Molecular characterization of Vibrio cholerae O1 strains isolated in Romania

A collection of 89 Vibrio cholerae O1 strains, isolated in Romania between 1977 and 1994, and 6 strains from the Republic of Moldavia, was characteriz ed by ribotyping, toxin gene restriction pattern (toxinogenotype) and distr ibution of cholera toxin gene (ctx), accessory toxin gene (ace) and zonula occludens toxin gene (zot). After Bg/l endonuclease restriction of chromoso mal DNA, a total of 18 ribotypes and 21 toxinogenotypes were distinguished. Deletions in the core region of the toxin gene cassette were found in 20% of strains; however, with the exception of one strain, all the isolates con tained the ctx gene. Used in association, the three methods of molecular ty ping provided an accurate characterization of V. cholerae O1 isolates.