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Title: Comparison of livestock-associated and community-associated Staphylococcus aureus pathogenicity in a mouse model of skin and soft tissue infection

Industrial hog operation (IHO) workers are at increased risk of carryingStaphylococcus aureusin their nares, particularly strains that are livestock-associated (LA) and multidrug-resistant. The pathogenicity of LA-S. aureusstrains remains unclear, with some prior studies suggesting reduced transmission and virulence in humans compared to community-associated methicillin-resistant (CA-MRSA)S. aureus. The objective of this study was to determine the degree to which LA-S. aureusstrains contracted by IHO workers cause disease relative to a representative CA-MRSA strain in a mouse model of skin and soft tissue infection (SSTI). Mice infected with CC398 LA-S. aureusstrains (IHW398-1 and IHW398-2) developed larger lesion sizes with higher bacterial burden than mice infected with CA-MRSA (SF8300) (p < 0.05). The greatest lesion size and bacterial burden was seen with a CC398 strain that produced a recurrent SSTI in an IHO worker. The LA-S. aureusinfected mice had decreased IL-1β protein levels compared with CA-MRSA-infected mice (p < 0.05), suggesting a suboptimal host response to LA-S. aureusSSTIs. WGSA revealed heterogeneity in virulence factor and antimicrobial resistance genes carried by LA-S. aureusand CA-MRSA strains. The observed pathogenicity suggest that more attention should be placed on preventing the spread of LA-S. aureusinto human populations.

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Publication Date:
Journal Name:
Scientific Reports
Nature Publishing Group
Sponsoring Org:
National Science Foundation
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