Detection of virulence factors of Mycoplasma gallisepticum (MG), isolated from broilers with chronic respiratory disease, using Real-time PCR High-Resolution Melting Curve technique

Mycoplasma gallisepticum (MG) is a bacterial pathogen that causes chronic respiratory disease (CRD) in poultry. CRD not only reduces productivity in poultry farms but also leads to significant economic losses in the poultry industry. Molecular methods have emerged as a reliable tool for the diagnosis of this bacterial infection. The aim of this study was to identify virulence factors of Mycoplasma gallisepticum isolated from chickens with respiratory diseases using Real-time PCR High-Resolution Melting curve (HRM) technique. In general, 50 broiler farms were included in this study. 20 samples were collected from each farm. DNA extraction was performed using CTB i-genomic DNA extraction kit. From 50 farms where samples were collected, four farms were identified as Mycoplasma positive using Real-time PCR method. The melting curve was performed with high-resolution real-time PCR and the obtained data were analyzed using the PCR max system. PCR results showed that pvpA, crmA and gapA genes were present in these samples, the results of phylogenetic tree drawing were compared with similar samples in previous studies. HRM analysis reveals molecular diversity between isolates. The results of this study showed that the use of HRM Real-time PCR is a reliable method to identify and investigate the presence of virulence factors related to the Mycoplasma pathogen.Keywords: Mycoplasma gallisepticum, Chronic respiratory disease, Poultry, Virulence gene, HRM Real-time P