The Recovery and Molecular Diagnosis of Mycoplasma gallisepticum Infection in Commercial Poultry Flocks in Egypt

Objectives: The aim of this study to investigate MG in field cases of chronic respiratory disease (CRD) and its tissue distribution in positive cases. Methods: Polymerase Chain Reaction by different approaches was used in comparison to the culture method. The study included 385 birds, from which (1,155) samples of trachea, lung tissue and air sacs were collected from different farms of Layers, broilers and Breeders flocks located in seven governorates. Findings: Three detection methods of MG revealed that, the highest recovery rate of MG was achieved by PCR on 48 hours incubation PPLO broth (70.9%), followed by direct PCR on infected tissue (65.45%). The lowest recovery rate was for conventional cultivation method (17.66%) indicating that PCR is more sensitive. On the other hand tissue distribution pattern of MG showed higher percentage from trachea followed by air sacs then lung. Application: The PCR is superior to culture as it is rapid and sensitive for diagnosis of MG, which is compatible with surveillance and control programs of MG. Regarding tissue distribution pattern the trachea has a more privilege during diagnosis of MG infection.