Use of MSG1 protein in a novel blocking ELISA for the detection of Mycoplasma suis infection

A blocking ELISA based on the monoclonal antibody (MAb) 1A7 was developed to detect antibodies against Mycoplasma suis. The MAb was produced by immunising BALB/c mice with recombinant MSG1 protein (rMSG1) from M. suis expressed in E. coli. Following identification by Western blotting, the MAb was purified and labelled with horseradish peroxidase. The parameters of the ELISA were optimised, and the cut-off value determined as 36.35% by analysing the percentage inhibition of M. suis negative serum. The sensitivity and specificity of the ELISA were 92% and 100%, respectively. In repeatability tests, the intra- and inter-batch variation coefficients were <10%. The results suggest this blocking ELISA is specific, sensitive and reproducible, and will be a valuable tool in the serodiagnosis of M. suis infection in pigs.