Properties of some new Brucella phage isolates; evidence for lysogeny within the genus.

A number of phages were isolated from Brucella abortus strains showing atypical phage sensitivity patterns. The phages, designated the Firenze group, were all similar in morphology, host range general properties. They were lytic for smooth Brucella abortus, Br. neotomae and Br. suis, but not for Br. melitensis strains. They were serologically distinct from phages of the Tbilisi and M51-S708-Weybridge groups and also differed from these in plaque morphology and physical and chemical stability. The parent brucella strains although smooth were resistant to lysis by their own phages or by the other available brucella phages. Their general properties suggested a lysogenic state.