Dendrogram showing genomic fingerprints of V. cholerae O1 strains isolated in Nepal in 2012.

The fingerprint pattern in the gel was analyzed using a computer software package, Bionumeric (Applied Maths, Belgium). After background subtraction and gel normalization, the fingerprint patterns were typed according to banding similarity and dissimilarity as recommended by the manufacturer. , using the Dice similarity coefficient and unweighted-pair group method employing average linkage (UPGMA) clustering, by using pulsed-field gel electrophoresis (PFGE) images of NotI- restriction digested genomic DNA of the tested Nepalese V. cholerae strains; PFGE images of contemporary V. cholerae O1 El Tor strains from Haiti and Bangladesh, including El Tor reference strain N16961 were also included. The scale bar at the top (left) indicates similarity coefficient. The banding patterns and the similarity coefficient revealed 100% similarity for all the tested Nepalese, Haitian, and Bangladeshi V. cholerae strains included in the dendrogram, suggesting high level of clonal relatedness.