R Majdani - Department of Microbiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
K Mardani. - Department of Food Hygiene and Quality Control, Faculty of VeterinaryMedicine, Urmia University, Urmia, Iran
A Morshedi - Department of Microbiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
M Vasfi Marandi - Department of Clinical Sciences, Faculty of VeterinaryMedicine Department of Clinical Sciences, Faculty of VeterinaryMedicine

Infectious bronchitis (IB) is an economically important disease of chickens. Due to the emergence of new variants of infectious bronchitisvirus (IBV), the control of IB has become a serious problem for the poultry industry worldwide. In the present study, the nucleocapsid gene (N) and 3'untranslated region (UTR) of two IBVs isolated from Iranian poultry farms were sequenced and compared with other IBV strains. Based on nucleotideidentity, the N gene and 3' UTR sequences of Iranian IBVs showed 90% similarity to the commonly used IBV vaccine strains, H52 and H120.However, based on phylogenetic analyses, Iranian IBVs were found to cluster separately from the IBV vaccine strains used in Iran as well as other IBVs isolated in China, Australia and the United States. It was concluded that IBVs circ ulating in Iran are genetically distinct from IBV vaccinestrains that have been used in Iran for many years. Therefore, it is important to develop a new vaccine based on these newly identified strains forcontrolling IBin Iranian poultry farms

Infectious bronchitis virus; polymerasechain reaction; sequencing; nucleocapsidgene; 3' untranslated region