Elsevier

Poultry Science

Volume 89, Issue 3, 1 March 2010, Pages 439-446
Poultry Science

Immunology, Health, and Disease
Identification of intertypic recombinant infectious bronchitis viruses from slaughtered chickens1

https://doi.org/10.3382/ps.2009-00322Get rights and content
Under a Creative Commons license
open access

ABSTRACT

Avian coronavirus infectious bronchitis virus (IBV) poses a major threat to the global poultry industry. New IBV geno- and serotypes are continually reported. However, information on IBV prevalence is not frequently addressed in these reports. This study reports on a viral surveillance program in Taiwan from 2005 to 2006 with sampling conducted in poultry slaughterhouses. The genetic features of the obtained field isolates were investigated using sequence analysis and SimPlot analysis. A 1-directional neutralization test was performed to examine the antigenic variations among the collected viruses. The selection pressures that may contribute to the evolution of Taiwan IBV during recent decades were assessed. The surveillance program revealed that 8 out of 47 flocks (17%) were IBV-infected, from which 13 IBV isolates were recovered. Based on the phylogenetic analysis of the S1 gene, 11 of 13 isolates (84.6%) clustered with Taiwan group I. One IBV isolate showed evidence of frequent recombination events with China-like IBV in the spike glycoprotein (S) gene. Another isolate demonstrated the incorporation of China-like and H120-like genome fragments within the S2 gene and the membrane protein (M) gene region, respectively. Some antigenic changes were found in the 1-directional neutralization test. However, no positive selection pressures were related to those variations in the S1 genes among Taiwan IBV. Based on our work, we suggest that sampling chickens in poultry slaughterhouses is an effective and valuable means of compiling viral prevalence data, particularly in situations where there is subclinical infection. Infectious bronchitis viruses from slaughtered chickens revealed intertypic genetic recombination and antigenic diversity.

Key words

infectious bronchitis virus
poultry slaughterhouse
sequence analysis
serotype
viral surveillance

Cited by (0)

1

The nucleotide sequence data reported in this paper have been submitted to the GenBank (Mail Stop K710, Los Alamos National Laboratories, Los Alamos, NM) nucleotide sequence database and have been assigned the accession numbers GQ229232 and GQ229237 to GQ229258.