Antibiotic Resistance: back to the Dark Ages?


By far the biggest killers in today’s Britain are cancer and circulatory disease. Of the 501, 424 people who died in 2014, 29% died of cancer and 27% from heart attacks plus strokes. There is no doubt as to why charities seeking a cure for these scourges attract so much public support.

By contrast, leaving aside ‘flu and pneumonia, which mainly kill the already weakened elderly and infirm, infectious diseases account for a mere 0.6% of deaths. Your chances of being cut down by one of these in your prime of life is comparable with that of the threat from road traffic accidents or suicide. The reason we are dieing largely from heart disease and cancer is not because they are becoming more virulent, then. It is simply because we are living longer. Whereas in 1900 the average life expectancy in this country was just 48, now it is 81.

Antibiotics, the drugs used to treat bacterial infections, are a recent invention. Alexander Fleming stumbled upon them by accident in a London laboratory in 1928, though the first, penicillin, only went into mass-production in 1944. When it did so, it reduced at a stroke the number of deaths from infections, making hospital operations safe, battlefield wounds less fatal, and many serious diseases treatable.

Bacterial resistance to antibiotics emerged as a problem in the 1950s, but it has now become critical. Resistant bacteria have the ability to transfer their resistance to other species as well as passing it on to their offspring. So, once established, resistance to a particular antibiotic spreads rapidly, and bacteria with multiple resistances emerge. By 2004, bacteria resistant to almost all known antibiotics had appeared, while in 2015, bacteria resistant even to the”antibiotic of last resort” appeared in southern China. It is expected to spread to the west shortly.

In April 2014, the World Health Organization (WHO) sounded the alarm on this topic in no uncertain fashion. It spoke of a “major global threat” from such antibiotic-resistant bacteria, and an imminent return to a pre-antibiotic era, where people regularly die from the simplest of infections. If and when this happens, you would be far more likely to die from sepsis following a cut, or from airborne or waterborne bacterium, and less likely to live to an age when cancer and heart disease are a concern.

There is, though, a glimmer of light on this dark horizon. Traditional antibiotics are developed from defensive chemicals produced by fungi and bacteria. However, our own cells also produce chemicals that attack bacteria. They are short proteins (peptides) produced on our own cellular protein-assembly machines, called ribosomes. From this comes their acronym, RAMP antimicrobials (ribosomally synthesized antimicrobial peptides). These antimicrobials carry a positive electrical charge on their molecules and are attracted to the negatively charged outsides of bacterial cells. Once attached to the bacteria, they punch holes in the bacterial wall or membrane, killing the cell.

These natural defence molecules have been around for millions of years, during which time bacteria have failed to develop effective resistance to them. So, if this is the case, and if effective artificial mimics of natural RAMPs can be made, we may yet avoid a potential return to the dark ages of pre-antibiotics.

Bacteria, the discovery and action of antibiotics, and the emergence and spread of resistance, are all covered in depth in the new A level Biology course recently launched by Oxford Open Learning. You can find out more about the course here: http://www.oxfordhomeschooling.co.uk/subject/biology-a-level/

 

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Philip West studied Natural Sciences at Cambridge and taught for many years in Yorkshire and London. He is now a writer, editor and tutor, and also an examiner for Cambridge International Examinations. He is the course writer for all of the Oxford Open Learning science courses, including the brand new A Level Biology course.

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