Characterisation of a Helicobacter pylori phage (HP1)

Summary. The infection of two Helicobacter pylori strains with a phage-containing supernate of the lysogenic H. pylori strain IMMi 290/89 resulted in a lytic cycle and propagation of phage HP1. In negatively-stained preparations, the empty phage heads measured 55–60 nm in diameter and mature heads measured 50 nm. The flexible, striated phage tail was c. 170 nm in length and 9·5 nm in diameter. The phage showed a mean density of 1·40 g/cm3 in sucrose-density gradients and contained double-stranded DNA c. 22000 bp in length.