Molecular and Seroprevalence of <i>Mycoplasma gallisepticum</i> in Turkeys in Sylhet District of Bangladesh

Mycoplasma gallisepticum (MG) poses a significant threat to Bangladesh's poultry industry, causing substantial economic losses every year. This study aimed to determine the prevalence of MG infection in turkeys using serum plate agglutination (SPA), enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) in Sylhet, Bangladesh from December 2019 to November 2020. In addition, we evaluated the diagnostic accuracy of these tests and identified potential risk factors associated with MG infection. A total of 250 blood samples and 250 tracheal swabs were collected from suspected turkeys across 25 farms from three sub-districts of Sylhet namely Sylhet Sadar, Golapganj and Beanibazar. Blood samples were tested with SPA and ELISA, while tracheal swabs were analysed by PCR targeting the 16S rRNA gene of MG. The overall prevalence of MG was 35.2%, 29.2% and 25.6% for SPA, ELISA and PCR respectively. Higher infection rates were observed in turkeys aged 0-4 months (SPA 57.1%, ELISA 52%, PCR 42.8%), during winter (SPA 43.1%, ELISA 37.8%, PCR 30%) and among female turkeys (SPA 54.5%, ELISA 49.5%, PCR 45.5%). Geographically, the Beanibazar had the highest prevalence (SPA 54.2%, ELISA 48.6%, PCR 41.4%), compared to the Sylhet Sadar and Golapganj sub-districts. Both SPA and ELISA tests showed 100% sensitivity, with specificity of 87.1% and 95.2%, respectively using PCR as a gold standard. Overall, these findings provide valuable insights for developing effective control measures for MG infections in the poultry industry of Bangladesh.