[Lysogeny studies of Vibrio cholerae NAG]

To establish the presence of phages specific for V. cholerae NAG, 673 strains, 166 water samples from ponds and sewage and 674 fecal samples from patients with acute intestinal diseases have been studied; as a result, 54 phage races have been isolated. The occurrence of true lysogeny in V. cholerae NAG has been found to be infrequent (0.9-10% among newly isolated strains). Pseudolysogeny has been detected in 0.75% of the strains under study. Of the total number of truly lysogenic strains of V. cholerae NAG, 10% have been found to carry V. cholerae phages of types I, III, V, VII, IX. The possibility of the simultaneous existence of V. cholerae phages and V. cholerae NAG phages in the environment has been shown. Of the isolated phages, 45 races have no serological relationship with V. cholerae phages, while possessing specific lytic activity with respect to V. cholerae NAG.