas all of the layer flock-derived sequences were represented in the 4/91 vaccine strain (96.2%-99.5%). Results from field surveys for assessing the presence of IBV in chickens in Western Europe showed 59% positive for AvCoV-IBV with about 50% of the positive samples representing identification of vaccine strains (29). Similarly, vaccine strains were also detected following the assessment of poultry in the Middle East for the presence of IBV (13,19,25).…”

Genetic mutations in live infectious bronchitis vaccine viruses following single or dual in vitro infection of tracheal organ cultures

“…Extracted RNA was subjected to RT-PCR to detect a 393 bp partial-S1 sequence in the hypervariable region of the S1 gene (Awad et al, 2014;Cavanagh et al, 1999;Ganapathy et al, 2015;Worthington et al, 2008). In previous genotyping studies, this region was targeted due to the increased genetic variation possibilities.…”

Serological Studies of Infectious Bronchitis Vaccines against Japanese Field Isolates of Homologous and Heterologous Genotypes

“…In a previous study, we identified strains of the 793B genotype, which are the same as the 4/91 vaccine strain, as a new variant in Japan [20]. In Japan, field isolates of 793B had not been isolated until 2003, but IBVs of 793B have been widely isolated in several European countries since 1991 [4,8,23].…”