Differences between Oral and Genital Strains of Human Pleuropneumonialike Organisms. ∗,†

Conclusion and Summary

Pleuropneumonia-like strains isolated from the human genitourinary tract and from the buccal cavity, respectively, differ in the appearance of the colonies, in serological properties and, to a certain extent, in nutritional requirements. It is likely that they represent different species. In addition to the easily cultivatable strains, colonies of much smaller size develop occasionally on the plates inoculated from either source. These small colonies retain their identity in transfer. It is uncertain whether they are variants of the usually cultivated strains.