Virulence of Endemic Nonpigmented Northern Australian Staphylococcus aureus Clone (Clonal Complex 75, S. argenteus) Is Not Augmented by Staphyloxanthin

• Published in: The Journal of infectious diseases 2013-08, Vol.208 (3), p.520-527
• Main Authors: TONG, Steven Y. C, SHARMA-KUINKEL, Batu K, HOLT, Deborah C, GIFFARD, Philip M, BAYER, Arnold S, DELEO, Frank R, FOWLER, Vance G, THADEN, Joshua T, WHITNEY, Adeline R, YANG, Soo-Jin, MISHRA, Nagendra N, RUDE, Thomas, LILLIEBRIDGE, Rachael A, SELIM, Maria A, SUN HEE AHN
• Format: Article
• Language: English
• Subjects: Animals; Australia; Bacteriology; Biological and medical sciences; Child; Disease Models, Animal; Fundamental and applied biological sciences. Psychology; Genetic Complementation Test; Humans; Infectious diseases; Major and Brief Reports; Male; Medical sciences; Mice; Mice, Inbred BALB C; Microbiology; Miscellaneous; Operon; Sepsis - microbiology; Sepsis - pathology; Staphylococcal Infections - microbiology; Staphylococcal Infections - pathology; Staphylococcal Skin Infections - microbiology; Staphylococcal Skin Infections - pathology; Staphylococcus aureus - genetics; Staphylococcus aureus - isolation & purification; Staphylococcus aureus - metabolism; Staphylococcus aureus - pathogenicity; Virulence; Virulence Factors - deficiency; Virulence Factors - genetics; Virulence Factors - metabolism; Xanthophylls - deficiency; Xanthophylls - genetics; Xanthophylls - metabolism
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1093/infdis/jit173

Staphylococcus aureus clonal complex 75 (herein referred to as S. argenteus) lacks the carotenoid pigment operon, crtOPQMN, responsible for production of the putative virulence factor, staphyloxanthin. Although a common cause of community-onset skin infections among Indigenous populations in northern Australia, this clone is infrequently isolated from hospital-based patients with either bacteremic or nonbacteremic infections. We hypothesized that S. argenteus would have attenuated virulence compared to other S. aureus strains due to its staphyloxanthin "deficiency." Compared to prototypical S. aureus strains, S. argenteus was more susceptible to oxidative stress and neutrophil killing in vitro and had reduced virulence in murine sepsis and skin infection models. Transformation with pTX-crtOPQMN resulted in staphyloxanthin expression and increased resistance to oxidative stress in vitro. However, neither resistance to neutrophil killing nor in vivo virulence was increased. Thus, reduced virulence of S. argenteus in these models is due to mechanisms unrelated to lack of staphyloxanthin production.