Conjugal transfer of a chromosomal gene determining production of enterotoxin in vibrio cholerae.

Matings between strains of Vibrio cholerae differing in toxinogenicity, nutritional requirements, and antibiotic susceptibilities were performed in order to determine the location of the gene tox that controls production of cholera enterotoxin. Segregation analysis shows that tox is linked to a gene required for histidine biosynthesis. Our data indicate that the tox gene is located on the bacterial chromosome and not on a plasmid in the strains of V. cholerae studied.