Ikeda J S, Hirsh D C
Department of Veterinary Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis 95616.
Vet Microbiol. 1990 Mar;22(1):79-87. doi: 10.1016/0378-1135(90)90126-g.
Experiments were performed to test the hypothesis that possession of the same nonconjugative R plasmid by different isolates of Pasteurella multocida implied that they were of the same clone. Seven isolates of P. multocida were studied, two possessed an identical nonconjugative R plasmid (pVM109), four possessed another (pVM110), and one isolate possessed a nonconjugative R plasmid related to pVM110. Phenotypic and genotypic characteristics of the isolates were determined and compared. Isolates possessing the same nonconjugative R plasmid were shown to be different, and isolates possessing a different nonconjugative R plasmid were shown to be the same. We conclude that possession of an identical nonconjugative R plasmid by two isolates of P. multocida does not imply clonality.
