Scientists have discovered a new and highly effective weapon against deadly superbugs like the MRSA sweeping through Britain’s dirty hospital wards – green French muck.
The dramatic antibiotic success of agricur, a clay made from ancient volcanic ash found near the Massif Central, marks it out as a potential rival to penicillin, the wonder drug of the 20th century. In experiments, the clay killed up to 99 per cent of superbug colonies within 24 hours. Control samples of MRSA (methicillin-resistant Staphylococcus aureus) grew 45-fold in the same period.
The clay has a similar effect on other deadly bacteria tested, including salmonella, E. coli, and a flesh-eating disease called buruli, a relative of leprosy which disfigures children across central and western Africa. It has been classed as "an emerging public health threat" by the World Health Organization (WHO).
MRSA is also a growing concern. Since the early 1990s, deaths in the UK have risen sharply from fewer than 100 annually to more than 1,600 in 2005. The Governmentrecently announced new measures to deep clean all hospital wards in an attempt to cut the number of infections.
Many other bacteria have also developed resistance to medicine’s arsenal of antibiotics, largely because patients stop using prescribed drugs when they begin to feel better rather than finishing their course of treatment, allowing the hardiest bugs to survive and spread. Some bacteria are now resistant to a spectrum of drugs. As a result, the developed world is starting to see the return of diseases, such as tuberculosis, that had been all but wiped out a few decades ago.
Scientists have been searching for new antibiotics to replace penicillin, methicillin and their relatives but until now have had only limited success. Agricur’s discovery could lead to a whole class of antibiotics to which bugs such as MRSA have no resistance, according to scientists.
Dr Lynda Williams and Dr Shelley Haydel of Arizona State University will present the results of their research on agricur and other clays to the Geological Society of America’s annual meeting in Denver tomorrow.
"We have found several antibacterial clays," said Dr Williams, a mineralogist who is trying to work out the chemicals that make them special. "We have multiple working hypotheses. Our primary hypothesis is that the clay minerals transfer elements, not yet identified, to the bacteria that impede their metabolic function.
“It is entirely possible that it is not one single element that is toxic to the bacteria, but a combination of elements and chemical conditions that attack the bacteria from different angles so as to overwhelm their defence systems,” she said.