Serological detection of Mycoplasma gallisepticum, Mycoplasma synoviae and Mycoplasma melleagridis in free range chickens in Ilorin, Kwara State

This study was designed to detect the three mycoplasmas from free-range chickens using the diagnostic confirmatory supports from Animal and Plant Health Agency, UK. Out of 602 serum samples screened with rapid serum agglutination test (RSAT), 33 were positive for both Mycoplasma gallisepticum (Mg) and Mycoplasma synoviae (Ms). The 33 positive sera and 11 cultures with typical fried egg appearance suggesting mycoplasma organism were submitted to the Animal and Plant Health Agency (APHA), UK for confirmation using RSA (different antigen batches) and commercial ELISA tests, based on manufacturers interpretative criteria, specific for each of the three species’ antibodies as well as re-cultivation and denaturing gradient gel electrophoresis PCR-DGGE as well as real-time (Mg/Ms combination) on the submitted stored cultures. Rapid serum agglutination test for the three species were used with associated positive control sera, typically showing 2+ or 3+ reactions for the correct antigen, with no obvious reaction for the negative sera. ELISA data revealed 21 of the 33 samples to be positive for Mg, 19 positive for Ms and 14 for both. Two samples were also positive for Mycoplasma melleagridis (Mm) by ELISA. The difference between the RSAT and ELISA findings may be associated with the ability of the RSAT to detect antibody response to exposure at an earlier stage than ELISA. Of the six cultures tested, none was positive for Mg or Ms. PCR-DGGE, confirmed the real-time PCR results with many bands. Further serological testing has confirmed the presence of antibody response to Mg and Ms in a high proportion and indicating likely exposure of free- range chickens to these avian pathogens.