Detection, Elimination, and Prevention of Contamination of Cell Cultures With Pleuropneumonialike Organisms

Recent reports indicate that a number of established cell lines in various laboratories throughout the world are contaminated with pleuropneumonialike organisms (PPLO) (Robin-son et al., 1956; Collier, 1957; Rothblat and Morton, 1958). The contamination is insidious and is difficult to detect for the following reasons: (a) the microorganisms may fail to affect overly the cultures, or they may induce cytopathogenic changes irregularly, (b) the PPLO may reach a very light or no visible turbidity in liquid media, (c) the contaminants are often missed on agar plates because of their minute colony size, and (d) many PPLO are resistant to penicillin and streptomycin, the antibiotics most commonly