Surface micropattern resists bacterial contamination transferred by healthcare practitioners

Abstract

Environmental contamination contributes to an estimated 20-40% of all hospitalacquiredinfections (HAI). Infection control practices continue to improve, butmultipronged approaches are necessary to fully combat the diversity of nosocomialpathogens and emerging multidrug resistant organisms. The Sharkletâ„¢ micropattern,inspired from the microtopography of shark skin, was recently shown to significantlyreduce surface contamination but has not been evaluated in a clinical setting. Thefocus of this study was the transfer of bacteria onto micropatterned surfaces comparedto unpatterned surfaces in a clinical simulation environment involving healthcarepractitioners. Physician volunteers were recruited to participate in an emergencymedicine scenario involving a contact-precaution patient with an acute pulmonaryembolism. Prior to scenario initiation, Staphylococcus aureus was inoculated onto theleg of a simulation mannequin and fresh micropatterned and unpatterned surfacefilms were placed on a code cart, cardiac defibrillator shock button, and epinephrinemedication vial. Six physicians interacted with micropatterned surfaces and fivephysicians interacted with unpatterned surfaces in separate scenarios. Bacterial loadloss from the first contact location (control film over the femoral pulse) to subsequentunpatterned 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 withmicropatterned surfaces resulted in LRs that were larger than the unpatternedLRs by 0.64 (p=0.146), 1.14 (p=0.023), and 0.58 (p=0.083) respectively for eachlocation. The geometric mean CFU/RODAC at the first control surface touched at thefemoral 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 cardiacdefibrillator button highly covaried. Thus, a single mean LR was calculated fromthese two locations for each surface type; 5.4 times more bacteria attached to theunpatterned surfaces compared to the micropatterned surfaces (p = 0.058). Thesimulated clinical scenario involving healthcare practitioners demonstrated that themicropatterned surface reduced the transfer of bacterial contamination based onthe larger LRs for the micropatterned surface compared to control surfaces. Furtherinvestigation in hospital rooms where patients are receiving care will ultimately revealthe capability of micropatterned surfaces to minimize the incidence of HAIs.