What is antibiotic resistance?Antibiotics are medicines used to prevent and treat bacterial infections.
Antibiotic resistance occurs when an antibiotic has lost its ability to effectively control or kill bacterial growth and is a consequence of bacterial natural selection. So when antibiotics are used to treat an infection, and the bacteria aren’t killed, they are harder to manage afterwards due to developing resistance to the antibiotics.Why is it a problem?Antibiotic resistance is still a massive problem throughout the world mainly because although some level of antibiotic resistance occurs naturally as bacteria adapt to survive, misuse of antibiotics in both animals and humans is making this problem progressively worse· Antibiotic consumption has been linked to the emergence and dissemination of resistant bacteria strains as demonstrated by epidemiological studies.
· Studies have shown that in 30-50% of cases, treatment indication, choice of agent, or duration of antibiotic therapy is wrong. If bacteria are exposed to inappropriate antibiotics, or antibiotics that have been administered for too long, this can lead to bacteria developing a gene coding for resistance more easily.· Extensive agricultural use is a significant cause of the growing resistance in superbugs. The Guardian published an article on the shortfalls of UK supermarkets in their fight against preventing antibiotic consumption from animals to humans.· Since the early 2000s, pharmaceutical companies have been producing more treatments for cancer and chronic disease, as opposed to essential antibiotics. Current pharmaceutical regulations mean that clinical trials are expensive and time-consuming, and it often takes years before a trial drug becomes widely available. Both the reduced economic incentives and challenging regulatory requirements have led to very few new antibiotics being available to treat a wide range of diseases, from community-acquired UTIs to pneumonia. What are the main issues concerning antibiotic resistance?Antibiotic resistance is emerging and spreading globally, as it can affect anyone, of any age, in any country.
It threatens our ability to treat common infectious disease – prolonging suffering for children and adults. As a result of antibiotics become less effective, a variety of infections, such as blood poisoning, pneumonia, tuberculosis, gonorrhoea, and foodborne diseases, are becoming increasingly difficult to treat. Moreover, antibiotics are usually given to patients before and after surgery to prevent bacterial infections. However, with the rise of superbugs, it will mean an increased risk for operations such as caesareans, hip replacements and appendix removal, and also the treatment for cancer patients, who are given antibiotics for chemotherapy. Besides antibiotic-resistant bacteria being more difficult to kill, they are also more expensive to treat. So antibiotic resistance leads to “higher medical costs, prolonged hospital stays, and increased mortality”, the world health organisation states, “It is one of the biggest threats to global health, food security, and development today.” Prevalence of MRSA (Methicillin-Resistance Staphylococcus Aureus) colonisation in the UK population currently lies between 1-3%. Currently, there has not been an effective method that can be used to control MRSA infections.
There was an outbreak of a “Super Gonorrhoea” STI, which in rare cases lead to infertility and blood poisoning. The bacterium responsible for causing the disease, Neisseria Gonorrhoeae, became resistant to Azithromycin, meaning that the only drug able to treat it was Ceftriaxone. However, widespread use of the second line drug raised fears that it would also become resistant to that, leading to an untreatable illness. What are the current treatments?Just as the saying goes, prevention is the best cure, so the best way to prevent antibiotic resistance is to avoid the illness in the first place. Vaccinations are also now being developed to target the immune response, improving its effectiveness. In the future, it may be possible to create further bacterial vaccines, in addition to those currently used for Tuberculosis and Typhoid, amongst others. Alternating therapy is a method involving the use of pairs of drugs, which are cycled during treatment for a bacterial infection.
