Staphylococcus aureus prophage-encoded protein causes abortive infection and provides population immunity against kayviruses

The aim of the study was to investigate the resistance mechanism of Staphylococcus aureus towards lytic phages of the genus Kayvirus and the role of the membrane-anchored protein (primary accession Q2FYE0) designated PdpSau encoded by Staphylococcus aureus prophages. PdpSau does not prevent the infecting kayvirus from adsorbing onto the host cell and delivering its genome into the cell, but phage DNA replication is halted. Changes in the cell membrane polarity and permeability were observed 10 min after the infection leading to prophage-activated cell death. The LC-MS/MS analysis, as one of the methods, was used for protein detection and to find out whether this protein is predominantly presented in membranes. These findings are relevant for the advancement of phage therapy.