Attacking antibiotic resistance
The growing problem of antibiotic resistance has been in the headlines recently, and the need for new strategies to tackle infections remains as large as ever. Here the MRC evaluation team’s Ellen Charman rounds up some approaches that MRC-funded researchers are taking to tackle the problem.
Picture a world where a cut finger could kill you. You don’t have to look too far ― before the discovery of antibiotics just 80 years or so ago it was common for women to die from post-childbirth infections, and diseases such as tuberculosis were huge killers.
But the return of this world isn’t confined to the realms of science fiction. As bacteria become more resistant to antibiotics, there’s a very real possibility that the drugs which we’ve come to rely on in modern healthcare may become obsolete.
Since Sir Alexander Fleming accidentally discovered penicillin growing on a petri-dish of bacteria, antibiotics have saved the lives of millions. Their discovery is seen as one of the most important medical achievements of the 20th century, and in fact topped the MRC’s Centenary Poll of medical advances with the greatest impact.
But overuse and misuse has contributed to bacteria’s growing resistance to antibiotics. Sir Alexander Fleming himself, on collecting a Nobel Prize for his discovery, predicted the dawn of this battle, saying: “It is not difficult to make microbes resistant to penicillin in the laboratory by exposing them to concentrations not sufficient to kill them…”
England’s Chief Medical Officer Professor Dame Sally Davies warned earlier this year of the “catastrophic effect” of antimicrobial resistance and urged immediate action from global leaders before deaths from routine surgery once again become a common occurrence.
So what is the answer? MRC scientists are pursuing a range of approaches to tackle the problem.
Research is focusing on improving understanding of a bacterium’s cellular processes ― how it survives, causes disease and how it becomes resistant. For example, Dr Andrew Edward from Imperial College London has recently discovered that the transformation of the bacteria Staphylococcus aureus to its antibiotic-resistant form occurs as part of its natural life-cycle.
Identifying new bacterial components and systems for a drug to attack is also important. Dr Gérald Larrouy-Maumus at the MRC’s National Institute of Medical Research (NIMR) has recently identified how tuberculosis obtains the nitrogen it needs for growth within a host cell during infection. He demonstrated that the amino acid aspartate is a primary source of nitrogen and so the mechanism for getting aspartate into the bacterial cell is a potential drug target.
Whole genome sequencing of bacterial samples could also lead to fewer antibiotics being used ― a more specific diagnosis would allow the use of a more specific antibiotic. This sequencing also means that researchers can track the spread of infection, helping with infection control and therefore prevention. This is what Professor Sharon Peacock at the University of Cambridge has done to track MRSA and researchers at the University of Oxford have done to track fellow hospital ‘superbug’ Clostridium difficile.
We’re also investing in new antimicrobial therapies, such as vaccines. Professor Simon Foster at the University of Sheffield has developed a vaccine for Staphylococcus aureus, which will shortly undergo safety testing by means of an award made through the Biomedical Catalyst. And Dr Martha Clokie at the University of Leicester has developed a bacteriophage ― a virus that effectively ‘eats’ bacteria ― against Clostridium difficile.
Let us hope that this renewed focus means that fears of a cut finger remain consigned to the history books.