Local Inflammation Exacerbates the Severity of Staphylococcus aureus Skin Infection

Department of Pediatrics, University of Chicago, Chicago, Illinois, United States of America.
PLoS ONE (Impact Factor: 3.23). 07/2013; 8(7):e69508. DOI: 10.1371/journal.pone.0069508
Source: PubMed

ABSTRACT

Staphylococcus aureus is the leading cause of skin infections. In a mouse model of S. aureus skin infection, we found that lesion size did not correlate with bacterial burden. Athymic nude mice had smaller skin lesions that contained lower levels of myeloperoxidase, IL-17A, and CXCL1, compared with wild type mice, although there was no difference in bacterial burden. T cell deficiency did not explain the difference in lesion size, because TCR βδ (-/-) mice did not have smaller lesions, and adoptive transfer of congenic T cells into athymic nude mice prior to infection did not alter lesion size. The differences observed were specific to the skin, because mortality in a pneumonia model was not different between wild type and athymic nude mice. Thus, the clinical severity of S. aureus skin infection is driven by the inflammatory response to the bacteria, rather than bacterial burden, in a T cell independent manner.

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Available from: Anita Chong, Jan 16, 2015
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    • "The demonstration that larger skin lesions also had increased numbers of bacteria recovered suggests a defect in bacterial clearance. Although the kinetics of bacterial clearance and the role of bacterial burden in the severity of dermonecrotic lesions remains to be fully elucidated[31,32], we and others have demonstrated that large differences in lesion severity (e.g., WT vs. µMT mice and strain 923 vs. ∆sbi or ∆sbi∆spa in this study) are accompanied by differences in bacterial burden and local inflammatory responses[25,333435. While the rapid kinetics suggested a role for nonspecific natural antibodies in defense against S. aureus SSTI, our findings that transfer of naïve BALB/c serum did not restore protection in µMT mice, whereas immune serum did, suggested instead for a role of elicited S. aureus-specific antibodies. "
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