| molecular characterization of environmental and nontoxigenic strains of vibrio cholerae. | environmental and nontoxigenic strains of vibrio cholerae 0-1 were examined for genes homologous to genes encoding escherichia coli heat-labile enterotoxin (lt). restriction fragments encoding lt a and b subunits were isolated from the recombinant plasmid ewd299 and labeled in vitro with 32p. these probes were then hybridized to deoxyribonucleic acid extracted from strains of v. cholerae and visualized by autoradiography. none of the nontoxigenic strains of v. cholerae 0-1 from louisiana, alabam ... | 1981 | 7251142 |