A transferable resistance plasmid in Vibrio cholerae and Escherichia coli isolated from the same patient.

This study attempted to determine whether or not resistance plasmids present in Vibrio cholerae and Escherichia coli isolated from the same patient with diarrhoea were identical. Both species were resistant to ampicillin, kanamycin, tetracycline and gentamicin and both species harboured conjugative plasmids of approximately 112 megadaltons belonging to incompatibility group C. The results showed that the resistance plasmids of both organisms appeared to be identical, which confirms that genetic material can be transferred in vivo between organisms of different families. The implications of such a transfer are discussed.