Comparative enzyme studies of Escherichia Coli and other enteric bacteria

Three hundred and fifty seven cultures of enteric bacteria comprising the genera Escherichia, Enterobacter, Klebstella, Citrobacter, Shigella, Salmonella, Proteus, Serratia, Yersinia, and Pseudomonas aeruginosa were studied for their abilities to agglutinate animal ery- throcytes and to synthesize proteases, phospholipases, phosphatases, DNases, RNases, ATPases and cAMPase. In general, EF. coli serotype strains were found to be more active enzymically, especially in cAMPase, than the nonserotype strains. However, only 16 of 136 E. eoli serotypes, 12 of 26 strains of Pseudomonas aerugin- osa, 6 of 14 strains of Proteus mirabilis, 2 of 4 strains of Proteus vulgaris, all 7 strains of Proteus morganti, all 3 cultures of Serratia species and 4 species of Salmonella have demonstrated activities of all groups of enzymes mentioned. On the other hand, the members of the genera Enterobacter, Shigella, Yersinia, and the majority of Salmonella species revealed activities of certain enzymes only. The Salmonella organisms showed very strong RNase activities, and Shigella species were very active in acid (pH 5.6) ATPase, and protease. Possible roles of the listed enzymes in pathogenicity of enteric bacteria are briefly discussed.