Antibiotics – The Bread and Butter of Modern Medicine
The history of antibiotics
Although we think of them as a relatively recent discovery, antibiotics have been used for centuries to treat infections. Natural remedies such as placing mouldy bread on wounds, soil, and honey were all moderately effective treatment methods before the discovery of present-day antibiotics.
It was not until Paul Ehrlich, a German physician, discovered that certain chemical dyes affected some bacterial cells and not others that the groundwork for targeted antibacterial treatments was laid. In 1909, following experiments which used chemicals to destroy specific types of bacteria, he discovered that arsphenamine was an excellent treatment for syphilis – the modern antibiotic was born!
Of course no article on antibiotics would be complete without mentioning Sir Alexander Fleming and the discovery of penicillin. In 1928, whilst studying influenza, he noticed that he had accidentally left a culture plate of Staphylococcus bacteria open. A fungus had infiltrated the culture, creating bacteria-free zones wherever it touched. This fungus – Penicillium notatum which is commonly found on mouldy bread, is the grandparent of many of the antibiotics we use today.
Initially, production of penicillin was very slow and supplies were limited. However, by the end of WWII, penicillin and related antibiotics were being mass produced by American healthcare companies on a huge scale.
In 1945 Fleming, along with two other scientists who were responsible for further refining the “wonder drug” for mass production, Howard Florey and Ernest Chain, were awarded the Nobel Prize for medicine.
What are antibiotics and how do they work?
According to the Microbiology Society, an antibiotic is “Any substance that inhibits the growth and replication of a bacterium or kills it outright…”
Like all living organisms, bacteria are made up of cells. Harmful bacteria cells enter your body and, if the immune system does not develop antibodies quickly enough, you will get an infection.
Antibiotics normally work in two ways:
1. Stopping harmful bacteria from reproducing, giving the immune system time to develop effective antibodies and eliminate the infection on its own.
2. Breaking down the cell walls of the bacteria – similar to cracking a safe- allowing antibodies to enter the cell and essentially blow it up from the inside (gross!)
What are they used for?
Antibiotics are used to treat bacterial infections such as pneumonia or ear infections. Contrary to common misconception, antibiotics are ineffective against viral infections, i.e. chickenpox or influenza, because these two organisms function in very different ways:
Bacteria: are living single celled organisms that do not need a host body such as a plant or an animal to survive or reproduce. Some bacteria are helpful to humans, such as the bacteria that live in your gut which help with digestion, and some are harmful, such as Staphylococcus.
Viruses: require a living host to survive. They replicate themselves by hijacking the cells of the live organism and manipulating their reproductive functions so that they produce the virus instead of healthy new cells. They basically become part of your body!
Vaccinations are effective prevention method against viral diseases because they allow the body to develop antibodies which can recognise and “remember” the virus, preventing it from gaining a foothold in the body’s cells in the case of exposure in the future.
Due to the widespread, and sometimes unnecessary, use of antibiotics during the 20th century, certain strains of bacteria have become resistant to antimicrobial drugs.
Commonly known as “superbugs” these resistant strains of bacteria, such as Methicillin-resistant Staphylococcus aureus (MRSA), can spread very quickly and are particularly prevalent in hospital environments.
Described by the World Health Organisation as “an increasingly serious threat to global public health that requires action across all government sectors and society”, antimicrobial resistance has the power to seriously inhibit the way that we practice medicine in the modern world. Treatments varying from minor surgical procedures to chemotherapy could be affected if strains of antibiotic-resistant bacteria become more widespread, but is there a solution?
Drug repurposing could provide an excellent solution to the antimicrobial resistance problem. By using drugs which have previously been utilised for immunotherapy or heart disease, or by combining existing antibiotics with these drugs in new ways, a new methodology for the treatment of diseases such as
MRSA could be established.
Antibiotics Unearthed is an initiative set up by the Microbiology Society which aims to involve schools and other learning facilities in the discovery of newer and more powerful kinds of antibiotics using microbes found in soil.