Summary.Aspects of the problem of myeoplasma contamination of eell eultures have been examined. Particular attention has been paid to the effective eradication of myeoplasma contaminants. The effects of tylosin, a new antibiotic, are examined in detail.The work also describes attempts to eradicate a particularly resistant strain of M. orale type I, which has been isolated from contaminated cell lines in this laboratory.
INTRODUGTION.In recent years use has been made of cell cultures as a method for the isolation of mycoplasmas from clinical specimens originating from patients with leukaemia, rheumatoid arthritis or Reiter's disease (Murphy and Furtado, 1963; Negroni, 1964;Grace, Horoszewicz, Stim and Mirand, 1963; Grace, Horoszewicz, Stim, Mirand and James, 1965;Bartholomew and Himes, 1964;Bartholomew, 1965). The validity of this technique relies heavily on the methods of detecting mycoplasmas in cell culture so as to ensure that they are free of contaminating mycoplasmas at the time of use.The isolation or detection of myeoplasma contaminants of cell cultures is not an easy matter. Many methods have been proposed for the detection of mycoplasmas in cell cultures. These have included the direct visualization of myeoplasma by staining of contaminated cell sheets (Fogh and Fogb, 1964; Glyde, 1961), the use of chemical methods based on the presence of arginine dehydrolase in mycoplasmas (Barile and Schimke, 1963;House and Waddell, 1966) and the culture of supernatant fluid or disrupted cells in suitably supplemented agar medium. Methods of detection of myeoplasma in cell cultures have been reviewed in detail by Hayflick (1965).