Comparative study of the phosphatase activity of typhoid bacilli of varied virulence

Abstract

The investigation covered three genetically associated cultural groups, which included the following strains: 1) ty2 and ty2-trypaflavine, an avirulent mutant devoid of the Vi-antigen, derived from the first under the effect of trypaflavine; 2) ty58-(Panama) and its rough avirulent variants 58R; 3) tyB and the mutants Bc4 and Bc4M derived from it and resistant to streptomycin, varying by their virulence. It was demonstrated that all of the strains of the above bacteria break down sodium Betaglycerophosphate at pH=6, at a relatively high rate. The highest enzyme activity was found to be common to the strain tyB and to the variants derived from the latter. No differences in the phosphatase activity of virulent and avirulent bacterial cultures of the typhoid bacillus could be found after comparing strains of different origin, or genetically related strains.