APPLICABILITY OF RIBOTYPING FOR INTRASPECIFIC CLASSIFICATION AND EPIDEMIOLOGIC STUDIES OF PHOTOBACTERIUM-DAMSELA SUBSP PISCICIDA

The ribotype analysis of a collection of twenty nine Photobacterium da msela subsp. piscicida strains, with different host and geographical o rigins, was performed in order to analyze the possible genetic variabi lity within this bacterial fish pathogen. In addition, the value of th is technique for intraspecific classification and epidemiological stud ies of Ph, damsela subsp. piscicida was evaluated. After restriction w ith four endonucleases, PVuI, PvuII, SmaI, and HindIII, two major ribo types could be established. The first ribopattern compiled the Europea n strains, while the second ribotype included the Japanese isolates. A third ribotype was observed with the enzymes PvuI, SmaI and HindIII, constituted in all cases by an unique strain. Endonuclease PvuI clearl y differentiated the french isolate, while SmaI and HindIII distinguis hed the Israeli strain from tile other European Ph. damsela subsp, pis cicida. The similarities among ribotypes, calculated by the Dice coeff icient, varied from 30-40%, with PvuI and PvuII, to 80-90% with SmaI a nd HindIII. The results obtained indicate the usefulness of the riboty ping procedures for epidemiological studies and also as an important t axonomic tool for the fish pathogen Ph. damsela subsp. piscicida.