Resistance relationships in Mycobacterium smegmatis ATCC 607 to phages sensitive or resistant to both chloroform and streptomycin sulphate.

Four of eight mycobacteriophages did not form plaques after they were exposed to chloroform. Phages sensitive to chloroform did not produce plaques when plated on media containing 1000 microgram/ml of streptomycin sulphate. The same concentration of dihydrostreptomycin sulphate did not interfere with plaque formation. Mutants of Mycobacterium smegmatis resistant to each of the eight phages were isolated. Sensitivity or resistance to chloroform and streptomycin sulphate and phage resistant bacterial mutants may provide a basis for classifying the mycobacteriophages.