Development of a blocking enzyme-linked immunosorbent assay for detection of turkey antibodies to Mycoplasma meleagridis

A blocking enzyme-linked immunosorbent assay (B-ELISA) was developed to det ect antibodies to Mycoplasma meleagridis (MM) in turkey sera. This assay wa s based on two mouse monoclonal antibodies recognising all MM strains teste d but none of seven avian mycoplasmal species tested. Furthermore, their bi nding to the Tween 20 antigen was inhibited by serum from MM-infected birds . The B-ELISA test format was optimized. The cut-off was determined using a set of sera from MM-free turkeys. This B-ELISA was then compared with a co mmercial indirect ELISA (I-ELISA). Specificities of the two ELISA tests wer e not significantly different (100 or 99%, respectively). The sensitivity o f B-ELISA was significantly higher than the I-ELISA when I-ELISA suspicious results were considered as negative. Testing sera from experimentally MM-i nfected animals showed that serum plate agglutination (SPA) test detected p ositive birds before both ELISA methods. Samples were collected in MM-infec ted commercial Rocks and analyzed by SPA, ELISAs, MM-PCR or culture. Result s showed that the sensitivity of the B-ELISA appeared superior to the I-ELI SA. Moreover. the ability to detect maternal antibodies makes it a useful t ool for eradication or control of MM infections. (C) 2001 Elsevier Science B.V. All rights reserved.