Plasmid profiles of Shigella and Salmonella spp. isolated from diarrhoeic humans in Ibadan, Nigeria.
Clinical isolates of Shigella flexneri, S. dysentariae, S. boydii and Salmonella spp. were screened for the presence of plasmids. Most of the isolates harboured more than one plasmid ranging in molecular size from 1.3 to 36.1 x 10(6) daltons. Very large plasmids were not encountered.