Genotyping of infectious bronchitis viruses from broiler farms in Iraq during 2014-2015.

Infectious bronchitis virus (IBV) is one of the most critical pathogens in the poultry industry, causing serious economic losses in all countries including Iraq. IBV has many genotypes that do not confer any cross-protection. This virus has been genotyped by sequence analysis of the S1 glycoprotein gene. A total of 100 tracheal and kidney tissue specimens from different commercial broiler flocks in the middle and south of Iraq were collected from September 2013 to September 2014. Thirty-two IBV-positive samples were selected from among the total and were further characterized by nested PCR. Phylogenetic analysis revealed that isolates belong to four groups (group I, variant 2 [IS/1494-like]; group II, 793/B-like; group III, QX-like; group IV, DY12-2-like). Sequence analysis revealed nucleotide sequence identities within groups I, II, and III of 99.68 %-100 %, 99.36 %-100 %, and 96.42 %-100 %, respectively. Group I (variant 2) was the dominant IBV genotype. One Chinese-like recombinant virus (DY12-2-like) that had not been reported in the Middle East was detected. In addition, the presence of QX on broiler chicken farms in the area studied was confirmed. This is the first comprehensive study on the genotyping of IBV in Iraq with useful information regarding the molecular epidemiology of IBV. The phylogenetic relationship of the strains with respect to different time sequences and geographical regions displayed complexity and diversity. Further studies are needed and should include the isolation and full-length molecular characterization of IBV in this region.

Prevalence of avian infectious bronchitis virus in broiler chicken farms in south of Iraq, 2014 - 2015.

Avian infectious bronchitis (IB), caused by a gammacoronavirus, is an OIE-listed (List B) disease and characterized by respiratory and renal involvements, causing high mortality, and economic loss in both layers and broilers. In comparison with other diagnostic methods, real-time polymerase chain reaction (RT-PCR) and conventional RT-PCR are potent, more sensitive and faster techniques for infectious bronchitis virus (IBV) detection. This research was conducted to detect IBV using specific primers of IB in three governorates (Basra, Thi-Qar and Muthana) in the south of Iraq. Tracheal specimens were collected from 46 IB suspected commercial broiler flocks. XCE2+ and XCE2- Primers, which amplify all IBV serotypes, were used. Primers MCE1+, BCE1+ and DCE1+ were used to amplify the specific nucleotide sequences of Massachusetts, 793/B and D274 genotypes, respectively. The results of real-time RT-PCR of this study showed that 34 (74.00%) out of 46 infected flocks were positive to IBV. The results of nested PCR showed that 50.00% and 5.89% of positive samples were belonged to genotypes 793/B and Massachusetts, respectively, and the remaining positive (44.11%) were unknown. The results indicate presence of Massachusetts and 793/B IBV strains in commercial broilers in southern Iraq.