Suppression of Rous Sarcoma Virus Growth in Tissue Cultures by Mycoplasma Orale.

Somerson, Norman L. (National Institute of Allergy and Infectious Diseases, Bethesda, Md.), and M. K. Cook. Suppression of Rous sarcoma virus growth in tissue cultures by Mycoplasma orale. J. Bacteriol. 90:534-540. 1965.-An agent which produced cell destruction in human diploid and chick-embryo fibroblasts was isolated from WI-26 strain of human diploid fibroblasts and shown to be a mycoplasma. The multiplication of Rous sarcoma virus (RSV) and Rous associated virus (RAV) was inhibited in WI-26, WI-38, and chick-embryo fibroblasts infected with this mycoplasma. The mycoplasma isolate, designated strain 941, reacted strongly in the complement-fixation test with antiserum to Mycoplasma orale CH19299, an isolate obtained from the human oral cavity. The cytopathic effect of mycoplasma strain 941 could be eliminated by growing the mycoplasma on an artificial agar medium before inoculation into chick-embryo fibroblasts. Serial passage in chick-embryo fibroblasts restored the cytopathogenicity of the agar-grown mycoplasma. However, growth of RSV and RAV was inhibited by both the tissue culture-grown and the agar-grown 941 strain, and also by the CH19299 strain which did not produce any cytopathic effect.