A Morphologic Study of Mycobacteria Infected with D32 Phage1,2

Abstract

Significant numbers of a D32 phage-infected mycobacterial population show no changes for 50 minutes after infection, as revealed by ultrathin sections in the electron microscope. At approximately [dagger] This symbol [dagger] before abstract number indicates an abstract edited by the editor(s) of the source journal, and republished unaltered by BA editorial staff. 70 minutes after infection, electron-dense bodies of about the same diameter as D32 phage heads become visible in the infected cells. These particles are not found in uninfected cells and their numbers increase with time in the infected population. An intact nuclear structure was not found in cells which contained virus-like particles. Sections of mature phage indicate that the combination of nucleic acid with a protein coat is not very firm. These observations of phage-infected myco-bacteria are essentially similar to those found in Escherichia coli coliphage studies by other investigators.