Some new observations bearing on the nature of the pleuropneumonia-like organism known as L1 associated with<i>Streptobacillus moniliformis</i>

Abstract

The new data presented show that the life cycle of the L1 organism separated from cultures of Streptobacillus moniliformis corresponds in many respects to that of pleuropneumonia. It seems therefore justifiable to classify it with the group of pleuropneumonia-like organisms and not with the bacteria. Its peculiar life cycle, including the formation of elementary reproductive corpuscles, a process previously described for pleuropneumonia, but not occurring in bacteria, is regarded as strong evidence in favour of the conception that Str. moniliformis is composed of two genetically different microbes, a Streptobacillus and the LI organism. Cross-absorption tests between Str. moniliformis and the LI organism have shown that these organisms possess different serological affinities.