Scientists have created a method of selectively targeting certain strains of the bacterium E.coli, thanks to work from the researchers at the Centre for Environment, Health and Welfare Research at the Korea Institute of Science and Technology in the South Korean capital Seoul.
Their revised findings were published in this months edition of the journal Applied Catalysis B: Environmental.
E.coli is a usually benign bacterium found in the lower intestine of most endothermic, or warm-blooded, animals. They form part of the human microbiome, assisting in various processes, from removing potential pathogens to aiding digestion, whilst also providing their human hosts the vitamin K2, a compound known for its bone forming benefits and potential to protect from certain heart related conditions.
However, variants of this species exist, known as serotypes. Serotypes are not unique to E.coli, being found in a range of organisms from bacteria to viruses, as well as being used to describe variants of certain human cells.
These distinct variations within the E.coli species are characterised by differences in cell surface antigens, structures on the cell surface of the microbes that are recognised by our immune system, in Layman’s terms, as being “good”, or “inadequate”. Should the cell be recognised as the latter, the immune system will work to remove it for our bodies.
Expansion of such a population can lead to a range of conditions, for example food poisoning.
However, the available treatments have one drawback: they are indiscriminate. Antibiotics and disinfectants do not select which serotype they eliminate, effectively reducing the entire population to zero, including the beneficial “good” variant.
The Korean researchers developed a way of targeting the “inadequate” serotypes, leaving behind a healthy population of beneficial E.coli, using the antigens present on their cell surface.
They developed a bacterial target-specific titanium oxide (TiO2) photocatalyst, according to the paper, capable of selectively deactivating a specific bacterial population.
In order to create such a precise tool, they used an E.coli antibody. Antibodies have the advantage of being unique to a certain antigen, which allowed the researchers to target the bacterial serotype responsible for certain conditions.
The antimicrobial effect of this conjugated antibody/titanium oxide compound showed promising results: ninety per cent of the E.coli were inactivated within fifteen minutes, compared to only twenty percent when titanium oxide was used on its own.
Importantly, the researchers show the antibody/titanium oxide composite had no antimicrobial effect on the non-targeted bacteria, with the additional benefit of titanium oxide being a cheap material to use, and is already in use within the health sector, in products such as sun cream for example.
As a result, we are now potentially able to rid our bodies of pathogenic material without unbalancing the flora of our human microbiome.
This method could become a potent tool in the selective removal of several species of pathogen, using different antibodies, that could not only be used in a pharmaceutical context, helping cure certain conditions, but also in the removal of contaminants in ecosystems and man made structures, whilst leaving the beneficial or harmless organisms undisturbed and able to flourish.
How valuable is this form of “technology” to the human population?