Innovative Methods of Combating Hospital-Acquired Infections
Given the prevalence of hospital-acquired infections (HAIs) in the United States, several companies are making efforts to develop technologies to reduce the occurrence of HAIs. In a multistate point-prevalence survey of health care-associated infections in published in 2014, it was estimated that there were about 648,000 patients with 721,800 health care-associated infections in U.S. acute care hospitals in 2011. The most common types of infections ranked with pneumonia being the most common and the most commonly reported pathogen to be Clostridium difficile.
Several companies have launched product lines to combat microbial growth and infection in hospitals, such as antimicrobial paint, curtains, and linens. At this time, the effect on reduction of bacteria and/or fungi is not clear since many of these products are new to the market. However, it will be interesting to see the long-term effects of these products as they become more prevalent.
One of the new developments to combat HAIs is Sherwin-Williams’ Microban® technology, aimed to provide antimicrobial protection through coating solutions. By engineering Microban® technology into the manufacturing workflow of coatings and product finishers, Sherwin-Williams is able to provide chemical coatings for powders, wood, plastics, electronics, medical equipment, and metal office furniture. Microban® technology is built into the molecular structure of the coating therefore it offers continuous protection by inhibiting growth of bacteria that typically cause stains and odors.
Sherwin Williams Paint Shield aims to provide antimicrobial protection through coating solutions.More recently, Sherwin-Williams has plans to launch their Paint Shield™ microbicidal paint line, offering 550 colors, this February. This is the first EPA-registered paint that actually kills bacteria after two hours of contact with the painted surfaced. Interestingly, Paint Shield™ tackles some of the more difficult to treat bacteria such as Staphylococcus aureus including MRSA, E.coli, Enterobacter aerogenes, and even VRE such as E.faecalis. EPA efficacy testing of this technology demonstrated that the effectivity of Paint Shield™ can actually last up to four years, provided the integrity of the surface to which it is applied is maintained during this time. Paint Shield™ reportedly kills greater than 99.9% of the organisms listed above and continues its microbicidal activity at 90% up to four years.
The active ingredient used in Paint Shield™ as disclosed by Sherwin-Williams is a quaternary ammonium compound called alkyl dimethyl benzyl ammonium chloride. The team of over 350 chemists at Sherwin-Williams’ Breen Technology Center in Cleveland have discovered a way to stabilize this compound within the paint without compromising the integrity of the paint or the integrity of the quaternary ammonium compound.
While this technology sounds cutting-edge, a lot of consumers and scientists are skeptical about the long-term benefits of Paint Shield™. Sherwin-Williams offers several technical documents on their website regarding their Paint Shield products. The Safety Data Sheet (SDS) for their Paint Shield™ products state that the product is considered hazardous by OSHA standards and is classified as a Category 2 substance for carcinogenicity. There are not many studies which provide information as to whether the risks outweigh the benefits for Paint Shield™ since this is a very new product but perhaps after a few years on the market, consumers and scientists alike will gain a better understanding of this technology.
Antimicrobial paint is not the only item on the market that was developed with the intention to reduce infections. Bio Technics Ltd in Scotland, developed their Endurocide™ line in 2005, offering the world’s first antimicrobial and sporicidal hospital curtains. With claims to have been tested against the hardiest of bugs such as C.difficile spores, MRSA, VRE, ESBL E.coli, and more, the curtains are made of 100% recyclable polypropylene and can be disposed of as hospital waste. The mechanism of action by which the curtains kill spores, bacteria, fungi, and H1N1 virus differs from that of antimicrobial paints.
Endurocide® antimicrobial and sporicidal disposable curtains are made of fabrics which have a biostatic polymer layer, meaning that when pathogens land on this fabric, they are trapped within the polymer and cannot replicate. The killing activity of the curtain begins once pathogens are trapped. The Endurocide® Sporicidal Curtain Liquid kills spores and bacteria, by causing damage to DNA and inhibiting cell production, respectively.
A similar type of technology is used in the development of antimicrobial linens. Research has shown that bed linen and similar sorts of fabrics and textiles have the ability to harbor bacteria such as S. aureus, P. aeruginosa, and E. faecium, but these bacteria survive standard washing processes. Thus, standard washing processes are often times inadequate in killing these opportunistic pathogens. Researchers based in the Polytechnical University of Catalunia in Barcelona, Spain have worked on developing a technology to make sanitary fabric aseptic, using zinc nanoparticles. The zinc nanoparticles, upon being immersed in water and tossed around in the vibrations of a washing machine, would “explode,” allowing them to become attached to the textile. Furthermore, the use of enzymes and biopolymers in addition to the zinc nanoparticles would allow the nanoparticles to more strongly adhere and resist degradation in high temperature laundry cycles.
However, some scientists doubt the efficacy of such a technology and have expressed concern about the implications for wide-spread resistance mechanisms. Just as bacteria gain resistance to antibiotics, they may evolve mechanisms to bypass the microbicidal activity of these antimicrobial textiles therefore the researchers who are developing this technology intend it to only be used in a hospital context.
While all these new technologies are ambitious in tackling the prevalence of HAIs, it may be a while before their efficacy is demonstrated. In the meantime, we can do our part to help reduce HAIs. The World Health Organization (WHO) suggests that hands are the most common vehicle for transmission and “hand hygiene” is the single most effective means of preventing HAIs because it reduces the risk of infection transmission between patients and personnel. In fact, hand hygiene has been evaluated in the context of reducing the transmission of multiple-drug resistance organisms (MDROs) such as MRSA, VRE, ESBL, and CRE. For example, one study showed that when hand hygiene compliance increased by 30%, there was a 24% reduction in the risk of acquiring a MRSA. Other studies have shown similar trends in which an increase in hand hygiene compliance has translated directly to reduced risk of acquiring MRSA and other infections by resistant E.coli and CRE like P. aeruginosa. It is interesting to see that something as simple as washing your hands can have a tremendous effect on one’s health and the health of others and it doesn’t require zinc nanoparticles or biostatic polymers!
Sources:
http://www.cdc.gov/hicpac/Disinfection_Sterilization/9_0PceticAcidHydroPoxide.html
http://www.nejm.org/doi/full/10.1056/NEJMoa1306801
https://www.sciencedaily.com/releases/2013/11/131118102424.htm
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3963198/
http://www.who.int/gpsc/5may/MDRO_literature-review.pdf
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Written by Nasim Delavari, February 2016
Nasim is a Technical Support Specialist and one of our Research and Development Microbiologists here at Hardy Diagnostics. She earned her Bachelors Degree in Microbiology from the California Polytechnic State University at San Luis Obispo.
