A defective RNA (D-RNA), CD-61, derived from the Beaudette strain of the avian coronavirus infectious bronchitis virus (IBV), was rescued (replicated and packaged) using four heterologous strains of IBV as helper virus. Sequence analysis of the genomic RNA from the four heterologous IBV strains (M41, H120, HV10 and D207) identified nucleotide differences of up to 17% within the leader sequence ...

Preparation and Evaluation of Master seed prepared from Local variant infectious bronchitis virus (IBV) isolated from different poultry farms in Egypt and identified as IS/1494/06 nephropathogenic strain are very important point for vaccine production for controlling of infectious brobchitis(IB) disease in Egypt. Master seed of the virus (MSV) contained 10 EID50 per dose per bird free from bact...

Infectious bronchitis (IB) and Newcastle disease (ND) are highly contagious and the most economically important diseases of the poultry affecting respiratory tract and causing economic losses in poultry industry throughout the world. In the present study, the simultaneous detection and differentiation of causative agents of these diseases were investigated using duplex-RT-PCR. RNA was extracted...

There are major differences in the bioproduction potential of different coastal areas. The aim of this work is to review and discuss simple, operational criteria related to the bioproduction potential of coastal areas and to present and motivate an Index of Biological Value (IBV) for coastal management. This index is based on two key variables, which can be determined easily from bathymetric ma...

Infectious bronchitis virus (IBV) causes respiratory disease in chickens all over the world. Infectious bronchitis virus has many serotypes that do not confer cross protection against each other. The current study was designed to know which IBV types were circulating in Jordanian broiler chickens. Tracheal swabs from 175 broiler flocks at the acute phase of respiratory disease were collected. T...

Avian infectious bronchitis virus (IBV) primarily replicates in epithelial cells of the upper respiratory tract of chickens, inducing both morphological and immune modulatory changes. However, the association between the local immune responses induced by IBV and the mechanisms of pathogenesis has not yet been completely elucidated. This study compared the expression profile of genes related to ...

The purpose of this experimental study was to evaluate and record the effects of T-2 toxicity alone and in association with IBV infection on haematobiochemical parameters. A total of 128 one-week-old chicks were divided into four groups of 32 birds each and were treated respectively with T-2 toxin alone, IBV alone, T-2 toxin and co-infected with IBV, and no treatment (control) for a period of 6...

Coronavirus defective RNAs (D-RNAs) have been used for site-directed mutagenesis of coronavirus genomes and for expression of heterologous genes. D-RNA CD-61 derived from the avian coronavirus infectious bronchitis virus (IBV) was used as an RNA vector for the expression of chicken gamma interferon (chIFN-gamma). D-RNAs expressing chIFN-gamma were shown to be capable of rescue, replication, and...

UNLABELLED Coronaviruses from both the Alphacoronavirus and Betacoronavirus genera interfere with the type I interferon (IFN) response in various ways, ensuring the limited activation of the IFN response in most cell types. Of the gammacoronaviruses that mainly infect birds, little is known about the activation of the host immune response. We show that the prototypical Gammacoronavirus, infecti...

The detection methods for infectious bronchitis virus (IBV) are reviewed. Advantages and disadvantages of available techniques of IBV detection by virus isolation, antigen or genome detection, and serology are discussed. Factors of influence on the level of success in detection of IBV after a disease outbreak are discussed, as are the possibilities and dangers of strain classification by protec...