Five surface colony types observed in cultures of cultivable members of the family Treponemataceae.

During the 58 years since Muhlens and Hartmann (1906) first reported the cultivation of anaerobic Treponemataceae in vitro, little has been accomplished in classifying these organisms other than by morphological description. A major obstacle to systematic classification has been the difficulty encountered in cultivating these organisms in general and as surface colonies in particular. Breed, Murray, and Smith (1957) list 38 species of Treponemataceae of which fifteen are said to have been cultivated in vitro. There are no descriptions of colony forms of any of the species. Gates (1923) first described the cultivation from broth culture of four strains or species as surface colonies on blood agar plates incubated in a Brown anaerobic jar. Gates also reported that subculture from surface colonies was not always successful. Other reports citing similar results are those of Fortner (1929), Aksjanzew-Malkin (1933), Wichelhausen and Wichelhausen (1942), and Berger (1958). Socransky, Macdonald, and Sawyer (1959) consistently obtained growth of oral treponemes as surface colonies only in cultures that were inoculated and incubated under strict anaerobic conditions but not in cultures inoculated at the bench under the normal atmospheric environment. It was concluded that exposure to atmospheric oxygen for the brief period required to inoculate the plates and subsequently to establish anaerobic conditions was detrimental to their growth as surface colonies. Hardy, Lee, and Nell (1963) reported that surface colonies were obtained on streak plates with fourteen treponemal strains and one Borrelia strain inoculated under normal atmospheric conditions. Anaerobic conditions were rapidly established after inoculation. They hypothesized that established stock strains had