Staphylococcus aureus survival in human blood

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is abundant in hospitals and in the United States is a leading cause of mortality due to infectious agents. Community-associated MRSA (CA-MRSA) strains such as USA300, which typically cause disease outside of healthcare settings, are also prevalent in the United States. Although most CA-MRSA infections affect skin and soft tissue, the pathogen can enter the bloodstream and ultimately cause severe disease. In a recent paper, we used USA300-specific microarrays to generate a comprehensive view of the molecules that facilitate S. aureus immune evasion and survival in human blood. Notably, genes encoding proteins involved in iron-uptake and utilization and gamma-hemolysin (hlgABC) are highly up-regulated by USA300 during culture in human blood. Here we discuss the potential implication of these findings and the possible role of gamma-hemolysin in the success of S. aureus as a human pathogen.

Acknowledgments

The authors are supported by the Intramural Research Program of the National Institute of Allergy and Infectious Diseases, National Institutes of Health. We thank Scott D. Kobayashi, Ph.D. (NIAID) for critical review of the manuscript.

Figures and Tables

Figure 1 S. aureus in human blood. (A) Hypothetical model of the potential contribution of Hlg to survival of S. aureus in human blood (See text for details). (B) interaction of strain USA300 with human neutrophils in heparinized human blood.

Original Article: Malachowa N, Whitney AR, Kobayashi SD, Sturdevant DE, Kennedy AD, Braughton KR, et al. Global changes in Staphylococcus aureus gene expression in human blood. PLoS ONE 2011; 6:18617; PMID: 21525981; http://dx.doi.org/10.1371/journal.pone.0018617

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