While it may not be a silver bullet for eradicating germs that live on surfaces, a new coating that contains silver nanoparticles does appear to reduce the number of germs that survive on surfaces, according to a study conducted by researchers at the University of Iowa Hospitals and Clinics.
The findings suggest that the coating, which is known as NG3982 and is manufactured by Deck2Walls, may be potentially useful for preventing infections in hospital settings.
"The results of our study suggest that this coating can decrease the number of germs—particularly Staph bacteria—contaminating surfaces in hospital rooms," says Dr. Loreen Herwaldt, UI professor of internal medicine and director of hospital epidemiology at UI Hospitals and Clinics. "This finding is important because environmental surfaces may be a source of infectious agents for hospitalized patients, and products that limit surface contamination might be a useful measure for preventing infections."
Herwaldt presented the study findings on Sept. 8 at ICAAC 2014, the 54th International Conference on Antimicrobial Agents and Chemotherapy, in Washington D.C.
The UI study team coated four high-touch surfaces (bedside table, nurse call button, chair, and overbed table) in five patient rooms on a solid organ transplant unit with the silver-based surface coating. The same high-touch surfaces in five more rooms were not coated and served as control surfaces. The researchers analyzed the number and type of germs (bacteria and fungi) contaminating each surface on a weekly basis over a period of 16 weeks.
Overall, they found that the number of germs was lower on coated surfaces (an average of 250 colony forming units) compared with uncoated surfaces (average of 290). In particular, the number of germs obtained from bedside tables and nurse call buttons were 44 percent and 38 percent lower on coated areas, differences that were close to the level considered to be significant.
Analyzing the data for all germs that cause infections, the team did not find significant differences in the percent of surfaces contaminated with germs between the coated and uncoated surfaces—these germs were found on 27 percent of coated surfaces and 31 percent of uncoated surfaces. However, for one particular type of bacteria—Staphyloccocus aureus, or "Staph" —the coating did make a significant difference.
Staph bacteria can cause very serious infections in hospitalized patients and the number of antibiotics available to treat methicillin-resistant Staph (or MRSA) infections is limited.
The study showed that Staph bacteria—both methicillin-susceptible Staph and methicillin-resistant Staph (MRSA)—were found significantly less frequently on coated surfaces than on uncoated surfaces (S. aureus 15 percent vs. 31 percent; MRSA 1 percent vs. 22 percent).
"These preliminary findings suggest that further studies are warranted to assess whether this coating could be an effective infection prevention measure," Herwaldt says.
In addition to Herwaldt, the UI research team included Hsiu-Yin Chiang, Linda Boyken, Sandra Cobb, Bradley Ford, Rachel Miller, Sam Miner, Alan Reed, Shailesh Tendolkar, and Dan Diekema.
(Note to Editors: This release was adapted from a news release prepared by ICAAC media relations staff.)