ABSTRACT
62 strains of Brucella genus, freshly isolated from man and animals in several geographical aereas in Italy, were tested for sensitivity to the phages: Tb. Wb, Fi. BK2 and R. The strains from human source, all classified like Br. melitensis biotype II. had three sensitivity patterns to phages. Some of the strains from cattle are Br. abortus biotype 1, with the standard sensitivity pattern to the phages, but among cattle strains too, the largest part may be classified as Br. melitensis biotype II, and shows the same phage sensitivity pattern of the human strains. The strains from sheep are Br. melitensis biotype II. with only two phage sensitivity pattern; but it is to emphasize that some strains from goats are Br. abortus for sensitivity to phage Tb. It is also note the strains from buffaloes, which are Br. abortus biotype I with a very high degree of sensitivity to all the testes phages, included the R phage. wich is supposed active on rough strains while these are smooth