Positive Bacterial Culture Results at a Dermatologic Surgery Center: A Single-Site Retrospective Review.

Abstract

Typical prophylactic coverage of suspected cutaneous surgical-site infections (SSIs) predominantly covers gram-positive bacteria. Data regarding the frequency of infection with unusual bacteria, not covered by prophylaxis, are not available. A retrospective 10-year review of culture-positive infections at a single academic site was performed. All positive bacterial culture results at the Washington University Center for Dermatologic and Cosmetic Surgery between October 31, 2007, and October 31, 2017, were collected and analyzed. Coagulase-negative staphylococcus accounted for 20.8% of positive culture results. Staphylococcus aureus caused 45.4% of infections. The remaining 33.8% were due to non-S. aureus bacteria, most frequently with Pseudomonas aeruginosa (10.8%). Numerous other gram-negative organisms and unusual gram-positive organisms were cultured. The lower extremity and ear were the only sites more likely to be infected with non-S. aureus bacteria. Smokers and immunosuppressed individuals were not more likely to have an SSI with non-S. aureus bacteria. A significant proportion of all SSIs with positive culture results was due to bacteria that are not sensitive to beta-lactam prophylaxis. Broader coverage for suspected SSI should be considered, particularly on the lower extremity and ear.