Close the Door on Microbes

When you open a door, you’re probably not thinking about anything more than entering another room. But on a microscopic level you’re giving a virtual handshake to every person who has recently touched that doorknob or handle. When you grab that door handle, potential disease-causing bacteria may grab on to you and come along for the ride.1

More than just sounding disgusting, bacteria on door handles can be a serious problem in offices, malls and other public areas, not to mention in healthcare environments, where 75,000 people die each year from hospital-acquired infections.

Bacteria like Escherchia coli and Staphylococcus aureus can transmit severe illness if doorknobs aren’t cleaned and disinfected regularly. And “regularly” is probably more often than you would expect: Researchers have found that antibiotic-resistant bacteria, including Methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycin-resistant Enterococcus (VRE), rebound above established safe levels only two hours after a surface is disinfected.3

No one has the time to clean doorknobs every two hours, plus disinfectants can contain harsh chemicals like bleach and peroxide, which may cause respiratory irritation, be harmful if swallowed, injure bare skin, and damage or discolor the objects they’re trying to treat.

Fortunately, nature has given us help to control the spread of bacteria in our environment. Silver has been used for centuries as an antimicrobial; the ancient Greeks, Romans, Phoenicians and Macedonians used silver either to preserve food and water or to heal wounds and incisions. Unlike many disinfectant chemicals, small amounts of silver don’t kill bacteria instantly on contact, rather they disrupt bacteria’s metabolism and prevent reproduction, which ultimately kills off bacteria colonies.4,5,6

Frequent hand-washing and disinfecting of surfaces are essential steps to avoiding any potential illnesses transmitted by bacteria on doorknobs and handles, of course. But silver antimicrobials can make those practices even more effective by making surfaces of common bacteria transmitters, like doorknobs, inhospitable for bacteria to survive.


  1. Wojgani H, Kehsa C, Cloutman-Green E, Gray C, Gant V, et al. Hospital door handle design and their contamination with bacteria: A real life observational study. Are we pulling against closed doors? PLoS ONE, 2012; 7(10): e40171. doi:10.1371/journal.pone.0040171
  2. Attaway, Hubert H. et al. Intrinsic bacterial burden associated with intensive care unit hospital beds: Effects of disinfection on population recovery and mitigation of potential infection risk. American Journal of Infection Control, 2013; 40(10), 907-912.
  3. Rosenkranz, H.S. & Carr, H.S. Silver sulfadiazine: Effect on the growth and metabolism of bacteria. Antimicrob Agents Chemother, 1972; 2(5):367-372 (and references cited therein).
  4. Jung, W. K., Koo, H. C., Kim, K. W., Shin, S., Kim, S. H., & Park, Y. H. Antibacterial activity and mechanism of action of the silver ion in Staphylococcus aureus and Escherichia coli. Applied and Environmental Microbiology, 2008; 74(7), 2171-2178.
  5. Morones-Ramirez, J., Winkler, J. A., Spina, C. S. & Collins, J.J. Silver Enhances Antibiotic Activity Against Gram-Negative Bacteria. Science Translational Medicine, 2013; 5(190), 190ra81.