Bacteria, Antibiotics, and the Resistance Crisis
Bacteria, Antibiotics, and the Resistance Crisis
~ Mridini Manivannan
Introduction:
At any one point during the day, we are surrounded by trillions of microscopic bacteria. The total biomass of all bacteria is higher than the combined biomass of all plants and animals! Bacteria were some of the earliest life forms on Earth. They thrive almost everywhere, in the ground, in the air, in water, on our skin and in our homes too. Most of them are harmless, a few are beneficial, but there are some that cause diseases and infections. The most well-known diseases being, food poisoning by Escherichia coli and Salmonella, Cholera by Vibrio cholerae, Pneumonia, Influenza, and tuberculosis.
Let us take a quick trip back to the year 1928. Death and plague around every corner, helpless doctors and nurses, and the crying faces of those that remain. During, and before this time, almost every bacterial infection would be fatal. People and animals would die from common colds, throat infections and infections arising from cuts or exposed wounds. Ear infections and infections from cuts on legs would lead to deafness or amputation if not death. Treatments were not available to kill the bacteria or help the human body fight against an attack from pathogens, this meant that even surgeries to treat other medical conditions could not take place either.
The world lived in fear of bacteria…until Alexander Fleming accidentally discovered Penicillin, a drug produced by a mold growing on his uncovered petri dish, Penicillium notatum. Fleming noticed that the Staphylococcus bacteria on the dish had been killed where the penicillin drug had been produced, and so, discovered the first Antibiotic.
What are antibiotics and how do they work?
The name clearly suggests the main idea of an antibiotic. Against life. An antibiotic is a substance that is produced by or collected from certain microorganisms like fungi or other bacteria, that can destroy or deter the growth of other microorganisms, mostly bacteria. It does so without harming the non-bacterial cells around it. This is because of the target area of most antibiotics is a cell wall. Bacterial cells have peptidoglycan cell walls which stretch and grow to enable to cell to reproduce and split into another cell. Penicillin and some other antibiotics bind to protein molecules on a bacterial cell wall and prevent the cell from adding on more material as the wall stretches. The wall then becomes weak, and bursts, killing the cell.
Most antibiotics work in this way, by inhibiting cell wall growth. There are however, a few more ways by which antibiotics work:
Inhibiting genetic material formation
Breaking down cell membrane structure or function
Inhibition of protein synthesis and
Blockage of chief metabolic routes
Antibiotics are one of the most vital treatments for fighting life-threatening bacterial infections. They are used widely in hospitals, and in the agriculture and meat industries.
What is antibiotic resistance?
Antibiotic resistance occurs when bacteria are no longer susceptible to the antibiotic, i.e., cannot be killed by that particular antibiotic. This means that the bacteria are resistant, not our body. This is continuously happening; bacteria and some fungi are finding new ways to evade the antibiotics’ effects. Resistant bacteria face no obstructions to growing, multiplying, and causing infection inside the host body even when exposed to the antibiotics. Infections caused by resistant bacteria are extremely hard to nearly impossible to treat (harder to treat than non-resistant bacteria), can be life threatening, or will at least result in extended hospital stays and expensive (sometimes toxic) treatments.
How bacteria develop resistance :
Antibiotic resistance happens due to random changes in its’ DNA, or mutations. These mutations can be picked up from dead bacteria which split open, or other strands of DNA that float around in its’ environment, by a process called transformation. Strands of DNA (plasmids) can also be transferred from one bacterial cell to another through an exchange system called the pilus. The DNA with the favourable trait, resistance to an antibiotic, is passed to another bacterial cell. This process is called conjugation. Bacterial cells can gain the mutation by transduction too. In this process, bacteriophages (viruses for bacteria) carry a mutated gene, and when they infect the bacterial cell, incorporate their DNA into the DNA of the bacteria. There is also a chance that one bacterial cell mutates of random and ‘accidentally’ becomes resistant to an antibiotic. This 'accidental' survival, will allow the bacterium to reproduce by binary fission, passing on this useful gene to the next generation.
If even one bacterial cell in a colony has this mutation, when antibiotics are used, all the non-resistant bacteria are killed, providing more space and resources for the resistant bacteria to use, allowing it to reproduce and pass on its’ genes, creating an antibiotic resistant strain.
Why are bacteria becoming resistant?
Overuse of antibiotics is a main reason for antibiotic resistance. In recent times, antibiotics are being prescribed, or taken without prescription, even for common colds and flus, and this provides ample opportunity for resistance to develop, as the bacterial cells are exposed to the antibiotic many times, so killing off the non-resistant bacteria, allowing the resistant ones to thrive.
Resistance also occurs when patients prescribed antibiotics don’t finish their entire course. This happens often when patients don’t have any symptoms of the infection before finishing the course, allowing a small population of bacteria to survive (including resistant ones) and grow, giving rise to a resistant strain.
