Bacteriophages induced from weakly beta-haemolytic human intestinal spirochaetes by mitomycin C

A comparative electron microscopic analysis of weakly beta-haemolytic spiro chaetes related to human and animal intestinal spirochaetosis was done in o rder to search for the presence of inducible bacteriophages associated with these spirochaetes. Bacteriophages were detected at the electron microscop e after experimental induction with mitomycin C in 4 strains of weakly beta -haemolytic spirochaetes related to human intestinal spirochaetosis, in Ser pulina pilosicoli strain P43/6/78, the causative agent of swine intestinal spirochaetosis, in a spirochaetal strain related to avian intestinal spiroc haetosis, and in Serpulina hyodysenteriae, strain P18A, the causative agent of swine dysentery, which was comparatively analysed as control. All phage -particles observed in both human and ani mal intestinal spirochaetes were morphologically similar with an isometric head of 45 nm diameter and a tail 63-70 nm long and 7-12 nm width. The presence of morphologically similar p hages in all the haemolytic intestinal spirochaetes of human and animal ori gin analysed in this study opens some important questions, about the geneti c relationship of phages present in pathogenic intestinal spirochaetes, the ir host range, and the possibility of natural gene transfer among pathogeni c haemolytic intestinal spirochaetes of human and animal origin.