Development of the novel Pictor PictVet™ Mycoplasma bovis IgG multiplex ELISA for the detection of Mycoplasma bovis infections in cattle

Early and accurate detection of infection with <i>Mycoplasma bovis (M. bovis)</i> is critical for managing disease caused by this pathogen, particularly in eradication campaigns, such as New Zealand's National <i>M. bovis</i> Eradication Programme. In response to the launch of the eradication programme, we developed and evaluated a novel multiplex ELISA assay-the Pictor PictVet™ <i>M. bovis</i> IgG Multiplex ELISA. Two <i>M. bovis</i> antigens, MilA and K310, were incorporated into the Pictor PictVet™ <i>M. bovis</i> Multiplex ELISA to detect <i>M. bovis</i>-specific serum IgG. Studies were conducted to determine the assay agreement with the ID Screen® <i>Mycoplasma bovis</i> Indirect ELISA (IDvet). A collection of sera from New Zealand cattle, previously characterized as IDvet-positive (+) and IDvet-negative (-), was used for these evaluations. Binding to the two different <i>M. bovis</i> antigens, MilA and K310, had high estimates of agreement, with PPAs of 89.3 and 96.4%, and a NPA of 99.2%. When the results from both the MilA and K310 components of the assay were combined to determine the assay outcome, the PPA increased to 100%, while the NPA remained high, at 98.4%, with an overall agreement of 98.9%. Multiplexing of two <i>M. bovis</i> antigens enhanced the diagnostic performance of the indirect ELISA in detecting <i>M. bovis</i>-specific IgG in serum samples. These findings suggest that the Pictor PictVet™ <i>M. bovis</i> IgG Multiplex ELISA could be a valuable tool for early detection and surveillance for infection with <i>M. bovis</i> in cattle.