CHARACTERIZATION OF 16 CAMPYLOBACTER-JEJUNI AND CAMPYLOBACTER-COLI TYPING BACTERIOPHAGES

Taxonomic classification of bacteriophages specific for Campylobacter jejuni and C. coli has not been reported previously. A set of 16 virul ent phages, distinguishable by their lytic spectra, has been used exte nsively for epidemiological typing of C. jejuni and C. coli at Preston Public Health Laboratory. These phages were investigated by electron microscopy, pulsed-field gel electrophoresis and restriction endonucle ase analysis. All phages had icosahedral heads and long contractile ta ils. Accordingly, they were classified as members of the Myoviridae fa mily. These phages could be subdivided into three groups according to genome size and head diameter: group I, two phages with head diameters of 140.6 and 143.8 nm and genome sizes of 320 kb; group II, five phag es with average head diameters of 99 nm and average genome sizes of 18 4 kb; and group III, nine phages with average head sizes of 100 nm and average genome sizes of 138 kb. Phages NCTC12676 and NCTC12677 of gro up I had unusually large genomes of c. 320 kb which are two of the lar gest phage genomes to be described. Restriction endonuclease analysis demonstrated that DNA from the 16 phages was refractory to digestion b y a number of restriction enzymes.