Evaluation of Staphylococcus aureus virulence factors using a silkworm model

Shinya Miyazaki, Yasuhiko Matsumoto, Kazuhisa Sekimizu, Chikara Kaito

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

Previous studies have indicated that the silkworm model is useful for identifying virulence genes of Staphylococcus aureus, a human pathogenic bacterium. Here we examined the scope of S. aureus virulence factors that can be evaluated using the silkworm model. Gene-disrupted mutants of the agr locus, arlS gene and saeS gene, which regulate the expression of cell surface adhesins and hemolysins, exhibited attenuated virulence in silkworms. Mutants of the hla gene encoding α-hemolysin, the hlb gene encoding β-hemolysin, and the psmα and psmβ operons encoding cytolysins, however, showed virulence in silkworms indistinguishable from that of the parent strain. Thus, these S. aureus cytolysins are not required for virulence in silkworms. In contrast, the gene-disrupted mutants of clfB, fnbB and sdrC, which encode cell-wall-anchored proteins, attenuated S. aureus virulence in silkworms. In addition, the mutant of the srtA gene encoding sortase A, which anchors cell-wall proteins, showed attenuated virulence in silkworms. These findings suggest that the silkworm model can be used to evaluate S. aureus cell-wall proteins and regulatory proteins as virulence factors.

Original languageEnglish
Pages (from-to)116-124
Number of pages9
JournalFEMS Microbiology Letters
Volume326
Issue number2
DOIs
Publication statusPublished - Jan 1 2012
Externally publishedYes

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Keywords

  • Hemolysin
  • Regulatory factor
  • Silkworm model
  • Staphylococcus aureus
  • Virulence

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology
  • Genetics

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