HEMOLYSIN OF MYCOPLASMA PNEUMONIAE.

Somerson, Norman L. (National Institute of Allergy and Infectious Diseases, Bethesda, Md.), Robert H. Purcell, David Taylor-Robinson, and Robert M. Chanock. Hemolysin of Mycoplasma pneumoniae. J. Bacteriol. 89:813-818. 1965.-Discrete colonies of Mycoplasma pneumoniae or M. laidlawii on agar produced complete (beta) lysis of guinea pig erythrocytes. Crowding of colonies on agar plates, omission of yeast extract from the medium, and incubation under reduced oxygen tension inhibited hemolysin production. Colonies which were not viable after ultraviolet radiation or heating at 56 C did not produce hemolysin. In addition, hemolysis was suppressed in old cultures in which viability was diminished, and was eliminated when colonies were removed from the agar surface by micromanipulation. The hemolysin passed through a viscose dialysis membrane. These findings suggest that the hemolysin is labile, continuously released by the colonies, of low molecular weight, and probably nonprotein in nature.