Integrated genomic and proteomic analysis of the mouse-adapted Staphylococcus aureus strain JSNZ

Mouse-adapted Staphylococcus aureus strains have become increasingly relevant for infection research due to their ability to better recapitulate clinical infection dynamics in mouse models. However, detailed characterizations to establish an applicable reference strain remains limited. The mouse-adapted CC88 strain JSNZ appears to be an ideal candidate for a reference strain, because CC88 is widely spread among laboratory mice and frequently employed in mouse colonization and infection models. Moreover, JSNZ demonstrates high genetic transformability comparable to that of commonly used laboratory strains. In this study, we present a comprehensive genomic and proteomic characterization of JSNZ. Proteomic profiling was conducted under standard laboratory conditions in TSB and RPMI during exponential and stationary growth using LC-MS/MS. Proteomic profiling of JSNZ indicated broad similarity to common S. aureus reference strains. However, a striking exception was the novel serine protease Jep, which constituted approximately 75% of the exoproteome in stationary TSB cultures. Overall, these findings affirm JSNZ as a robust and genetically tractable model strain for murine S. aureus infection research and contribute a valuable standardized resource to enhance experimental reproducibility and cross-study consistency in the field.