Characterization of a mouse-adapted Staphylococcus aureus strain

PLoS One. 2013 Sep 2;8(9):e71142. doi: 10.1371/journal.pone.0071142. eCollection 2013.

Abstract

More effective antibiotics and a protective vaccine are desperately needed to combat the 'superbug' Staphylococcus aureus. While in vivo pathogenicity studies routinely involve infection of mice with human S. aureus isolates, recent genetic studies have demonstrated that S. aureus lineages are largely host-specific. The use of such animal-adapted S. aureus strains may therefore be a promising approach for developing more clinically relevant animal infection models. We have isolated a mouse-adapted S. aureus strain (JSNZ) which caused a severe outbreak of preputial gland abscesses among male C57BL/6J mice. We aimed to extensively characterize this strain on a genomic level and determine its virulence potential in murine colonization and infection models. JSNZ belongs to the MLST type ST88, rare among human isolates, and lacks an hlb-converting phage encoding human-specific immune evasion factors. Naive mice were found to be more susceptible to nasal and gastrointestinal colonization with JSNZ than with the human-derived Newman strain. Furthermore, naïve mice required antibiotic pre-treatment to become colonized with Newman. In contrast, JSNZ was able to colonize mice in the absence of antibiotic treatment suggesting that this strain can compete with the natural flora for space and nutrients. In a renal abscess model, JSNZ caused more severe disease than Newman with greater weight loss and bacterial burden. In contrast to most other clinical isolates, JSNZ can also be readily genetically modified by phage transduction and electroporation. In conclusion, the mouse-adapted strain JSNZ may represent a valuable tool for studying aspects of mucosal colonization and for screening novel vaccines and therapies directed at preventing colonization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disease Models, Animal
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Multilocus Sequence Typing
  • Staphylococcal Infections / microbiology
  • Staphylococcus aureus / genetics
  • Staphylococcus aureus / pathogenicity*
  • Virulence / genetics
  • Virulence / physiology

Grant support

S.H. was supported by a Research fellowship (grant HO4345/1-1) from the German Research Foundation (http://www.dfg.de/en/) and S.W. by a Sir Charles Hercus Fellowship (09/099) from the Health Research Council of New Zealand (http://www.hrc.govt.nz/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.