Evidence suggests that alternating treatment can be used to treat bacterial infections successfully. Developments of resistance of drugs were slowed by 40% and above when using a combination of drugs to target the bacterium Staphylococcus Aureus compared to when using just one drug. There are limited solutions for tackling antibiotic resistance, so there is a dire need for to invest in research and development of new antibiotics, vaccines, diagnostics and other tools, to prevent and control the spread of antibiotic resistance.Can nanoparticles be used in fighting antibiotic resistance?Nanoparticles are tiny matter 1-100 nanometres in size. They have been demonstrated to have many beneficial uses in the field of medicine, and thus there has been a wide range of applications of nanotechnology in healthcare under development. One potential application is the use of Nanoparticles in improving antimicrobial techniques.
The use of quantum dots to treat antibiotic-resistant infectionsResearchers at the University of Colorado Boulder were working on developing quantum dots, which are small crystals of semiconductors made of cadmium telluride- a stable crystalline compound in photovoltaics that we often use to make phones and computers. Besides helping with imagining cancer research, quantum dots have shown some promise in being used to combat superbugs that are resistant to antibiotics, as it successfully killed 92% of drug-resistant bacterial cells in a lab-grown culture. The quantum dots (about the width of a strand of DNA, 3 nanometers in diameter) release a chemical called superoxide that makes bacteria more vulnerable by interfering with the bacterium’s metabolic and cellular processes.
In this study, antibiotics with quantum dots were 1,000 times more effective at fighting off bacteria than antibiotics alone. According to Nagpal, using nanoscale semiconductors could create highly specific intercellular interactions that only target the infection. Although metal nanoparticles can be useful at combating antibiotic-resistant diseases since they can induce cell death, the toxicity is nonspecific so it can damage surrounding cells as well.
Unlike metal nanoparticles, the quantum dots can be used to target particular infections because the dots stay inactive in the dark, but can be activated by exposing them to light. Essentially, the electrons of the quantum dots react to green light at a particular frequency, bonding with oxygen molecules in the body, resulting in the production of superoxide. Bacteria absorb the superoxide readily, messing up their internal chemical processes, such as their ability to produce energy and grow. So they become unable to fend off antibiotics. In the study, a range of test samples were prepared by mixing different quantities of quantum dots into varying concentration of each of five antibiotics. They then added them to five strains of drug-resistant bacteria, including E-Coli, MRSA, and Salmonella. After 480 tests with different quantum dots/antibiotics/bacteria combinations, the results showed that more than 75% of the samples with quantum dots were able to inhibit bacterial growth or kill the bacteria at lower dosages of antibiotics. This allows researchers to selectively alter and kill the infected cells just by modifying the wavelength.
So just as the superbugs can quickly adapt and render antibiotics ineffective against them, we would also be able to promptly modify these quantum dots to come up with a new therapy. When activated, the dots produce just enough superoxide that is toxic to bacterial cells, but harmless to the host’s cells. The specificity of the quantum dots may help reduce or eliminate the potential side effects of other treatment methods, as well as provide a step forwards in the for future development and clinical trials in the fight against antibiotic resistance. They could theoretically be so effective, that they would only require a one million-times smaller dose than traditional drugs. Quantum dots are quickly and cheaply manufactured so producing them to treat infections on a worldwide scale would cost just a few cents (or less) per dose. However, one limitation of this study’s use of quantum dots is that it can only be used for surface issues since the light that activates the process has to come from somewhere, and it can just radiate through a few millimetres of flesh.
The team has been attempting to design alternatives, such as nanoparticles that absorb infrared light instead, as infrared light can pass through the body and could be used to treat bone and deep tissue infections. This research is still in its early stage and requires further studies and clinical trials before these quantum dots can be administered to patients. At the same time, even if new treatments are developed, without behaviour change, antibiotic resistance will remain a challenge. Ultimately, awareness of antibiotic resistance needs to be raised, so that both healthcare professionals and the public in all parts of the world can work in collaboration to combat antibiotic resistance. Besides being more cautious when prescribing and using antibiotics, we should also attempt to reduce the spread of infections through vaccination, good hand washing practices, food hygiene and practising safer sex. Join the fight against antibiotic resistance and become an antibiotic guardian now!