Comparative evaluation of diagnostic assays with clinical signs for detection of Mycoplasma synoviae infection in commercial layer chicken

The study was conducted for correlation of clinical signs of M. synoviae with different diagnostic tests such as indirect-ELISA, bacterial culture and PCR assay. Eighteen commercial layer farms which indicated M. synoviae infection by showing clinical signs such as leg weakness, reduction in egg production and eggshell apex abnormalities, were subjected for indirect ELISA, culturing and PCR tests. Sera samples were collected for indirect ELISA, choanal cleft swabs for M. synoviae culture and direct PCR assay. All the 18 tested farm samples irrespective of age group were positive in indirect ELISA, 14 were positive in PCR and only six were positive in culture. These findings showed that there was correlation between the clinical signs of M. synoviae infection and ELISA followed by PCR and culture. Hence, it is indicated that indirect ELISA and PCR can be effectively used for screening of M. synoviae infected flocks in comparison to bacterial culture.