[Y. pestis phage of a new serovar].

Phage II, isolated from Y. pestis strain 2247 obtained from a desert focus in Central Asia, has been studied. The phage is classified with moderate phages and essentially differs from moderate phages of serovar 2. The sources of isolation, high specificity and the absence of common serological features with presently known Y. pestis phages of serovars 1 and 2 permit the classification of this phage with new serovar 3 of Y. pestis phages.