Biological Activity of a Residual Form of Streptomycin against Eberthella typhosa.

The sensitivity of E. typhosa to a residual fraction of streptomycin obtained during the purification process is at least 2 to 5 times greater than to the crystalline CaCl2 double salt of streptomycin. By the Oxford cup plate method, the E. typhosa-Be. subtilis (or E. colt) differential ratio of this material is approximately 2.0-3.0. This residual streptomycin is active in vivo as well as in vitro. Its activity in vivo is not as great, however, as might be anticipated from the in vitro results.