MOLECULAR EPIDEMIOLOGY OF VIBRIO-CHOLERAE O1 ISOLATED IN NEPAL BY SOUTHERN HYBRIDIZATION WITH A CHOLERA-TOXIN GENE PROBE

A cholera epidemic broke out in 1992 due to Vibrio cholerae O1 biotype El Tor in the eastern and southern belt of Nepal mainly among the Bhu tanese refugees. Restriction fragment profiles (RFP) of DNA fragments of V. cholerae O1 isolates hybridized with an enzyme-labelled oligonuc leotide probe for cholera toxin gene (ctx) by Southern Hybridization w ere compared. The probe hybridized with the 13- and 8-kb fragments of PstI-digested total DNA in all isolates observed in the epidemic. This RFP in the Nepalese strain was not observed in the strains isolated d uring other epidemics but was observed in the strains isolated from th e exported marine products from Taiwan and Thailand.