Antibiotic resistance has been in the news. It is perhaps a far greater threat than the terrorist threat. It is already estimated to cause 5,000 deaths a year in Britain. No new classes of antibiotics have been developed for 25 years: the pharmaceutical industry has focused on more lucrative types of drug that are taken daily for years rather than antibiotics which because they are taken as a short course, are therefore less profitable. Dame Sally Davies, The Chief Medical Officer has warned that that resistance could ultimately make major operations and many treatments we take for granted too dangerous, and medicine will be forced back to the dark ages as effective antibiotics will not be available. She suggested last year that governments step in to help research funding. David Cameron has agreed to set up an independent review and discussed the problem at the G8. Last month antibiotic resistance was chose as the subject for the £10 million Longitude Prize which was set up to tackle the ‘major challenge of the time’.
Infections [communicable diseases] used to be the commonest cause of death but now thanks to better sanitation, immunisations, and antibiotics they account for 7% of all deaths. The major causes of death in the UK are now what we call non communicable diseases such as heart attacks, cancers and strokes. [See my book Medical School Interviews The Knowledge p64] It would be appalling if antibiotics stopped working. As Dame Sally said ‘We won’t be able to do a lot of our cancer treatments or organ transplants’. People may die of a simple scratch again.
Why is antibiotic resistance increasing?
1. Over use of antibiotics by people. We do not need to use antibiotics for simple infections, many of which are viral and do not respond to antibiotics. If people do not take the full course or miss tablets it may allow resistant strains to grow by not completely killing all the bacteria. Although doctors in the UK are rightly criticised for over prescribing antibiotics they actually prescribe fewer than in most countries. It is also possible to buy antibiotics from pharmacies in most countries in the world without a prescription.
2. Overuse of antibiotics in farming. Animals actually consume more antibiotics than people. Infections are common in overcrowded dirty conditions so they are often given in small doses in feeds [this is cheaper than providing better conditions]. They are also used as growth promoters; if they are added to feeds they reduce the amount of bowel bacteria and animals put on more weight. In one study of Chinese pig farms Chinese and American scientists detected 149 unique resistance genes. The top 63 antibiotic-resistance genes were found in concentrations between 192 times and 28,000 times higher than “control” samples of manure or soil that were antibiotic-free. Salmonella, a bacterium found in poultry and infects humans who may eat undercooked chicken [barbecues are common culprits] has become increasingly resistant to antibiotics in this way.
3. Antibiotics are expensive to develop. There is not much incentive for drug firms to develop new antibiotics as they tend to be taken for just a few days while a new blood pressure pill may be taken continuously every day by a patient. Dame Sally said action was needed to overcome this “market failure” and stated that this should be taken up by the ‘Innovative Medicines Initiative’ – an EU funded body whose aim is to promote the development of new medicines. David Cameron had a similar discussion with G8 leaders [ the leaders of the richest 8 nations]
Leading microbiologists say that there are only a small number of ways of attacking bacterial cells and these are being exhausted. If we squander the antibiotics we have we will not necessarily have new antibiotics to take their place. There have not been any new antibiotic groups since the 1980s.
What can we do?
1. We should reserve antibiotics for serious infections. I often think of Tolstoy who said ‘Time and patience cures most things’- unfortunately many patients don’t have the time to be ill and certainly not the patience! MRSA [methicillin resistant staphylococcus] and clostridium difficile rates in hospital have decreased in hospital since better practices were introduced but unfortunately there has been a rise in E coli and other infections.We need to look very carefully at farming practices. Antibiotics should not be used to make up for shoddy, dirty farming practices.
2. Value our ‘good bacteria’. About 90% of the cells in the human body are supposed to be bacteria. We have trillions of bugs living in our gut and on our skin. Most of these cause no harm and some are helpful. Their presence stops bad [pathogenic] bugs growing by depriving these pathogenic bacteria of space to grow. We know that over washing can lead to more rather than less skin infections and it is common after a course of antibiotics to get other infections such as thrush [a yeast infection which grows into the space that had been occupied by good bacteria now killed off by antibiotics.]
Many teenagers may be taking antibiotics for acne. These work against Propionibacterium acnes bacteria which cause inflammation in sebaceous glands of the skin leading to spots. Recent studies seem to show that those teenagers without acne still have Propionibacterium acnes but of a strain that does not cause inflammation. Perhaps in the future a treatment using this ‘good strain’ may become available. [J. Bacteriol. January 2012 vol. 194 no. 1 202-203]
Probiotics– These have been shown in some studies to be helpful in treating diarrhoea. They contain harmless bacteria like lactobacilli which are supposed to displace harmful bacteria. Studies have shown that taking capsules of ‘healthy faeces’ also helps certain types of diarrhoea by recolonising the gut with normal healthy bacteria!
3. Bacteriophages are viruses that infect bacteria. They have been used for over 90 years as an alternative to antibiotics particularly in Eastern Europe and the Soviet Union. They are usually very bacteria specific – only acting on one type of bacteria. There has has been increased interest in them because of antibiotic resistance and since 2006 several types have been licensed including one against MRSA! However they are still not in common use
There must be a global, coordinated campaign. In some parts of the world antibiotic resistance is much greater. New Delhi Metallo-beta-lactamase-1 (NDM-1) is thought to have emerged in India where poor sanitation and antibiotic use have helped resistance to spread. This multi-resistant bacteria has been found in the Delhi drinking water but due to international travel, cases have been detected around the world including in the UK. Britain misuses antibiotics much less than many countries where they can be bought cheaply without prescriptions.