THE battle against hospital superbugs has suffered a serious setback after scientists discovered one of the most deadly bacteria has developed resistance to the main antibiotic used to kill it.
Recent tests on the stomach bug Clostridium difficile – 'C diff' – suggest a new strain has mutated which is more likely to survive treatment with metronidazole, currently the "front line" antibiotic.
That leaves only one antibiotic, vancomycin, available to treat the mutated superbug. Doctors are reluctant to increase use of vancomycin because that increases the risk of C diff becoming resistant to the last line of defence.
Health officials last night warned doctors to be vigilant for any signs that patients were not responding to treatment and could be infected with the new strain. Patients' groups described the development as "very disturbing" and called for urgent action to improve hygiene in hospitals.
The revelation is contained in a new report by public health officials at the Health Protection Agency Centre for Infections. Routine tests carried out on samples taken from C diff patients showed that a common strain of the superbug had survived, despite being treated with metronidazole.
Further tests suggest that C diff has fought back against the antibiotic and mutated to develop a resistance to the drug. This new strain is already thought to have spread between patients.
C diff is linked to poor cleanliness in hospital wards and has become a major concern across the UK. Last year there were over 6,000 cases in Scotland.
A spokeswoman for the Health Protection Agency Centre for Infections said: "As a result of ongoing studies looking at potential antibiotic resistance to C difficile, we have seen evidence of a reduced susceptibility to metronidazole.
"However, we are still recommending this antibiotic as the first treatment for mild to moderate cases of C difficile.
"Doctors need to be alert for any evidence of treatment failure linked to metronidazole resistance to ensure the situation is being carefully monitored."
In the 6,035 cases recorded across Scotland last year the bug was the main cause of death of 164 people and a contributing factor in the deaths of a further 253 people.
C diff usually strikes patients who are on antibiotics for other illnesses. The antibiotics kill healthy gut bacteria, making the body more susceptible to the infection, which causes severe diarrhoea. Once someone has the infection, spores from their diarrhoea can spread and infect other patients. The spores can survive for a long time in the environment and spread on the hands of health staff who touch contaminated items.
The samples were taken from patients in the Leeds area of England. But because of the highly-infectious nature of C diff the mutated strain could spread quickly across the country.
The C diff strain in question is the 001 strain, the second most common in the UK, thought to affect around 20% of patients. However, it is less deadly than the 'hypervirulent' 027 strain which is still relatively rare in this country. The scientists found almost one-quarter of samples of this strain, 21 out of 88 cases, had "reduced susceptibility" to the antibiotic.
Margaret Watt, chairwoman of the Scotland Patients' Association, said:
"We need to bring back ward matrons who are responsible for ward cleanliness and staff who are found not washing their hands should be given a written warning."
Professor Nigel Minton, from the Centre for Healthcare Associated Infections, said: "It's just natural selection at the end of the day. If you subject bacteria to antibiotics they will find a way around it.
The UK has the worst C diff infection rates in the world so... we need to improve."
There are currently few hopes for a new treatment for C difficile. So far no alternative drug has proved effective. Meanwhile other measures are being developed including cutting down the number of prescriptions of drugs that are known to damage the healthy balance of the gut.
Health Secretary Nicola Sturgeon said: "We expect all health boards to have robust policies in place to help manage C diff. These should include monitoring of compliance with cleaning standards, infection control precautions, prudent prescribing of antibiotics and rapid, accurate diagnosis of cases."
She added that 54m earmarked to
fight hospital acquired infection would drive down rates of C diff.