Kismat Touhid, Grade 10, ISEC 2015 Runner-Up

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As the world continues to modernize and reach new plateaus of technological and engineering successes, our urban areas are developing. More and more people are being packed into the densely populated cities that are popping up over both already developed and still-developing countries. With the rise of antibiotic-resistant bacteria and increases in contact with strangers met on the streets and in metro stations, the state of hygiene of a single individual is now more than ever having a direct impact on the collective well-being of a community. Discovering cheap and effective ways of constraining the transfer of infections, whether the mediums they travel be through physical contact, water, air, etc. is becoming important in our ever-growing society. A relatively recent innovation, the utilization of the already valuable metal of copper to inhibit the growth of harmful microorganisms, is already observable in our public institutions, mainly our hospitals.

Health-care associated infections (HCAI) are infections patients and/or medical caretakers acquire during their stay at a medical treatment facility. The ironic reality is that millions of patients and healthcare workers (to a lesser degree) around the world are in some way influenced by HCAI. According to the World Health Organization (WHO), “HCAI results in prolonged hospital stays, long-term disability, increased resistance of microorganisms to antimicrobials, massive additional costs for health systems, high costs for patients and their family, and unnecessary deaths” (13). Multiple studies have been done outlining the legitimacy of the HCAI problem. An article published by the New England Journal of Medicine in 2014 states, “…4.0% of inpatients in U.S. acute care hospitals had at least 1 health care–associated infection, yielding an estimate of 648,000 inpatients with a total of approximately 721,800 such infections in 2011” (4). Another 2011 WHO report titled Report on the Burden of Endemic Health Care–Associated Infection described data collected by the European Center for Disease Prevention and Control concerning this issue, stating that 4,131,000 patients are affected every year by HCAI (12). Again, the validity of this problem cannot be stressed enough. Once this is understood, we may be able to proceed in discussing various ways of combating harmful bacteria originating from places traditionally thought to have been used in the battle against disease in the first place.

As mentioned above, it has been discovered that copper harbors unique properties that help it undermine the bodily structures of microorganisms, much like alcohol or extremely high temperatures do. “Antimicrobial copper”, as it’s called, works by punching holes into the cell membranes of any creepy-crawlies that reside on its surface. Copper, like most other metals, have relatively low electronegativities, meaning that the element’s atoms have a tendency to give up its electrons to elements belonging towards the right side of the periodic table. This is why metals are considered good conductors in the first place – the nuclei of copper atoms don’t seem to tug on its electrons very strongly, rendering its electrons very mobile and very susceptible to outside influence (magnetic fields for example). In any bacterium, there exists a phenomenon dubbed transmembrane potential: the difference in electrical potential outside and inside the membrane lining of a cell (11). This is very important to note, as transmembrane potential is a fundamental function of any microorganisms in the transfer of essential ions (such as sodium or potassium) from within the cell to its surroundings. When tampered with, the results may turn out to be devastating for the organism’s chances at survival. Contact between a bacterium and a sheet of copper “short circuits” the current already going into the cell (5), weakening the membrane and leaving it exposed to copper ions that begin flooding its innards. The cell is rendered obsolete in a matter of seconds, as the copper ions chemically bond to its enzymes, making them useless. At this point in time, the cell can no longer repair its membrane nor produce the energy it needs to keep thriving.

Surprisingly, this was a phenomenon used to the advantage of many well-known civilizations of the past, thousands of years ago. Copper was used by the ancient Greeks and Egyptians to transport water, as they’d noticed no fungi growing when water was stored in vessels constructed of this type of material (1). Copper containers in ancient Persia had been used “for water disinfection and food preservation…” (3) – even other metals that demonstrated similar properties, such as silver, were used in the preservation of wine, milk, vinegar, etc. Often times the point of discussion should focus less on how a concept was realized, but how that concept may be applied. So here we are in the twenty-first century, still attempting to make the most out of the environment we inhabit, still trying to conjure up new ways of engineering a well-studied material to best suit our interests at the time.

But why are new methods of bacterial infection prevention even pursued? Don’t effective ways of treating illnesses cause by these pathogens already exist, say, in the form of antibiotics? As mentioned earlier, antibiotic-resistant bacteria, known colloquially as “super bugs”, are gaining prominence. With the discovery of penicillin in the 1920’s and several additional kinds of antibiotics later on, humanity had made a huge leap forward in the medical field (2). What wasn’t foreseen, or emphasized, at the time however, was that continued use of these drugs would force selective pressures on our persevering single-celled organisms. Those of which that underwent favorable mutations began to survive antibiotics on therapeutic levels – they evolved to work their way around our defenses. Today, germs such as carbapenem-resistant Enterobacteriaceae (CRE) and multi-drug-resistant Mycobacterium tuberculosis (MDR-TB) are becoming tolerant of even the strongest of antibiotics, leaving a rapidly growing public health concern (6,10). If left unchecked, it could mean disaster for the collective well-being of the human populace of the near-future. Fortunately, efforts are being made in order to promote social awareness, reduce prescriptions of antibiotics unless they are absolutely necessary, and to determine more unique yet efficacious procedures in regulating the rise of super bugs. Employing copper and its alloys (which may include brass or bronze) in tests performed to see how they react has yielded remarkably positive results, as antimicrobial copper is “registered with the US Environmental Protection Agency (EPA) as being able to kill greater than 99.9% of infection causing bacteria* within two hours of exposure” (6)!

