in the present study, 360 male day-old broiler chicks were used to determine the effect of mixed livevaccines of newcastle disease (nd) and infectious bronchitis (ib) on serum and local antibody responses toib. chicks were randomly divided into 12 treatment groups of 3 replicates and reared for 40 days on floorpens. groups 1 to 5 received mixed nd and ib vaccine. groups 7 to 11 received ib vacc...

an indirect enzyme–linked immunosorbent assay (elisa) was developed for screening of antibody to avian infectious bronchitis virus (ibv). antigen was prepared from whole-purified ibv massachusetts serotype (br 801 strain). optimum dilution with minimum background for antigen concentration, rabbit anti-chicken conjugate and sera in developed elisa was determined 0.1μg/ml, 1:3000 and 1:100, respe...

This experimental study was carried out to induce a co-infection of H9 AIV and IBV with inoculumsprepared from tracheal scrubbed epithelium tissues in natural co-infected birds to rule out the effect of fieldundesired environmental conditions and also other infectious causative agents. Eighty 1-day-old broilerswere randomly divided into four equal groups. At 21 days of age, three test groups we...

The synergistic role of infectious bronchitis virus (IBV) and mixed infections of Mycoplasma synoviae (MS) and Escherichia coli (EC) in the airsacculitis syndrome was evaluated in gnotobiotic chickens. Relative air sac lesion score indexes, in descending order of severity, from various combinations of organisms were: 9.5-IBV, MS, EC; 6.8-IBV, EC; 4.5-IBV, MS; 2.7-IBV; and 0.5-MS, EC. Infectious...

0

In the 3' non-coding region of the genomes of infectious bronchitis virus, an avian coronavirus and the picornavirus equine rhinovirus serotype 2, there is a motif with remarkable similarity, both in sequence and folding, to the second RNA stem-loop from the 3' end of the genomes of human astroviruses. This motif was also found in astroviruses of sheep, pig and turkey, suggesting that it is a c...

Infectious bronchitis is a highly contagious respiratory disease of poultry caused by the coronavirus infectious bronchitis virus (IBV). It was thought that coronavirus virions were composed of three major viral structural proteins until investigations of other coronaviruses showed that the virions also include viral non-structural and genus-specific accessory proteins as well as host-cell prot...

Infectious bronchitis virus (IBV) causes a costly respiratory viral disease of chickens. The role of wild birds in the epidemiology of IBV is poorly understood. We detected diverse coronaviruses by PCR in wildfowl and wading birds in England. Sequence analysis showed some viruses to be related to IBV.

Infectious bronchitis is a respiratory disease of chickens that is caused by the coronavirus infectious bronchitis virus (IBV). Virtually all broiler and layer breeder flocks are routinely vaccinated against IBV. Two hatches of 1-day-old chicks from four lines were mistakenly vaccinated for infectious bronchitis using a moderately attenuated vaccine designed for chicks of an older age. The vacc...