Unless you have missed the countless number of headlines over the past few years about MRSA and hospital superbugs, you are probably aware that antibiotic resistance is a huge problem in healthcare at the moment. It brings with it visions of a post-apocalyptic world of widespread plagues of death and destruction and strong desire to constantly wash your hands the moment you enter a hospital. This brings the question, how real is this problem?
The bad news is that it is very real. Around the world a plethora of diseases from cystitis to TB have shown levels of resistance to our current drugs arsenal, even those we have kept back to use as a last resort. The even worse news is that in terms of new drugs in the pipeline, the well is beginning to dry up. If infectious disease is a war, we are definitely losing.
Bacterial resistance is a problem which has been become more widespread year on year. It is caused by a build-up of mutations in bacteria which stops the antibiotics from working properly, no longer killing or stopping the growth of the germs. This is generally caused by the over prescribing and misuse of antibiotics, such as GPs prescribing the use for viral infections, or patients not finishing the course of their prescribed drugs. It is also caused by the widespread use of antibiotics in agriculture to promote growth in cattle. This has created an environment where pathogens are constantly meeting and combating low levels of antibiotics, allowing the favouring of resistance strains over susceptible ones.
Traditional antibiotics may no longer be a viable option, this has sparked a search for alternatives to our current drugs, which work in other ways than simply killing the bacteria, and the good news is that there is a lot of promising research currently in different stages of development. One avenue that is showing potential is that of anti-adhesion therapies. These are drugs which prevent bacteria from gripping to the cells of the body. If they cannot grab the body, they cannot overcome the strategies we have evolved to stop them colonising us, such as the mucus in our airways or the flushing out of germs by urine in the urinary tract. This means they can’t colonise our bodies in high enough numbers to cause us harm. These anti-adhesion drugs which prevent bacteria from attaching to host cells do not put any selective pressure on the bacteria and therefore are not likely to induce resistance meaning that they have high potential for use in the dystopian future we all fear.
There are a large number ways by which we can stop bacteria from attaching to use. These therapies use different means all to the same end, i.e. to alter the interaction between bacteria and patient so that bacteria no longer stick efficiently to cells. Listed below is just a small sample of strategies under investigation.
So, anti-adhesion strategies are not a new idea. Cranberry juice has long been used as a home-made solution to urinary tract infections. This has been shown to be effective in clinical research, however the downside is that this result is less then consistent and there is still a great amount of debate about how it actually works. A component of cranberries and related berries has proven itself as an inhibitor of bacterial attachment, and the high sugar (specifically fructose) content of cranberry juice can work block the ‘arms’ of bacteria, known as fimbrae which grab cells. For those who aren’t big fans of cranberry juice, there is more good news: this anti-infection effect on bacteria is not limited to cranberries; in fact, new research has identified compounds from several other plants including tea and red wine.
On a less appealing note for you personally, there is also evidence that suggest that breast milk may contain a cocktail of ingredients that can prevent bacteria attachment to the recipient. Breast milk has been shown to contain hundreds of proteins, sugars and antibodies, some of which may be affective anti-adherent compounds against a myriad of diseases. This makes evolutionary sense, as providing infants with ‘anti-adherence milk’ gives them a regular protective coating of the digestive system at a time when the immune system is not yet completely up and running and the children are at risk from so many infections.
An alternative strategy is the use of probiotics, which uses non-harmful species of bacteria to fight the harmful kind. In the battle to colonise our body, this strategy is akin to sending reinforcements to the good guys. Commonly used species include lactobacilli and bifidobacteria, which can be added to foods like yogurt. This medical use of probiotics is currently being trialled and is showing some success against a wide number of infections, ranging from food poisoning to vaginosis to stomach ulcers.
The final questions we should ask are: are these therapies are as efficient as antibiotics? Are they just going to generate more complex resistant bugs? Would we be better off concentrating all our efforts on just searching for new antibiotics? Unfortunately we can’t answer this, at least not by ourselves. What we do know is that we are entering a post-antibiotic era. The rule book has changed and science may need to start playing catch up.