Staphylococcus bacteriophage tails with bactericidal properties: new findings.

The development of lytic bacteriophages as therapeutic products is an attractive alternative to antibiotics. In this study, we evaluated the potential of phage tails for lysing Gram-positive bacteria. Phage P954, a well-characterized temperate staphylococcal phage, was found to adsorb to a large number of Staphylococcus aureus clinical isolates, although it lyses only 24% of the tested isolates. However, P954 phage tails generated by interruption of phage assembly were bactericidal against all the phage-resistant isolates. Phage tail preparations were trypsin sensitive with an apparent molecular weight of over 300 kDa. PCR analysis of the P954 phage-resistant isolates indicated the integration of P954-like prophages into the host genomes. Our study demonstrates for the first time that P954 bacteriophage tails have a much broader host range than the intact phage because phage tails are not affected by superinfection immunity or vulnerable to host restriction endonucleases.