الفهرس 
AbstractOnly 14 pages are availabe for public view
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Abstract
Mycoplasma gallisepticum is an important avian pathogen causing significant economic losses within the poultry industry. One of the options for controlling MG infection is live MG vaccines. Differentiation between field and vaccinal strains is important for determining the source of the infection, recognizing particularly virulent strains, and monitoring vaccination programs. In this study we used mgc2, MGA0319 genes real time PCR assays to detect MG to be furtherly tested by mgc2 rt-PCR for F, 6/85 and TS-11 strains. The detection limits for mgc2 cPCR was 70 CFU/ml. However, those of MGA0319 gene, mgc2 gene, F, 6/85 and TS-11 rt-PCR were 50, 14, 18, 12 and 20 CFU/ml, respectively. All the PCR assays were specific for its related strains. Out of 84 MG vaccinated and unvaccinated poultry farms, 36 were positive for MG, from which 16 were positive for F strain and 11 were positive for 6/85 strain, while 9 farms were MG positive but negative for live vaccine rt-PCR. DNA nucleotide sequencing for 20 positive cases for mgc2 gene confirmed the rt-PCR results and grouped the nucleotides sequenced samples into 4 groups (F, 6/85 and two field strain groups named field group A and B).