Abstract of research

ISOLATION AND MOLECULAR CHARACTERIZATION OF INFECTIOUS BRONCHITIS VIRUS FROM BALADI CHICKENS

Maged Gomaa Hemida1,2

Abstract

Infectious bronchitis virus (IBV) is one of the most important threats of the poultry industry worldwide including Egypt. It is usually associated with high morbidity and mortality among the affected bird flocks. All ages and breeds of chickens are susceptible to IBV infection. Commercial chickens are highly susceptible to IBV moreover, Baladi chickens can also be infected with IBV and develop typical picture of the IBV in the affected chickens. Despite the massive vaccination, we faced with continuous outbreaks of infectious bronchitis virus within the poultry industry causing a huge economic loss to the poultry units. The main goal of the current study was to check the possibility of isolation of IBV from affected Baladi chickens and perform molecular characterization of the isolated viruses. Moreover, to compare the sequence of the isolated viruses to the already published Egyptian strains in the gene bank. Two hundred samples from Baladi chickens showing respiratory manifestations were obtained from small mini-farms and from cases submitted to several private veterinary clinics. The received birds were showing respiratory manifestations in the form of coughing, sneezing and rales. Tracheal swabs, trachea, bronchi and lungs had been collected. Virus isolation using 9- 11 days embryonated Baladi chickens obtained from non-vaccinated IBV birds. Concentration of the virus was done and viral RNA was extracted. Electron microscope showed typical coronavirus morphology. Amplification of a partial Spike-1 glycoprotein was dons. Sequencing analysis of the obtained sequence revealed high degree of similarity (83 %) to the previously isolated Egyptian strains. These results confirmed that, IBV can infect Baladi chickens and probably the circulated strains in the commercial broiler chickens can infect the Baladi chickens as well.