Geoff Foster: Sir Alexander Fleming warned of penicillin’s limitations

Sir Alexander Fleming . Picture: Getty
Sir Alexander Fleming . Picture: Getty
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We often hear of the global advance of “antibiotic-resistant superbugs”, or antimicrobial resistance (AMR) in scientific parlance, and it is a threat we cannot underestimate.

Antimicrobial resistance occurs when microorganisms which cause infections become resistant to the medicine used to kill them, as more and more do. Infections such as MRSA and C diff are now resistant to many antibiotics. These and other resistant bacterial threats are not restricted to humans; they can also occur in animals, including livestock and pets.

Animals and humans constantly pass bacteria (including resistant strains) back and forth, as well as moving them around the environment. There is an increased prevalence of resistant organisms all around, with greater opportunity for resistance genes to pass to other, sometimes more harmful, bacteria. Moreover, antibiotics also kill beneficial bacteria, so called “good bacteria” which actually help fight off infections.

The political world is alert to this growing problem. The UK government’s Chief Medical Officer ranked AMR alongside terrorism and climate change as major global concerns, while the World Health Organisation has said “resistance to common bacteria has reached alarming levels in many parts of the world and that in some settings, few, if any, of the available treatment options remain effective for common infections”.

When I entered the field of microbiology in the 1970s, bacterial infections were cured by a constant flow of new antibiotics coming to market and resistance was less of a threat, yet today we stand on the brink of returning to a pre-antibiotic era when vast numbers of people died of common infections – how did we reach this situation?

Sir Alexander Fleming’s discovery of penicillin in 1929 remains one of the most notable scientific achievements of all time. Yet, even in his Nobel Laureate Acceptance speech, he warned of the dangers of resistance to penicillin and its misuse.

“The time may come when penicillin can be bought by anyone in the shops. Then there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug make them resistant,” he said on 11 December, 1945

His concern was underdosing, because bacteria that survived penicillin treatment may develop resistance. Today, the over and misuse of antibiotics around the world has fuelled the growth in AMR. In some areas, however, the use of these treatments is now strictly controlled. The NHS has implemented antimicrobial stewardship programmes and antibiotic usage has reduced significantly. Some infections are left to run their natural course, permitting clearance of the organism from the patient and reduced opportunities for AMR developing. Certainly, the days when a child went to their GP and was instantly prescribed an antibiotic are a distant memory.

There are also well-established responsible use guidelines in place for vets, however, the consistency with which these are applied is unknown. The development of new antimicrobial medicines has slowed dramatically over the last 30 years and any new ones are likely to be reserved for critical (human) infections, as may become the case for some of those currently in use. So it is essential vets take steps to reduce the development of resistance and preserve the drugs available.

When antimicrobial treatment is deemed necessary, it is sensible to use an antibiotic likely to eliminate the infection, while minimising impact upon beneficial bacteria. To ensure this, a sample should be tested at a veterinary laboratory. Such good practice ensures animals are treated effectively and suffering reduced. It also allows monitoring of resistance at a national level, so aiding in managing the responsible use of antibiotics. Such information collected by Scotland’s Rural College was included in the recent 2013 UK One Health Report. The report is a part of the UK Five Year AMR Strategy (2013-2018), which outlines that the continual collection of AMR data from humans and animals is essential if we are to succeed in tackling the high priority issue of AMR.

Geoff Foster is SRUC Veterinary Centre Manager