USE OF REPRESENTATIONAL DIFFERENCE ANALYSIS TO IDENTIFY GENOMIC DIFFERENCES BETWEEN PATHOGENIC STRAINS OF VIBRIO-CHOLERAE

Representational difference analysis (RDA) is a recently developed tec hnique used for amplifying genetic differences between two closely rel ated genomes. We compared RDA and a modified version of RDA to examine genomic differences between the two Vibrio cholerae serogroups that c ause epidemic cholera, O1 and O139, and between the two biotypes of th e 01 serogroup. With both techniques, we recovered several sequences k nown to be found only in V. cholerae O139 but absent in its presumed p rogenitor, V. cholerae 01 El Tor. A greater number of unique fragments were generated in comparing the two V. cholerae 01 biotypes, consiste nt with the probable greater genetic differences between the two bioty pes.