Phage typing of Vibrio cholerae 01 biotype ElT or strains.

Data accumulated over the past 20 yr (1969-88) on the phage typing of V. cholerae 01 biotype ElT or strains received at the Vibrio Phage Reference Laboratory, were retrospectively analysed to ascertain the frequency of occurrence of the different phage types of Basu and Mukerjee typing scheme. The analysis revealed that phage types 2 and 4 were the most common types not only at the time when the Basu and Mukerjee typing scheme (of 1968) was introduced but also at present. The existing phage typing scheme needs to be improved with the addition of more new phages to obtain more type distinction and better discrimination within biotype ElT or strains for epidemiological studies.