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

## TL;DR

This paper introduces a mouse-adapted Staphylococcus aureus strain, JSNZ, as a model for infection studies with detailed genomic and proteomic data.

## Contribution

The study provides a comprehensive genomic and proteomic characterization of the mouse-adapted S. aureus strain JSNZ.

## Key findings

- JSNZ has a deletion in the hsdR gene, explaining its high transformability.
- JSNZ proteome is similar to common S. aureus reference strains under lab conditions.
- JSNZ secretes a novel serine protease Jep at high levels in stationary phase.

## Abstract

•Establishing the mouse-a S. aureus strain JSNZ as a reference strain for mouse infection studies.•Providing publicly available comprehensive genomic and proteomic characterisation.•Deletion in the restriction subunit hsdR explains the high transformability of JSNZ.•JSNZ proteome mirrors that of common reference strains under laboratory conditions.•JSNZ secretes a novel serine protease Jep at remarkably high levels.

Establishing the mouse-a S. aureus strain JSNZ as a reference strain for mouse infection studies.

Providing publicly available comprehensive genomic and proteomic characterisation.

Deletion in the restriction subunit hsdR explains the high transformability of JSNZ.

JSNZ proteome mirrors that of common reference strains under laboratory conditions.

JSNZ secretes a novel serine protease Jep at remarkably high levels.

Mouse-adapted Staphylococcus aureus strains have become increasingly relevant in infection research thanks to their ability to better recapitulate clinical infection dynamics in mouse models. However, detailed characterisations required to establish a corresponding reference strain are still lacking. The mouse-adapted CC88 strain JSNZ appears to be an ideal candidate for a reference strain. Here, we present a comprehensive genomic and proteomic characterisation of JSNZ. Whole genome sequencing was performed using a combination of short and long reads. Proteomic profiling was conducted under standard laboratory conditions in TSB and RPMI during exponential and stationary growth using LC-MS/MS. The updated, closed genome sequence of JSNZ was integrated into AureoWiki for user-friendly access and direct comparison to long-established reference strains. Genome architecture and orthologues genes were compared between JSNZ and further strains contained in AureoWiki. Genome data revealed a deletion in the restriction endonuclease gene hsdR, likely explaining the previously reported efficient transformation. This positions JSNZ as a hub for genetic modification of other CC88 isolates. 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 standardised resource to enhance experimental reproducibility and cross-study consistency in the field.

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