Every time a new antibiotic is introduced, the bacteria evolves and takes a step forward and becomes resistant to that antibiotic. We need to keep coming up with new antibiotics to stay one step ahead of the bacteria.
At Oxford University, Dr Martin Westwell is a chemist who raises serious worries about the increasing resistance to antibiotics that is being seen in Britain.
The problem is principally one for hospitals where increasingly a new "super bacteria" is testing the resources of doctors and medicines to the limit.
Martin says that the problem has been building for some time:
"In the sixties it was noted that lots of bacteria were becoming resistant to penicillin, and that wasn't such a big problem at the time because new antibiotics were coming through, and the outbreaks were only sporadic. Nobody really realised how serious it would get, but now as time's gone on in the 90s, the bacteria have become resistant to a whole range of antibiotics. We've got a list of antibiotics that we can use, and the bacteria have worked their way down the list becoming more and more resistant, until we've only got one or two antibiotics left."
"It's the bacterium called staphlyococcus aureus, that has caused the problem. It lives on all of our skins, and it only causes infection when it gets inside the body. But it’s started to become resistant to so many antibiotics that it's called multiply resistant staphylococcus aureus, or MRSA."
Antibiotics are used a great deal in hospitals, and bacteria have the opportunity to develop resistance. In the last five years or so there has been a five-fold increase in the number of hospitals that have seen MRSA infections in their wards. However not everybody going into hospital is at risk.
"Great care has to be taken in places like burns units, intensive care units, or with people who have gut wounds. Hospitals are really very conscious to stop those people from getting MRSA infections, because their immune systems might not be up to up to fighting the bacteria.
"Hospitals are being forced to take measures to deal with the problem when a new patient goes into a hospital, they assess them to see if they're a high risk person, to see if they might have an MRSA infection, and if they are then they'll keep them in isolation - they'll keep them to one side to stop that MRSA infection going around the hospital."
Where an MRSA infection is encountered the antibiotics which are still effective are few in number. They are much more expensive than simple antibiotics and can cause unpleasant side effects.
Martin calls for much greater care in the way we use antibiotics. Problems can also arise from the use of antibiotics on farms, where they are routinely used for two reasons:
"Antibiotics are used in farming, not just to treat disease but growth promotion as well. So what they do is they add antibiotics to the feed that the cattle eat, because this kills the bacteria that live in the stomach of the cattle. The cattle take more nutrients from the food, it's not digested by the bacteria, so the cattle grow faster per kilogram of food fed to them. Because of this ongoing use of antibiotics it means that these bacteria have got the chance to evolve and become resistant again. And so cattle in farms really do harbour antibiotic resistant bacteria.
"The problem arises where a harmless, drug-resistant bacterium comes into contact with a disease-causing bacterium which can be treated by antibiotics. If the two then swap secrets the risk is that a super bacteria could emerge".
"In the case of farming, a harmless, drug-resistant bacterium might be living in a farm animal that's been brought about by use of growth promoters. At the same time a disease-causing bacteria might be living on the skin of a human being, and if these two come into contact, by the human and the animal physically touching each other, then this secret-swapping process can occur and the human will have living on them a bacterium that is resistant to antibiotics and causes disease."
Pharmaceutical companies are responding to this threat and governments are attempting to limit the use of antibiotics in the human and animal field. But there is no easy solution.
"It's an arms war in a way, because what's happening is every time we introduce a new antibiotic, a new weapon against the bacteria, they evolve and take a step forward and become resistant to that antibiotic, so we need to keep coming up with new antibiotics to stay one step ahead of the bacteria."