What if your antibiotics stop working?
If you are aged 50 and above, you are indebted to antibiotics. The discovery of antibiotics has been a miracle of modern medicine, dramatically extending the life-span of human beings. But, if you ever thought you needed antibiotics for your cold, here’s what you should be receiving!
Antibiotics kill bacteria, and bacteria only! These chemical weapons have done a good job so far in keeping infections at bay
Most bacteria do not harm us, only a few of them are pathogenic and cause infections.
But, the choices of effective weapons available to doctors for treating these infections is rapidly decreasing as bacteria have evolved resistance towards the strongest antibiotics, earning themselves the moniker: Superbugs
Superbugs are much stronger, and harder to kill. In November 2015, a report was published in the medical research journal The Lancet, describing a gene in a bacteria, E. coli, capable of neutralizing the effects of Colistin. It is one of the few antibiotics that is effective against some unyielding infections, also known as The Last Resort antibiotic.
The antibiotic resistance gene, mcr-1 residing in a plasmid inside E. coli, a bacteria normally found in gut, was first found in farming pigs and supermarket meat in China. But, a flurry of recent reports suggest that the superbug bacteria has found its way from pigs to humans. Reports from several countries, Denmark, Germany, Spain and United States and many more suggest that the superbug is very rapidly spreading and infecting the human population.
The bigger threat is that once antibiotic resistance has evolved in a certain species of bacteria, it can easily spread to other infectious bacterial species. So, while E. coli by itself may not cause dreadful infections in humans, other bacteria can!
The appearance of superbugs has become a major concern for public health safety, and an important topic of scientific investigation these days. The video (aside) shows how bacteria can adapt and survive in higher doses of antibiotic. The rims (left and right) of the dish are free of any antibiotic, and each section has 10-fold higher amount of the antibiotic with the centre of dish containing 1,000-fold the amount compared to the outermost rims. These fascinating visuals show how bacteria slowly grow and evolve through the dish, and are able to adapt and occupy areas with higher concentration of the antibiotic. This is evolution in action!
So, how does antibiotic resistance happen? How does it spread from one bacteria to another?
When bacteria are exposed to antibiotics, majority of them are killed. Sometimes, few bacteria can survive as they are able to neutralise the effect of the antibiotic due to a mutation in its genetic material, giving rise to a superbug gene.
When a bacterium is immune to the effects of the antibiotic, the DNA material that codes for the resistance properties can transfer to other bacteria by a process called as horizontal gene transfer (aside). Mobile genetic material, called plasmids, that harbour the superbug gene is transferred to bacteria of other species. This process, equivalent to sexual reproduction in bacteria requires the formation of a tube known as pilus, that acts as bridge between the two bacteria.
Other species of bacteria such as: Clostridium difficile that causes life-threatening diarrhea, or Neisseria gonorrhoeae that causes gonorrhea, can acquire the superbug gene. As a result, these menacing infections might become harder to treat. This is already a major concern for tuberculosis treatment.
Written by Alok Jaiswal