Abstract
The Classical Vibrio cholerae strain NIH 41 contains two temperate bacteriophages, designated VcA-1 and VcA-2, that are distinguished by immunity, plaque morphology, induction kinetics, and particle morphology. Both phage are serologically related to phage Kappa. However, only phage VcA-2 has the Kappa type host range and immunity. The induction kinetics and immunity patterns of Classical vibrios suggest that these strains may contain defective phage related to the phages isolated from NIH 41. Classical strain 569B releases phage-tail structures upon induction that are morphologically and serologically related to both phages VcA-1 and VcA-2. The possible reason for the defectiveness of these phages in 569B is discussed. It is concluded that complete or defective bacteriophages of the Kappa type morphology and serology are extremely prevalent in V. cholerae, regardless of biotype.