molecular detection and histopathological study of mycoplasma gallisepticum in broiler chickens with respiratory lesions in ahvaz slaughterhouse

Mycoplasmosis is one of the important diseases in the poultry industry. mycoplasma gallisepticum is important in causing losses in industrial poultry farms. according to this fact, this study was conducted to perform a survey on mycoplasma infection on broiler chicken farms using molecular methods and histopathology measures. for this purpose, 200 samples of lung and trachea tissues were collected from 20 broiler flocks with macroscopic symptoms and 20 samples from the mentioned parts from apparently healthy broiler chickens of each flock in the winter season. tissue dna extraction was performed. the polymerase chain reaction (pcr) was performed by using specific primers to detect 16srrna gene of mycoplasma gallisepticum. for histopathological examination, tissue sections were prepared from the pcr-positive samples of lung and trachea tissue. the results of the molecular investigation showed that mg were detected in 40 percent of the flocks and out of 200 lung samples, 20(%10) samples were positive for mycoplasma gallisepticum. out of 20 lung samples of apparently healthy chickens 2(%10) samples were positive for mycoplasma gallisepticum. there were no positive cases for the presence of mycoplasma gallisepticum in the tracheal tissue of sick and apparently healthy chickens. the results of histopathology investigations showed that pathological lesions were observed in all lung samples whose pcr was positive for the presence of mg bacteria. in these lungs there are lesions such as lymphocytic pneumonia (%100), granulomatous pneumonia (%11/11), suppurative bronchopneumonia (%6/2). and out of 45 trachea samples of sick chickens and 4 trachea samples of apparently healthy chickens, lymphocytic tracheitis were observed in all cases. the findings of this research indicate the presence of mycoplasma contamination in flocks of broiler slaughtered in ahvaz slaughterhouse and lymphocytic pneumonia is the main microscopic lesion.