X-MINING X-TALK Vol.8 【Part 1】 The Antibacterial Action of Copper, a Metal That Protects Life.

Exploring the potential of copper's antibacterial activity, supported by over 20 years of research at Kitasato University Hospital.

Could you please share how Dr. Sasahara came to engage in research activities in the field of copper’s antibacterial properties?

Before I began my research, almost no one in the medical world was aware that copper possessed antibacterial activity.

Since the Meiji era, copper has been valued as a metal with excellent conductivity, and although there are cases where copper compounds are included in some medications, the medical applications of copper were entirely unknown.

In metals, electrons known as free electrons are always moving around.

One of the properties that arise from this movement of electrons is conductivity, the ability to conduct electricity.
Through preliminary testing, we discovered that besides conductivity, copper also possesses antibacterial properties, especially against bacteria.
This led us to start more specific research on its mechanism and effects.

Specifically, against which microorganisms does copper exhibit antibacterial activity?

In our research, we have found that copper shows excellent antibacterial activity against most of the representative bacteria in the medical field, such as Enterohemorrhagic Escherichia coli O157, Staphylococcus aureus, Salmonella, Campylobacter, and Legionella.
Additionally, it has been demonstrated to have effective results against Human Immunodeficiency Virus (HIV), Norovirus, Influenza virus, and even the novel coronavirus.

While it takes a bit more time for fungi (spores of mold) and molds to be eradicated, copper is effective against them as well, and it also has a lethal effect on protozoa parasites.

Therefore, it can be understood that copper exhibits effects against almost all microorganisms that surround our living environment.

▼Microorganisms for which copper’s antibacterial effect can be expected
• Bacteria: (Enterohemorrhagic Escherichia coli O157, Staphylococcus aureus, Legionella)
• Viruses: (Norovirus, novel coronavirus)
• Fungi: Mold (spores of Aspergillus)
• Protozoa: Cryptosporidium, etc.

Was your connection with the Japan Copper Center also born out of such research?

Our association began in 2001, during research related to Legionella bacteria.

Subsequently, since conducting demonstrative experiments in 2005 to improve the hygiene environment at Kitasato University Hospital through the joint project research “Copper in Health” with the International Copper Association (ICA), we have been collaborating with them on various research activities related to copper for a long time.

The Japan Copper Center is an organization established in November 1964.

Its mission encompasses three main areas: the development and expansion of copper applications, research and studies on copper, and public relations activities.

However, as we do not own research facilities ourselves, we collaborate with universities and research institutions to conduct joint surveys and research.
We have also been involved in various demonstrative experiments with Kitasato University Hospital.

Could you please tell us about the specific content of these demonstrative experiments?

Our hospital was rebuilt in 2014 from the old hospital, but between 2005 and 2007, during the era of the old hospital, we conducted demonstrative experiments by introducing copper products in several locations such as the dermatology ward, the NICU (Neonatal Intensive Care Unit), and the ICU (Intensive Care Unit for adults).

Even after the new hospital opened in 2014, we have continued to investigate antibacterial performance by replacing door handles with those made of copper alloy and wrapping copper foil around the handles of medical PC carts.

As a result, it has been found that the number of bacteria adhering to the surfaces of copper alloy door handles is about one-half to one-sixth compared to those made of conventional chrome-plated door handles.

Ms. Ueno, it seems you have been involved in Dr. Sasahara’s research on copper’s antibacterial properties for a long time.

Yes. I am currently the Deputy Director of the Nursing Department at Kitasato University Hospital. I first met the doctor in my first year as the head of the NICU, where we conducted research on how much Staphylococcus aureus could be found in areas frequently touched by nurses.

Staphylococcus aureus is one of the bacteria that constitute the normal flora of the human body and usually does not pose a significant problem for children with normal immune resistance if it colonizes.

However, Methicillin-resistant Staphylococcus aureus (MRSA), which has acquired resistance and can cause hospital-acquired infections, poses a significant threat to the children admitted to the NICU, especially those with developmental issues.
Therefore, we swabbed areas that these bacteria are likely to adhere to on a daily basis and analyzed the number of bacteria present.

This led us to identify locations where we wondered why there were so many bacteria adhering, and some of these were found to be MRSA.

Where were these bacteria found?

I had somewhat anticipated that areas like the inside doorknobs for visitors’ doors and bed rails would be involved, but bacteria were also detected on computer keyboards, the backside of binders used to record when babies were fed milk, the grip of pens used for recording in binders, the interior near the operation port of closed incubators, and even the floor surrounding the beds.

At that time, floors were regularly cleaned, and doorknobs were wiped down, but keyboards, pens, and binders were not being disinfected.

The children entering the NICU are essentially brought in immediately after birth, so the only contact they have with the outside world is through us.

The discovery that many bacteria were detected from our surroundings was a significant shock.

Of course, disinfection cleaning was being conducted as an infection control measure within the scope considered at that time.
However, the investigation revealed that the contamination control was insufficient.
As part of the contamination control measures, we created prototypes of pens with copper grips and had the nurses use them for about two years to conduct a comparative demonstrative experiment with regular pens.

It was soon confirmed that copper had a dramatic antibacterial effect, and this effect was not diminished even after two years.

Using this pen has made me grow fond of it and become a fan of copper (laughs).
When there’s no place to wash hands, no means to disinfect, but I still want to drink water—during such times, I make it a point to hold this copper pen.

Holding the copper pen, my fingers smell like the metal’s unique scent (laughs).

But there are times when I hold it for about 30 minutes.

It’s truly a “life-saving pen.”