Validity of new phage typing scheme against Vibrio cholerae 01 biotype ElTor strains.

A total of 538 strains of V. cholerae 01 biotype ElTor were phage typed by the conventional Basu and Mukerjee and also the new typing scheme developed at the National Institute of Cholera and Enteric Diseases, Calcutta. The strains could be clustered into seven types by the new scheme as against only two by the conventional method. The results provide conclusive evidence on the validity of the new scheme for phage typing of V. cholerae strains.