Poor hygiene and sanitation are also a breeding ground for large colonies of bacteria. There’s then a higher chance for mutations to come up, and so can give rise to resistant strains.
Even taking the wrong antibiotics for an infection can cause resistance to develop. In meat industries, cattle and chicken are kept in tiny and unhygienic conditions, which lead to a large number of infections. To prevent the owners of the company losing money from dying livestock, the animals are given a large amount of antibiotics on a daily basis. Once bacteria become resistant in this way, transfer by consuming the animals, or coming into contact with the people managing the livestock farms.
Present status :
In the past decade, antibiotic usage has increased in India by around 30%, and resistance rates have been getting high too. Resistance against ampicillin in chickens is at a shocking 69.7% resistance rate, and resistance against antibiotic treatment for E.coli and Salmonella has been 16.5%. The global rise in antibiotic consumption has been 65%, from 2000 to 2015.
The most common example of antibiotic resistant bacteria is MRSA (methicillin resistant staphylococcus aureus). This causes a severe skin infection. In fact, Staphylococcus aureus is resistant to a variety of antibiotics, (arising from over-prescription of the antibiotics by medical practitioners) like vancomycin, penicillin, ciprofloxacin, and erythromycin. A lot of infections like pneumonia, tuberculosis and salmonellosis are becoming harder to treat because the antibiotics for them are becoming less effective.
What makes the overuse of antibiotics an even more consequential helath issue, is that new antibiotics are not being discovered. Antibiotics have become non-profitable because they are cheap and too easily available. The antibiotics industry has been facing severe losses in recent years, especially with the rise in resistance rate, so pharmaceutical companies have ceased to dedicate resources towards discovering new antibiotics (discovery is costly but extraordinarily little profit is made).
Even though antibiotics are over-produced, there are some countries (mostly underdeveloped and developing) that still don’t receive enough antibiotics, and here, infection rates are rising, whereas in developed countries like the USA, have access to too many antibiotics, and they are prescribed and taken very frequently, even when unnecessary.
How to combat antibiotic resistance?
The first, and foremost thing, is to ensure that you don’t develop infections in the first place, that way, there won’t be any need for antibiotics. Keeping your hands clean, maintaining personal hygiene, and good waste management in the locality, will help improve sanitation, giving very less chance for bacterial growth, and so, stops infections spreading.
Another way, is to stop usage of antibiotics on farms, and this subsequently means that better and cleaner holding pens must be used for maintaining livestock, so that the animals don’t develop infections, eliminating the need for use of antibiotics.
Unnecessary or over-prescription of the drugs must be stopped. This could include more specialized training for medical practitioners, on the use of antibiotics. This will greatly reduce resistance, making antibiotics more effective against fatal infections.
Developing rapid tests for detection of bacteria causing an infection, will help in fighting it using the correct antibiotics, and at an earlier stage, where there are fewer bacterial cells infecting the body (and a reduced chance of resistant bacteria).
Educating the public also plays an important role in combating resistance. People must be educated on the dangers of using too many antibiotics, as well as knowing when the need arises to take one. Another point that must be stressed, is that a complete course of the prescribed antibiotic must be taken.
Pharmacies must also make sure to only sell antibiotics to someone with a doctors’ prescription, and not hand them out to anyone who asks for them. This plays a major role in preventing unnecessary exposure of antibiotics to bacteria.
It might take a while for the whole world to get these measures in place, but, if whatever that can be done, is done, it’ll be another step closer to ending the antibiotic resistance crisis.
Citations :-
https://ask.metafilter.com/243911/Before-antibiotics-was-every-infection-fatal
The accident that changed the world, what causes antibiotic resistance? , How can we solve the antibiotic resistance crisis? – Ted Ed
https://www.history.com/this-day-in-history/penicillin-discovered
who.int
https://www.indianapublicmedia.org/amomentofscience/antibiotics-target.php
https://www.medwinpublishers.com/APCT/APCT16000137.pdf
https://www.cdc.gov/antibiotic-use/antibiotic-resistance.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fantibiotic-use%2Fcommunity%2Fabout%2Fantibiotic-resistance-faqs.html
https://www.yourgenome.org/facts/what-is-antibiotic-resistance
https://www.hindustantimes.com/india-news/antibiotic-intake-in-india-rises-by-30-in-a-decade-says-report-101612377295525.html
https://pubmed.ncbi.nlm.nih.gov/16218886/
https://microbeonline.com/antibiotic-resistance-origin-causes-mechanism/#:~:text=Antibiotic%20Resistance%3A%20Origin%2C%20Causes%2C%20Mechanism%20and%20Prevention%201,certain%20antibiotics.%204%20Acquired%20resistance.%20If%20the%20presence
~ ♡ Mridini
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