The aim of the study was to evaluate the presence of Mycoplasma bovis infection and co-infections with other Mycoplasma spp. infections in cattle. The tested population was one in the eastern region of Poland containing 66 dairy cows and 23 calves showing different clinical signs and suffering from pneumonia, mastitis, and arthritis. The incidence of M. bovis in co-infections with other Mycoplasma spp. was examined using serological traditional mycoplasma culture methods, and the molecular methods - PCR and polymerase chain reaction/denaturing gradient gel electrophoresis (PCR/DGGE). The PCR/DGGE method for detecting Mycoplasma spp. in cattle was used for the first time in Poland. The seroprevalence of M. bovis in the affected cattle herds in the eastern region of Poland was 47.8% in calves and 19.7% in dairy cows. The direct detection and identification of M. bovis from nasopharyngeal swabs by PCR revealed that 56.5% of calves were positive, but all of the dairy cows were negative. The PCR/DGGE identified eight (34.8%) instances of M. arginini and eight (26.1%) instances of M. bovirhinis co-infecting with M. bovis in ten calves. The seroprevalence of M. bovis in the tested population was 33.7%. Any future attempts to control mycoplasma infections require an insight into the current epidemiological situation of M. bovis infection and its relationship to other mycoplasmas in causing clinical disease in cattle. Using these diagnostic methods we have demonstrated that mycoplasmal infections are often caused by multiple species of Mycoplasma and not just the primary M. bovis pathogen.
