فهرست مطالب waleed seger

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.

Avian infectious bronchitis (IB), with avian infectious bronchitis virus (IBV) as the causing agent, is a ubiquitous endemic disease of the chicken with devastating effects on its industry. A viral membrane surface protein called S not only induces neutralizing antibodies but also plays an important role in virus binding and entry to host cells. Technically, S1 protein gene sequencing also helps greatly in IBV genotyping.
The aim of this study was to characterize Iranian IBV based on S2 gene.
After RT-PCR amplification, the S2 gene of nine Iranian IBV isolates were sequenced and then compared with reference strains.
The isolates were classified into genotype I as Massachusetts like IB Vs, genotype VII which clustered into two branches, VIIa (IS-1494 like IB viruses), and VIIb, and was related to QX- like viruses and Genotype VIII as 793/B like IBVs.
As far as we know, this is the first S2-based classification study on Iranian IBV isolates providing a firm experimental basis to correlate with genotypic characterization

Avian infectious bronchitis (IB) has prevalent in the most chicken farms during recent years, in spite of the IB vaccination program which has been widely performed in Iran. To better understand the molecular epidemiology of IBV in Iran, the full length sequences of S1 gene of Iranian QX IBVs were determined and phylogenetic analysis was done using some sequences of IBV.
To better understand the molecular epidemiology of IBV in Iran, the full length sequences of S1 gene of Iranian QX IBVs were determined and phylogenetic analysis was done using some sequences of IBV.
Iranian QX IBVs were located in LX4 (Cluster 2). The nucleotides homologies were 99.52% - 100% between the isolates. Phylogenetic analysis revealed that all the IBV isolates were very similar and probably had a common origin. The hyperactive variable regions of S1 were determined.
The results from this study and other published results in the GenBank database showed that the isolates circulating in Iran in recent years were mainly LX4 (Cluster 2) genotype, which is the predominant genotype circulating in Iran in recent years (After first report of QX IBV in Iran, 2011). This finding provides important information on IBV evolution in Iran.