Formation of Bacterial Protoplasts by Serum Components

Summary Normal mammalian serum plus stabilizing agents effected conversion of the viable bacterial rods of Escherichia coli B and Salmonella typhosa Mrs. S., both rough organisms, into spherical protoplasts. A smooth organism, S. typhosa H901, was refractory, however, to the formation of protoplasts by normal serum, but addition of antiserum, complement, and lysozyme led to the formation of stabilized protoplasts of this organism. These protoplasts may conceivably play a role in the persistence of microbes in the animal body.