Characterization of enterocoliticin, a phage tail-like bacteriocin, and its effect on pathogenic Yersinia enterocolitica strains

Yersinia enterocolitica 29930 (biogroup 1A; serogroup O:7,8) produces a bac teriocin, designated enterocoliticia, that shows inhibitory activity agains t enteropathogenic strains of Y. enterocolitica belonging to serogroups O:3 , O:5,27 and O:9. Enterocoliticin was purified, and electron micrographs of enterocoliticin preparations revealed the presence of phage tail-like part icles. The particles did not contain nucleic acids and showed contraction u pon contact with susceptible bacteria. Enterocoliticin addition to logarith mic-phase cultures of susceptible bacterial strains led to a rapid dose-dep endent reduction in CFU. Calorimetric measurements of the heat output of cu ltures of sensitive bacteria showed a complete loss of cellular metabolic a ctivity immediately upon addition of enterocoliticin. Furthermore, a dose-d ependent efflux of K+ ions into the medium was determined, indicating that enterocoliticin has channel-forming activity.