Molecular Detection of Avian Infectious Bronchitis Viruses in Live Bird Markets, Gilan Province

Coronaviruses (AvCoV) which include infectious bronchitis virus (IBV) and other bird coronaviruses belong to the genus gammacoronavirus, subfamily Coronavirinae. One of the most prominent representatives of gammacoronavirus genus is infectious bronchitis virus (IBV) which is a highly contagious viral pathogen of chickens causing considerable economic losses to the poultry industry. IBVs mostly affect the respiratory, urinary, and reproductive tracts leading to a substantial drop in production. Backyard poultry in the villages usually share their food and water with free flight birds which puts them at serious risk of disease transmission. Furthermore, the poor hygienic measurements which are often used in backyard flocks make them a potential reservoir for diseases that can be transferred to commercial poultry flocks. Live bird markets (LBMs) which receive live poultry to be resold or slaughtered and sold onsite play a significant role in spreading infectious diseases among the different bird species. In the present study, a number of 354 cloacal swab samples were collected from different bird species from LBMs of Gilan province. Subsequently, after RNA extraction, reverse transcription-polymerase chain reaction (RT-PCR) technique was carried out using specific primers of S1 gene to detect coronavirus infectious bronchitis virus. Two samples from backyard chickens were reported to be positive to coronavirus which were named Iran/Backyardchicken96/2017 and Iran/Backyardchicken94/2017. The results of the phylogenetic analysis demonstrated that these two isolates are placed in QX and IS-1494 strains, respectively. On a final note, the obtained results highlighted the role of live birds offered in LBMs in the epidemiology of IBV and the transmission of the virus to the industrial flock.