[Differentiation of swine-Mycoplasma by latex-agglutination (author's transl)]

The strains of Mycoplasma were grown in Shittlestone medium for 3-5 days. After centrifugation and washing, the mycoplasm were freeze-dried and stored at -20 degrees C. From this stock material immune sera and antigens were prepared. The immune sera were prepared by immunization of rabbits with a suspension of mycoplasma (2,2 mg dry weight per ml) and complete Freund's adjuvant. For the first immunication, 6.6 mg of antigen were injected into rabbits at different sites. 3 weeks later the second immunization followed by the intramuscular route (4.4 mg of antigen). The third and fourth immunizations were identical to the second one. Antiserum was obtained as usual. In order to avoid unspecific reactions in the latex agglutination, 1 ml of antiserum was added for absorption to 200 mg of freeze-dried sterile Whittlestone medium over 2 days at 4 degrees C. Antigen was prepared by ultrasonic disruption of mycoplasma (20 mg dry weight/ml physiological saline) and centrifugation 17300 X g, 30 min). The supernatant was used as antigen. The latex agglutination was performed in 0.1 M borate buffer pH 8,2. For preparation of the latex antigen compound 0.2 ml of a latex suspension (diluted 5 fold with water) were moxed with 0.5 ml of an antigen suspension (diluted 16 fold with buffer). After 10 min at room temperature, 4.3 ml of borate buffer were added. After 10 min, 0.3 ml of this solution were added again each to 0.3 ml of serial dilutions of anitserum. The suspensions were mixed and left for 20 h at 37 degrees C and after this time for 1 h at room temperature. Then the reactions were read.

M. suipneumoniae and M. hyopneumoniae were found to be identical or very close related strains. Between M. hyorhinis and M. sp. E9 relationship was noted too. M. granularum was different to all other investigated strains of mycoplasma. All results of Latex agglutination are in agreement with investigations performed with the aid of other serological methods and of electrophoretic separations of cell proteins of these mycoplasma.