Antibiotics, use and misuse
Just about everyone knows antibiotics have revolutionised treatment for infections and how previously fatal diseases can now be successfully cured. The story behind Fleming’s discovery of penicillin has become a medical legend, rated alongside Jenner’s development of the first vaccine against smallpox. With the advances made in pain relief and anaesthesia over the last 100 years, more complicated surgical techniques could be developed, paving the way for the multi-disciplinary method of modern medicine.
The central role of antibiotics in current veterinary and human medical practice has, unfortunately, led to a degree of complacency. We have been guilty of taking them for granted. Although there are side-effects and adverse reactions associated with their use, antibiotics are regarded as first-line treatments for many presenting complaints, not all of them caused by bacteria. As a result, bugs get a good look at their arch-rivals and have developed a number of strategies to avoid their effects. This resistance has grown over the years and now threatens to make many antibiotics useless, forcing us to turn to the lesser-used and often less well tolerated medicines.
There are several major reasons why bacteria are winning the battle but basically its evolution. With the very short time to make a new generation (minutes), bacteria rapidly self-select any mutants that are less susceptible to the effects of an antibiotic and so a resistant population can grow very quickly. There are even little circular bits of DNA (called plasmids) that can be passed between bacteria, carrying the genetic information that confers resistance. Even bacteria of different types can swap plasmids so that resistance can be spread from one type of infection to another. Advances in DNA technology has meant that at least we can find out exactly how bacteria become resistant and this knowledge can help us to invent new ways of by-passing that resistance, so making those bacteria susceptible to treatment again.
The fact that natural selection lies at the heart of bacterial resistance to antibiotics means that we will always be fighting against the essential life-force that has shaped life on Earth. The obvious conclusion to draw is we are not going to win this war! Maybe not but we can and must win a few more battles. Research is our weapon, funded by governments and pharmaceutical companies, who need to start moving antibiotic development up the priority list. It all takes a lot of money though, and years of work before a new product is licensed and ready for use. Which means we need to get cracking.
To compliment the strategy of developing new antibiotic drugs we need to try to slow down the rate of resistance. The best way to do this is by using our existing antibiotics more wisely and selectively, by prescribing them only when “necessary”. So how do we know when they are needed and therefore necessary? Well, it’s often not easy because by the time tests prove a bacterial infection (rather than a virus or other disease process) the patient may be too ill to recover even if the right antibiotic is given. What’s more, isolating bacteria can be a bit hit and miss and so a bacterial infection may never be proven. So do we prescribe antibiotics early and possibly inappropriately, increasing the chance of resistance if we are wrong but saving the patient if right? Not surprising that early use (and hence some over-use) is common as the consequences of withholding treatment could be fatal.
So what’s the answer? We need to be more selective in our use of antibiotics and remind ourselves that in most cases, antibiotics complement our immune systems, rather than being the only factor in recovering from an infection. To help our natural immunity, we need to be fit and eat a healthy diet, as true for humans as it is for animals. We also need to invest more in medical research, understandably dominated by cancer and the diseases of ageing but now must address a problem just as pressing. After all, if we and our animals die of septicaemia in early or mid-life, we will have little need for treatments for geriatric problems.
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