There has been an alarming growth in antibiotic-resistant hospital ”superbugs” such as MRSA, which has become a major international public health issue. The World Health Organization has named antibiotic resistance as one of three major health threats for the future.
What is a superbug?
This is a common term associated with certain bacteria (bugs) that have become resistant to multiple antibiotics over time.
Evolution from bacteria to superbug
Every time bacteria are exposed to antibiotics, there is potential for resistance to evolve. This resistance occurs because of a simple mutation, which deletes a single hydrogen bond from the structure of their cell walls. With this seemingly small change, superbug becomes approximately 1,000 times harder for the antibiotics to disrupt their cell structure, and hence rendering it therapeutically ineffective. Partly humans are responsible for the rise of the superbugs, how?
Over use of antibiotics – Antibiotics should only be used for serious infections. At times Physician’s prescribe antibiotics for non-bacterial infections or for mild infections facilitating evolution of superbugs. Since every exposure of bacteria to these powerful drugs gives them an opportunity to evolve resistance more resistant than ever.
Improper use of antibiotics – Sometimes, patients stop taking antibiotics, when they feel better instead of completing the full course of the medication, thereby fueling bacterial evolution as superbug. Bacteria that survive in the body as a result become more resistant to antibiotic drug. Resistance usually develops over time, wherein the first bacteria to experience resistance may be only partially resistant.
How superbugs spread their genes?
Once the genes for antibiotic resistance evolve, they can spread to non-resistant bacteria, making those bacteria into superbugs as well. The genes for antibiotic resistance are placed on their own little DNA vehicle, called a plasmid. Plasmids are easily transferrable and can carry genes for resistance to multiple strains of antibiotics.
Novel approaches to tackle superbugs
Researchers around the world are developing novel solutions to combat superbugs, let’s take a look at some of them:
Nanotechnology comes handy to counter super bugs – A recent study published in Nature Nanotechnology Journal reveals that scientists from the London Centre for Nanotechnology (LCN) are developing a novel nano-mechanical approach to understand mechanism of how vancomycin work, one of the few antibiotics that can be used to combat superbugs.
They developed silicon-based technology using cantilever sensors. These sensors are “like tiny silicon diving boards having capability to measure dimensions less than the width of a human hair”. These sensors were coated on one side with a layer of mucopeptide molecules present in bacterial cell walls. Research found that as vancomycin attached itself to the cell wall peptide, it generated a surface stress, which contributes to the disruption of the cell walls and hence leads to the breakdown of the bacteria. This surface stress can easily be detected by a tiny bending of the cantilever sensors The LCN team also compared the interaction of vancomycin with both non-resistant and resistant strains of bacteria.
Nanocoating that kill superbugs – Researchers at the University of Bath, UK are working in developing safer, more effective anti-bacterial plastics and coatings that can be used in items such as food packaging, medical devices to wound dressings, and nappies. These new materials have shown promise to be effective common hospital bacterial infections such as MRSA and are safer than existing...
anti-bacterial based on silver nanoparticles.
Bio-engineered antimicrobial protein in Nisin – Researchers at University College Cork, UK have used bioengineering to alter different amnio acides in nisin, which is antimicrobial protein produced naturally by a bacterium called Lactococcus lactis. Dr Field and colleagues had created a family of variants, each slightly different from the naturally occurring protein. These bioengineered nisin variants are much more capable of combating than the parent molecule against a range of important clinical pathogens including MRSA, VRE (Vancomycin Resistant Enterococci) and the food-borne pathogen Listeria monocytogenes. Nisin is US FDA approved and is used as a natural biopreservative in heat-treated and low-pH foods. It has a long record of safe use and is one of only a few such compounds to have been applied commercially.
Computer to help fight superbug infection – Dr Laurence Leowe, of Edinburgh University’s School of Biological Sciences, UK and his team are using computers to mimic the evolution of super bugs. Their team strives to understand mechanism of growth of bacteria and how they become resistant to antibiotics.
A parallel effort by scientists at University of British Columbia Vancouver, Canada and study presenter Artem Cherkasov call it as a marriage between chemistry and computer science. Using the newly developed computer-aided system, the researchers plan to identify vulnerable cellular components of a pathogen using proteomics (the study of proteins and their interactions).
These scientists will exploit key protein structures by using them into their computational models and, with help of elements of modern ‘artificial intelligence’, will identify drugs that have the highest potential for activity against the target and for antimicrobial activity.
Computer modeling is a huge cost benefit as compounds that rank high in the simulation results can be tested in the laboratory against the pathogen as compared to doing permutation and combinations in the lab to develop such compounds. Cherkasov commented that “The chemical structures of compounds we identify usually look nothing like known antibiotics. But if a compound behaves like an antibiotic in a computational model, it may act as one in a real life”. This would mean that these compounds may not be developed in laboratory without the help of computers. .
Most of research is taking a fundamental approach to tackle super bugs. Eventually, the goal of novel research is to pave the way for the development of more powerful and effective drugs to combat various resistant infections and treat infected individuals. With computers helping to develop unique solutions, we may be able to “Clt-Alt-Del superbugs”.