Thusly, hospitals have recently been pushing to add copper installments to their facilities – things such as bed rails, cabinets, electronic door access buttons, etc. are being switched out for their copper equivalents. The effects of these changes are being closely monitored, as they should be. A recent journal article published by the Cambridge University Press described an experiment done where the researchers sought to determine whether replacing hospital objects with copper coated ones in the intensive care unit produced any significant difference in the rate at which patients acquired an HCAI. The data collected seems to suggest that copper alloy-surface objects really do display the biocidal properties that are being discussed. “For [HCAI] only, the rate was reduced from [8.1%] to [3.4%]” (7). This definitely conveyed a substantial decrease in the prevalence of hospital-acquired infection. Being as it is however, it’s preferable to have more experiments and research done to better gauge the effectiveness of copper in mitigating the spread of HCAI, as this is still a fairly new development.

In fact, one of the reasons this isn’t something that’s widely discussed is because it’s still a new development. An article from http://healthtrustpg.com/ quotes Julia Moody, the director of infection prevention and clinical services at HCA (Hospital Corporation of America), saying:

One published study associates copper coatings on specific high-touch surfaces with a reduced rate of hospital-acquired infections, but the contribution of copper technology to a direct reduction in HAIs is unresolved and requires additional study.

Antimicrobial copper is also expensive in that it requires at least 58 percent of its alloy to consist of copper metal (5) – investors just don’t have enough information to trust that there will be a consistent, long term profit out of funding projects related to this.

That’s not to say that health care-associated infections are not of any significance to our economy – the CDC’s report from 2009 actually stated, “the overall annual direct medical costs of HAI to U.S. hospitals ranges from $28.4 to $33.8 billion” (8)! If copper-coating medical/hospital equipment turns out to be an effective way of reducing the rate of these infections, not only will it substantially better the state of our public hygiene, but it would save hospitals a ton of money in the long run, as well as patients who are forced to stay in hospitals longer than was initially intended because of any accidental contact with an HCAI. In 3rd world countries, this would be especially crucial in preventing unnecessary casualties from diseases that would otherwise be untreatable. The uses of antimicrobial copper don’t have to be limited to hospitals – public services such as city buses/trains are also potential subjects of benefit, as well as cooking surfaces at home. Again, it’s too early to make any definitive assumptions. It’s precisely this element of unascertained potential imbued in this recent scientific development that makes it an intriguing one to follow. The means of enhancing the state of humanity continue to grow endlessly as more and more researchers flock to investigate the latent possibilities of using a material mankind has known for quite a large portion of its modern history!

 

References/Works Cited

  1. Erica, M. (2014, November 12). Just how does copper kill germs?. Retrieved October 2, 2015, from http://blog.eoscu.com/blog/just-how-does-copper-kill-germs
  2. Genetic Science Learning Center (2014, June 22) What Is An Antibiotic?. Learn.Genetics. Retrieved October 05, 2015, from      http://learn.genetics.utah.edu/content/microbiome/antibiotics/
  3. Lemire, J., Harison, J., & Turner, R. (2013). Antimicrobial activity of metals: mechanisms, molecular targets and applications. Nature Reviews Microbiology, (11), 371-384.
  4. Magill, S. S., Edwards, J. R., Stat, M., Bamberg, W., Beldavs, Z., Dumyati, G., . . . Kainer, M. (2014). Multistate Point-Prevalence Survey of Health Care–Associated    The New England Journal of Medicine. Retrieved from www.nejm.org/doi/full/10.1056/NEJMoa1306801#t=articleResults
  5. Michels, Noyce, & Keevil. (2009). The Science behind Antimicrobial Copper. Retrieved from http://antimicrobialcopper.com/us/scientific-proof/how-it-works.aspx
  6. PR Newswire. (2013, March 12). Copper Kills Antibiotic-Resistant ‘Nightmare Bacteria’ — NEW YORK, March 12, 2013 /PRNewswire/ –. Retrieved from      http://www.prnewswire.com/news-releases/copper-kills-antibiotic-resistant-nightmare-    bacteria-197333411.html
  7. Preventing healthcare-associated infections. (2015, February 20). Retrieved from http://healthtrustpg.com/resources/supply-chain/emerging-technologies-in-infection- prevention/
  8. Salgado, C., Sepkowitz, K., John, J., Cantey, J., Attaway, H., Freedman, K., & Sharpe, P. (2013). Copper Surfaces Reduce the Rate of Healthcare-Acquired Infections in the            Intensive Care Unit. Infection Control and Hospital Epidemiology, 34(5), 479-486.
  9. Scott, R. D. (2009). The Direct Medical costs of Healthcare-Associated Infections in U.S. Hospitals and the Benefits of Prevention. United States Centers for Disease Control and
  10. State Government of Victoria. (n.d.). Antibiotic resistant bacteria | Better Health Channel. Retrieved from       http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Antibiotic_resistant_        bacteria
  11. Transmembrane Potential. (n.d.). Retrieved from http://faculty.ucc.edu/biology- potter/transmembrane_potential.htm
  12. WHO | The burden of health care-associated infection worldwide. (n.d.). Retrieved from http://www.who.int/gpsc/country_work/burden_hcai/en/
  13. World Health Organization. (2011). Report on the Burden of Endemic Health Care- Associated Infection Worldwide. Retrieved from       who.int/iris/bitstream/10665/80135/1/9789241501507_eng.pdf?ua=1