Regulation of the Propagation of HR Virus Plasmid

The carrier state of virus infected bacteria reported heretofore has been of the ‘curable’ (class I) type in which the host bacteria can be cured by growth in the presence of antiviral serum. Most of the progeny so obtained are sensitive to reinfection (Lwoff, 1953). The other type of carrier state (class II) can be found in animal viruses; the virus infection is noncurable and the virus-synthesizing capacity is transmitted to the daughter cells even when carrier cells divide in the presence of antiserum (Walker, 1964). There has been no report of a persistent infection of a DNA bacterial virus which resembles the class II of the carrier state of animal virus.