869. Do serum antibodies to Staphylococcus aureus PSMα3 protect against skin and soft-tissue infection? Evidence from a case-control study among military trainees at high risk for disease
Session: Poster Abstract Session: Bacterial Infections: Pathogenesis and Immunity
Friday, October 9, 2015
Room: Poster Hall
Background: Soldiers undergoing military training are at high risk for staphylococcal skin and soft-tissue infections (SSTI), especially those caused by methicillin-resistant S. aureus (MRSA). Immune correlates of protection against these infections are undefined. We determined whether high concentrations of serum IgG against S. aureus virulence factors conferred protection against purulent S. aureus SSTI.

Methods: We conducted a case-control study in US Army trainees from August 2011 through January 2012. Trainees presenting for care of SSTI (cases) or non-infectious conditions (controls) were prospectively enrolled. Participants’ nares were swabbed to evaluate S. aureus colonization status at enrollment. Serum drawn prior to the start of training was obtained for participants and subjected to a multiplex bead-based flow suspension array to measure levels of serum IgG to 14 S. aureus antigens. Antibody levels were compared between those who did versus did not develop subsequent SSTI. 

Results: We enrolled 142 cases and 544 controls. Of the cases, 77 (54%) were MRSA SSTI. Of the 121 (85.2%) S. aureus isolates that were typed, 96 (79%) were USA300. In univariate analysis, increasing titers of anti-PSMα3 antibody were associated with reduced odds of USA300 SSTI (OR=0.58, 95% CI: 0.38-0.87). In multivariate analysis, increasing titers of anti-PSMα3 antibody were associated with reduced odds of MRSA SSTI (OR=0.39, 95% CI: 0.21-0.73). 

Conclusion: Military trainees with high concentrations of anti-PSMα3 serum antibody were less likely to develop MRSA-associated skin and soft-tissue infection during training. Further investigation is needed to evaluate the immunogenicity of PSMα3 for the prevention of SSTI.

Eugene Millar, PhD1, Carey Schlett, MPH2, Tianyuan Cui, MA3, David Tribble, MD, DrPH, FIDSA4, Eric Hall, PhD5, Jeffrey Lanier, MD6, Lauren Nagy, PhD7, Michael Ellis, MD, FIDSA8, Hwang-Soo Joo, PhD9, Chih-Lung Fu, PhD9, Michael Otto, PhD, FSHEA; National Institute of Allergy and Infectious Diseases/National Institutes of Health10 and Danett Bishop, Ph.D.7, (1)Infectious Disease Clinical Research Program, Rockville, MD, (2)Inf Dis Clin Res Prg, Uniform Serv Univ, Bethesda, MD, (3)Infectious Disease Clinical Research Program, Uniformed Services University, Rockville, MD, (4)Infectious Disease Clinical Research Program, Uniformed Services University of the Health Sciences, Bethesda, MD, (5)Navy Medical Research Center, Silver Spring, MD, (6)Martin Army Community Hospital, Fort Benning, GA, (7)Wound Infections Department, Naval Medical Research Center, Silver Spring, MD, (8)Department of Medicine, Uniformed Services University, Bethesda, MD, (9)National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, MD, (10)National Institute of Allergy and Infectious Diseases/National Institute of Health, Hamilton, MT

Disclosures:

E. Millar, None

C. Schlett, None

T. Cui, None

D. Tribble, None

E. Hall, None

J. Lanier, None

L. Nagy, None

M. Ellis, None

H. S. Joo, None

C. L. Fu, None

M. Otto, None

D. Bishop, None

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