CoVetLab: Working together to strengthen collaboration on Mycoplasma bovis and compare available diagnostic tools

Summary

Background: Different clinical presentations of disease caused by Mycoplasma bovis predominate in European countries with significant economic and welfare impacts. M. bovis disease control relies on good husbandry and early diagnosis, but lack of standardised approaches and diagnostic methods applied make comparisons of disease prevalence between countries difficult. Five CoVetLab National Veterinary institutes (SVA, WVBR, VET-DTU, APHA,ANSES) together with RUOKAVIRASTO joined forces to develop a network of scientists and share tools and expertise. Objectives included developing ring trials to evaluate available serological and PCR-based diagnostic tests.Methods: The sensitivity and specificity of two commercial ELISA systems (ID screen® ELISA (IDvet) and BIO K302ELISA (BIO-X Diagnostics)) for serodiagnosis of M. bovis in cattle serum were assessed by inter-laboratory comparison using a randomly blinded panel of bovine sera. Inclusion of Western blot analysis enabled statistical evaluation by latent class analysis. In addition, analytical specificity, sensitivity and comparability of seven different PCR methods used to identify presence of M. bovis organisms were assessed.Results: The ID Screen ELISA showed high agreement with Western blot analysis and performed with higher precision and accuracy than the Bio K302 ELISA, also showing higher sensivity and specificity. In contrast the analytical specificity and overall performance of the different PCR methods was comparable, although limits of detection varied from 10 to 103 CFU/ml to 103 and 106 CFU/ml for the real-time and end-point assays, respectively.Conclusions: CoVetLab has facilitated improved collaboration between veterinary institutes in Europe undertaking M.bovis diagnostics. We believe this inter-laboratory comparison of these ELISAs is the first to include the ID Screen. The comparison of PCR tests has provided reassurance regarding the quality of diagnosis, despite the multiplicity of the methods.