Antigens of Micropolyspora faeni strains.

Exocellular antigens from Micropolyspora faeni and Micropolyspora rectivirgula were prepared by growing them in a synthetic broth culture at 50 degrees C for 1 week under continuous shaking. The broth was separated from the organisms by filtration and the filtrate was dialyzed and freeze-dried. The cross-reactivity of these antigens were studied by antigen-antibody crossed-immunoelectrophoresis and the presence of similar antigens in different strains by tandem crossed-immunoelectrophoresis using rabbit anti-M. faeni and anti-M. rectivirgula sera. The results indicate that a number of antigenic components are common to the different strains of M. faeni and M. rectivirgula, while each strain demonstrates several specific antigenic determinants. Of the 26 clearly demonstrable precipitin arcs formed by crossed-immunoelectrophoresis, only 1 was detected in all the strains while 2 more were detected frequently. This study indicates that M. rectivirgula and M. faeni strains are not distinguishable from each other by morphological, biochemical or immunological criteria.