Comparison of serological, molecular and cultural diagnostic methods for the detection of Mycoplasma bovis infections in cattle*

Previous studies on Mycoplasma bovis in Poland have used serological methods and culture to isolate the causative organism. PCR and PCR/DGGE molecular tests, antigen ELISA, culture, and antibody ELISA methods were evaluated on 713 animals from 73 Holstein-Friesian herds in Poland with suspected M. bovis infections. The prevalence of M. bovis antibodies in cattle sera was 10.8%. Antigen detection from nasopharyngeal swabs was lowest with the specific PCR having the lowest number of positive samples 39 (5.5%), followed by culture 49 (6.9%), antigen ELISA 52 (7.3%) and PCR/DGGE 66 (9.3%). Statistical analysis showed that all of the methods had high correlation but the antibody ELISA had the lowest level of comparability with each of the other methods. The correlation between clinical signs indicating possible M. bovis infection and test positivity confirmed that clinical signs are not pathognomonic. Statistical analysis revealed that the stronger the positive result in the antibody ELISA the more likely it was to detect M. bovis by PCR and PCR/DGGE.