New pill to keep your antibiotics working
TAkINg a new ‘super pill’ at the same time as your antibiotic could help beat superbugs. Antibiotics are widely used to treat bacterial infections ranging from acne to pneumonia. Some target specific strains; others are ‘broad-spectrum’ and can be used against multiple bacteria. They work either by preventing bacterial cells multiplying, so allowing the immune system to fight the infection; or kill the bacteria directly, for example by interfering with the structure of cell walls.
Although antibiotics have transformed medical care, their effectiveness has led to overuse, and now bacteria are learning to defend themselves, rendering many drugs ineffective.
As infections that were previously treatable with antibiotics become resistant to them, doctors are running out of options.
Some strains have become resistant to almost all drugs. Methicillin-resistant Staphylococcus aureus (MRSA), for example, is also resistant to other antibiotics such as quinolones and macrolides. But now scientists have developed a way of overriding resistance to some of the most commonly-used antibiotics.
The secret is a pill taken at the same time, which prevents bacteria breaking the antibiotic down.
The antibiotic group it helps are known as betalactams — which includes penicillin. These target the broadest selection of bacteria.
This group of antibiotics all share a structural feature — a ‘ring’ inside each molecule. This ring is key to the antibiotic’s function, binding to chemicals in the bacteria’s cell walls, preventing them functioning and leading to the bacteria’s death. However, over time, bacteria have learned to develop and release new enzymes called beta-lactamases which destroy the ring, stopping the antibiotic working.
A team from Oxford University have now developed ML302, a compound which binds to betalactamases to stop them reaching the antibiotic ring. Betalactamase inhibitors have been developed in the past to overcome superbugs and restore antibiotic efficacy, but many are specific to a particular antibiotic.
For example, ceftazidime-avibactam, currently being reviewed by the European Medicines Agency for approval, is a combination pill for urinary tract infections made
from the anti- biotic ceftazidime and a beta-lactamase inhibitor called avibactam — but this does not protect against all beta-lactamases, in particular one known as MBL, which no drug so far has been able to overcome.
The Oxford researchers say their new pill which directly targets MBL and other chemicals involved in antibiotic resistance could be more effective, and laboratory and animal studies so far have been promising.
They plan to develop it as a pill to take with any betalactam antibiotic, or eventually develop a single pill containing a mixture of an antibiotic with ML302 for the patient to take more easily. Further studies are planned.
Commenting on the research, Professor Alan Johnson, an antibiotics expert with Public Health England, said: ‘E. coli bacteria that are the commonest cause of bloodstream infection, and another common bacteria called klebsiella pneumoniae, have become resistant to many types of antibiotic. The new compound found by the Oxford scientists may have a role in fighting resistant infections caused by these bacteria.’
MEANWHILE, being overweight could put you at greater risk of infection. A study of nearly 40,000 healthy people showed being overweight raised the risk of hospital treatment for any kind of infection by 50 per cent, according to researchers at the University of Aarhus in Denmark. This included abscesses, skin infections and respiratory tract infections.
Overweight people are also more likely to be on antibiotics, the study found. One theory is that obesity may have a detrimental impact on the immune system, although quite why is unclear.