Identification of Mycoplasma felis and Mycoplasma gateae by an immunobinding assay

An immunobinding assay capable of distinguishing between Mycoplasma felis and Mycoplasma gateae was developed. Nitrocellulose was used as the solid support. Polyclonal rabbit antiserum against M. felis or M. gateae was used in the assay. Binding of the specific rabbit antiserum was detected by alkaline phosphatase-conjugated goat anti-rabbit immunoglobulin and an alkaline phosphatase substrate (Nitro Blue Tetrazolium-5-bromo-4-chloro-3-indolyl phosphate). The immunobinding assay was effective in the detection of feline mycoplasmas on agar plates, on primary isolation plates, in broth cultures, and in mixed cultures. No cross-reactions were observed with other related mycoplasmal species. The assay was cheap to perform and easy to interpret, and it required little technical time.