Genetic studies on the development of streptomycin resistance in Pasteurella pestis.

Meyer and Quan (1949) have demonstrated amply the therapeutic efficacy of streptomycin in experimental bubonic and pneumonic plague. Since streptomycin appears to be unique among the antibiotics in that high levels of resistance may occur in bacteria at a single mutational step (Bryson and Demerec, 1950), the occurrence of strains of Pasteurella pestis so resistant to this antibiotic as to be refractory to therapy would represent a major problem in the treatment of plague, especially in endemic areas. Consequently, a study of the factors underlying the efficacy of streptomycin therapy in plague as well as the probability of the occurrence of streptomycin resistance during the course of such therapy was undertaken.