| Abstrakt: |
STAPHYLOCOCCUS aureus can enter the bloodstream, leading to health complications such as sepsis, arthritis, endocarditis, and pneumonia. This study screened for the impact of six replication genes of cos phage 12 (φ12) on the evolution and transfer of cos S. aureus pathogenicity islands (SaPIbov5). An overnight culture of the S. aureus strain RN4220 diluted with fresh TSB was used in the bacteriophage φ12 titering assay. Phage-point mutagenesis was achieved using the pMAD vector, which facilitates homologous recombination in a two-step process. Finally, the transduction SaPI titering assays also utilized the S. aureus strain RN4220, which was then mixed with CaCl2 and fresh TSB. The study showed that ORF11, ORF12, and VirE mutants did not lyse or produce phage particles after titering into the recipient RN4220 strains. While ORF26, ORF10, and ORF04 mutants generated detectable plaques, the mutations may have an effect on phage replication or packaging after tittering. For instance, complemented φ12 ORF26, ORF10, and ORF04 mutant strains had fully restored phage titers. The experiment found that cos phages facilitate inter and intra-generically transfer of cosSaPIs. It was also established that φ12 transduces SaPIbov5. However, φ12 mutants in VirE, ORF12, and ORF11 did not show SaPI mobilization because of their effects on infective phage particles and lack of replication. The complemented φ12 VirE, ORF12, and ORF11 mutants had partly restored phage titers when they were expressed in the recipient and donor strains. Mutations in ORF26, 0RF10, and ORFO4 decrease the φ12's ability to transfer SaPIbov5. Generally, this study found a new mechanism that facilitates the transfer of SaPI and cos genes. While the VirE, ORF12, and ORF11 affect packaging and are necessary for replication and phage biology [ABSTRACT FROM AUTHOR] |
