RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISM OF THE PMJ101-LIKE PLASMID AND RIBOTYPING IN THE FISH PATHOGEN VIBRIO-ORDALII

A total of 32 Vibrio ordalii strains were studied for their plasmid co ntent and shown to carry a plasmid of approximately 32 kb. This plasmi d was subsequently subjected to restriction fragment length polymorphi sm (RFLP) studies. Using Hind III, three different restriction pattern s were identified while BamHI cleaved the plasmid into a single linear fragment. The results suggest that the 32 kb plasmid is highly conser ved but that some variation in restriction pattern occurs. The same se t of strains was subjected to ribotyping. Using Mill I, six different restriction patterns were demonstrated. Strains from the USA and Canad a shared profiles with strains from Australia and Japan. Strains from Australia generated a single pattern whereas strains from North Americ a were subdivided into three patterns, and the Japanese strains fell i nto five patterns. The results suggest that ribotyping in combination with RFLP studies of the pMJ101-like plasmid may be useful in epidemio logical studies of V. ordalii.