Superbugs versus Quantum dots

Researchers at the University of Colorado Boulder have developed a new nanoparticle treatment involving ‘quantum dots’ to fight against drug-resistant “superbugs”.

What are superbugs?

Bacteria are found everywhere and most of them are harmless but sometimes they cause illness. They are responsible for causing minor infections and sometimes more serious deadly illnesses such as meningitis or pneumonia. Bacterial infections are often treated with a course of anti-biotics. But certain strains of bacteria such as Salmonella, Staphylococcus and E. coli develop resistance to the majority of antibiotics commonly used today. Such strains of bacteria are referred as “superbugs”.

Antibiotic resistance is a naturally occurring phenomenon that cannot be stopped but can be slowed. Over a period of time, bacteria adapt to antibiotics that are designed to kill them and change their structure to ensure their survival. It means previously standard treatments for bacterial infections become less effective and in some cases become fully ineffective.

Certain actions that accelerate the growth of antibiotic resistant bacteria include overuseor misuse of antibiotics, not following the full course of anti-biotics, having poor infection prevention and control practices, living or working in unsanitary conditions, and mishandling food.

How threating are “superbugs”?

In 2014 itself, the World Health Organisation (WHO) has identified antibiotic resistance as one of the greatest global health security threat. Around the world, there are millions of infections caused by superbugs every year. It is estimated that antibiotic-resistant bacteria infect about two million people and kill at least 23,000 people in the US each year. There is no data available for India but the country is the world’s largest consumer of antibiotics and has emerged as a leading hotbed of untreatable bacterial infections with their threat doubling over five years.

How Quantum dots technology fight against “superbugs”?

Efforts to fight against “superbugs” have consistently fallen short as the bacteria develop immunity to common antibiotics. The new technology using quantum dots, however, could offer some hope.

Quantum dots are essentially very, very tiny man-made crystals. They are 20,000 times smaller than the width of a human hair. These light-activated nanoparticles resemble semiconductors used in electronics. In the dark, the quantum dots remain inactive. By exposing to light, quantum dots are energetically “excited.” These light-activated quantum dots can be injected into the human bloodstream and kill the targeted drug-resistant bacteria cells. By changing the wavelength of light, new therapy can be created dynamically. It means when superbugs try to adopt and fight the therapy, we can come up with a new therapy by changing the wavelength of light to which quantum dots are exposed. Thus the fight against superbugs is faster in response to adoption of bacteria.

It is not the first time that nanoparticles have been used to fight bacteria. Previous research has shown that metal nanoparticles such as those crafted from gold and silverare effective against antibiotic-resistant infections, but at a cost: indiscriminate damage caused to surrounding cells in addition to the infection. In contrast, the quantum dots can be adjusted to particular infections. This specificity may therefore help avoid the likely side effects of other superbug treatment options.

In a laboratory trail, the quantum dots destroyed 92% of drug-resistant bacteria. They killed 9 of 10 drug-resistant bacterial cells grown in a laboratory culture and resistant to all known antibiotics. The future clinical trials will determine the success of the technology.


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