Isolation of bacteriophages from Listeria monocytogenes Serovar 5 and Listeria innocua.

11 new bacteriophages, 3 from Listeria monocytogenes serovar 5 and 8 from Listeria innocua were isolated from lysogenic strains without induction. Phagovar determinations were carried out with these phages and 12 other isolated from L. monocytogenes serovars 1/2 and 4b. 76% of the 142 strains from different serovars tested gave a lytic pattern. The new phage set increased the percentage of determinable L. innocua strains to 61.7%. Different phage patterns underline the distinction between L. monocytogenes and L. innocua. L. monocytogenes serovar 5 is characterized by its great sensibility to many phages from lysogenic strains of various serovars.