Role of S. aureus virulence factors in promoting epidermal viral infectivity: Relevance for atopic dermatitis

Patients with atopic dermatitis (AD) are commonly colonized on their skin with Staphylococcus aureus (S. aureus).  The presence and abundance of S. aureus correlates with disease severity.  This information coupled with fact that AD patients experience recurrent and widespread cutaneous viral infections, lead us to hypothesize that S. aureus virulence factors may enhance epithelial viral infectivity and promote viral spread.  We are investigating the effects of different S. aureus strains and specific S. aureus virulence factors on primary human keratinocyte biology and epithelial vaccinia virus (VV) infection. Our findings suggest that S. aureus virulence factors, commonly observed in isolates of S. aureus from AD patients, greatly enhance the permissiveness of skin epithelial cells to VV infectivity and spread. This is likely a key contributor to AD subjects risk for eczema vaccinatum, a serious complication of VV infection.