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Scientists at the University of East Anglia demonstrate how the bug responsible for E. coli and salmonella builds an impenetrable wall to keep out drugs
6:00PM BST 18 Jun 2014
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The global threat of antibiotic resistance could finally be tackled after British scientists discovered a chink in the armour of deadly bacteria.
Health experts have warned that within 20 years even routine operations such as hip replacements and organ transplants could be deadly because of the risk of infection.
But now scientists at the University of East Anglia have discovered how the bug responsible for E. coli and salmonella builds an impenetrable wall to keep out antibiotics.
They believe that within a few years they could develop a drug which switches off the wall-building mechanism, making the bacteria vulnerable.
“It is a very significant breakthrough,” said Professor Changjiang Dong, from the University of East Anglia's (UAE) Norwich Medical School.
“This is really important because drug-resistant bacteria is a global health problem. Many current antibiotics are becoming useless, causing hundreds of thousands of deaths each year.
“Many bacteria build up an outer defence which is important for their survival and drug resistance. We have found a way to stop that happening.
"The number of superbugs are increasing at an unexpected rate. This research provides the platform for urgently-needed new generation drugs."
The discovery, reported in the journal Nature, could pave the way to a new generation of antibiotic drugs that work by bringing down the defensive wall.
Bugs such as MRSA (methicillin resistant Staphylococcus aureus) are becoming increasingly immune to "last resort" antibiotics.
If the trend continues the world may see a return to the pre-antibiotic era when even a trivial scratch could prove fatal.
At the heart of the breakthrough is the way "gram negative" bacterial cells transport the barrier's molecular "bricks" to the surface of the cell and form a wall.
"Gram-negative" bacteria, which include Escherichia coli (E. coli) and the bugs that cause gonorrhea, cholera and Legionnaire's disease, are especially resistant to antibiotics.
They can evolve a number of mechanisms to make them immune to drugs, including reducing the permeability of their outer membrane.
But if the membrane barrier falls, the bacteria die - whatever other defensive ploys they may have developed.
Haohao Dong, another member of the UAE team, said: "The really exciting thing about this research is that new drugs will specifically target the protective barrier around the bacteria, rather than the bacteria itself.
"Because new drugs will not need to enter the bacteria itself, we hope that the bacteria will not be able to develop drug resistance in future."
The science community and the Government said the research was a "welcome piece of news".
“We are facing a difficult era in terms of antibiotic resistance; the need for new efficacious drugs to treat infectious disease is clearly an important issue,” said Mark Fielder, Professor of Medical Microbiology at Kingston University and Hon Gen Sec of the Society for Applied Microbiology.
“The publication of data from the two groups is a welcome piece of news. Their findings give science an insight into some of the structures that are important in the development of a bacterial membrane.
“This could be of great importance as if we fully understand the workings and construction of structures that help bacteria function as effective entities we can hopefully then exploit weaknesses therein and kill the organism.”
Prof Brendan Wren, Professor of Microbial Pathogenesis, London School of Hygiene & Tropical Medicine, added: “The studies open new avenues to the design a novel class of antibiotics to disarm and kill pathogenic bacteria."
Deputy Chief Medical Officer John Watson said: “Antimicrobial resistance is a hugely important issue facing the world today.
“We welcome all efforts in this area and we will follow any further developments with interest.”
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