1167. Venous Thrombosis in Children with Staphylococcus aureus Musculoskeletal Infection is Not Associated with Increased Expression of Genes Involved in Adhesion and Coagulation
Session: Poster Abstract Session: Staphylococcus aureus Infections in Children
Saturday, October 22, 2011
Room: Poster Hall B1
Background: The mechanism underlying the increased incidence of venous thrombosis (VT) associated with Staphylococcus aureus (SA) musculoskeletal infections in children is unstudied. Increased prevalence of SA expressing virulence factors implicated in adhesion and coagulation may explain this phenomenon. 

Methods: We evaluated thirteen SA isolates from children with musculoskeletal infections associated with VT and thirteen isolates from children without VT (matched by gender, age, type and site of infection) for the presence of genes involved in adhesion and coagulation: collagen adhesin, staphylococcal accessory regulator T, fibronectin-binding proteins A and B, clumping factors A and B, serine-aspartate repeat proteins C, D and E, and extracellular adherence protein. We assessed coagulase production and the expression levels of the accessory gene regulator (agr) as an indicator of overall gene expression patterns. Patient records were reviewed for clinical characteristics associated with the development of VT. 

Results: In each group 5 isolates were methicillin-sensitive (MSSA) and 8 were methicillin-resistant (MRSA).  All MRSA strains were SCCmec type IVa.  All isolates were Panton-Valentin leukocidin positive. Genes involved in adhesion and coagulation were present equally in both groups, and no significant differences were observed in coagulase production or the expression level of agr.  CRP and ESR at admission, BMI % for age, and the length of symptoms prior to admission were not significantly different in patients that developed VT and those that did not.  Length of hospitalization was not significantly different between the two study groups.

Conclusion: There is no association between the presence and expression of genes involved in adhesion and coagulation and venous thrombosis in children with Staphylococcus aureus musculoskeletal infections. As yet unrecognized host and/or SA virulence factors likely play the key role in development of VT.

Subject Category: P. Pediatric and perinatal infections

Nada Harik, MD1, Janet Hume, MD, PhD2, Tenita McCoy1, Lindsay Evans1 and Mark Smeltzer, PhD1, (1)University of Arkansas for Medical Sciences, Little Rock, AR, (2)Pediatric Critical Care, University of Texas Southwestern Medical Center, Dallas, TX


N. Harik, None

J. Hume, None

T. McCoy, None

L. Evans, None

M. Smeltzer, None

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