Surface Micropattern Resists Bacterial Contamination Transferred by Healthcare Practitioners

Abstract

Environmental contamination contributes to an estimated 20-40% of all hospital- acquired infections (HAI). Infection control practices continue to improve, but multipronged approaches are necessary to fully combat the diversity of nosocomial pathogens and emerging multidrug resistant organisms. The Sharklet™ micropattern, inspired from the microtopography of shark skin, was recently shown to significantly reduce surface contamination but has not been evaluated in a clinical setting. The focus of this study was the transfer of bacteria onto micropatterned surfaces compared to unpatterned surfaces in a clinical simulation environment involving healthcare practitioners. Physician volunteers were recruited to participate in an emergency medicine scenario involving a contact-precaution patient with an acute pulmonary embolism. Prior to scenario initiation, Staphylococcus aureus was inoculated onto the leg of a simulation mannequin and fresh micropatterned and unpatterned surface films were placed on a code cart, cardiac defibrillator shock button, and epinephrine medication vial. Six physicians interacted with micropatterned surfaces and five physicians interacted with unpatterned surfaces in separate scenarios. Bacterial load loss from the first contact location (control film over the femoral pulse) to subsequent unpatterned or micropatterned surface test locations was quantified as a log reduction (LR) for each surface type. The code cart, cardiac defibrillator button, and medication vial locations with micropatterned surfaces resulted in LRs that were larger than the unpatterned LRs by 0.64 (p=0.146), 1.14 (p=0.023), and 0.58 (p=0.083) respectively for each location. The geometric mean CFU/RODAC at the first control surface touched at the femoral pulse pads ranged from 175-250 CFU/RODAC (95% confidence interval). Thus, the micropatterned LRs were consistently greater than the unpatterned LRs, substantiating the micropattern-dependent reduction of microorganism transfer. Principal component analysis showed that the LRs for the code cart and the cardiac defibrillator button highly covaried. Thus, a single mean LR was calculated from these two locations for each surface type; 5.4 times more bacteria attached to the unpatterned surfaces compared to the micropatterned surfaces (p = 0.058). The simulated clinical scenario involving healthcare practitioners demonstrated that the micropatterned surface reduced the transfer of bacterial contamination based on the larger LRs for the micropatterned surface compared to control surfaces. Further investigation in hospital rooms where patients are receiving care will ultimately reveal the capability of micropatterned surfaces to minimize the incidence of HAIs.