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

Evaluation of a novel strain of infectious bronchitis virus emerged as a result of Spike gene recombination between two highly diverged parent strains. Avian Pathol. 2014 Apr 14;:1-25 Authors: Hewson KA, Noormohammadi AH, Devlin JM, Browning GF, Schultz BK, Ignjatovic J Abstract The emergence of new variant strains of the poultry pathogen infectious bronchitis virus (IBV) is continually reported worldwide, owing to the labile nature of the large single-stranded RNA IBV genome. High resolution melt (HRM) curve analysis previously detected a variant strain, N1/08, and the present study confirmed that this strain had emerged as a result of recombination between Australian subgroup 2 and 3 strains in the Spike gene region, in a similar manner reported for Turkey coronaviruses. The S1 gene for N1/08 had highest nucleotide similarity with subgroup 2 strains, which is interesting considering subgroup 2 strains have not been detected since the early 1990s. Simplot analysis of the 7.2 kb 3' end of the N1/08 genome with the same region for other Australian reference strains identified the sites of recombination as immediately upstream and downstream of the S1 gene. A pathogenicity study in 2-week-old chickens found that N1/08 had similar pathogenicity for chicken respiratory tissues to that reported for subgroup 2 strains than subgroup 3 strains. The results of this study demonstrate that recombination is a mechanism utilised for the emergence...
Source: Avian Pathology - Category: Pathology Authors: Tags: Avian Pathol Source Type: research