IntroductionPreoperative marking is an essential safety practice to prevent "never" events, including wrong site surgery. Moreover, the Joint Commission regulations of the Universal Protocol require that patients be marked to indicate the operative site. Marking typically occurs with a pen or marker, which may be disposable or reusable. Previous studies have demonstrated that methicillin-resistantStaphylococcus aureus(MRSA) can survive in the dark, moist, capped environment of the marking pen and thus could plausibly be a nidus for transmission from patient to patient. The Joint Commission has established no increased risk of postoperative infection with these markings. With this study, we aimed to determine the colonization of surgical marking pens in the plastic surgery population.MethodsTwo marking pens from five different attending plastic surgeons at a single institution were cultured in standard fashion for aerobic and anaerobic growth. All pens were used repeatedly in office settings for performing patient markings. Those same ten marking pens were then used to mark incision sites on mock patients. Standard povidone-iodine prepping was then performed in a paint-only fashion over the skin markings, and cultures were again taken. A control group consisted of cultures from five sterile pens from the operating room. Each sterile pen was opened, uncapped, and then swabbed. All twenty-five cultures were analyzed in the hospital laboratory in a blinded fashion.ResultsThe five control pens revealed no bacterial growth. Of the 10 direct pen cultures, two samples grew coagulase-negative staphylococci and one culture containedPseudomonas aeruginosa. The 10-patient marked and prepped specimens showed eight negative cultures and two with coagulase-negative staphylococci. AlthoughPseudomonaswas detected on standard pen culture, no pseudomonal growth was present in any of the samples after patient marking and prepping with povidone-iodine.ConclusionsOur findings reaffirm that marking pens may be vehicles for bacterial transmission and expand upon previous studies by describing the presence of bacterial colonization on marking pens even after surgical site preparation with povidone-iodine.