Superbug strains have spread to nursing homes and into the community

Nov 27 2007

Hospital superbugs that can break down antibiotics are so widespread throughout Europe that doctors increasingly have to use the few remaining drugs that they reserve for emergencies.

Now these hospital superbug strains have spread to nursing homes and into the community in Ireland, raising fears of wider antibiotic resistance, scientists heard today (Wednesday 28 November 2007) at the Federation of Infection Societies Conference 2007 at the University of Cardiff, UK, which runs from 28-30 November 2007.

Doctors collected 732 samples from 22 Irish hospitals over the last ten years and found that 61% of them, 448 samples, tested positive for bacteria that can produce an enzyme that destroys a whole family of common antibiotics including penicillins and cephalosporins.

“The ability to make these enzymes – called extended spectrum beta-lactamases (ESBLs) –spreads very easily between different types of bacteria”, says Dr Dearbhaile Morris from the National University of Ireland Galway, Ireland. “It lets them break down many different penicillins and cephalosporins. So the genetic ability to resist very important antibiotics often spreads with the ability to make ESBLs, and that means that doctors increasingly have to use antibiotics which in the past were held back for exceptional cases”.

During the years 2003 and 2004 a severe outbreak of cystitis, an infection of the bladder, was caused in the UK by E. coli bacteria that could produce a particular type of extended spectrum beta-lactamase enzyme. The Irish research team were trying to find out how common similar strains of antibiotic resistant bacteria are in Ireland.

“Our results showed that ESBL producing bacteria, especially of the type which caused the bladder infections in the UK outbreak, are now common in Ireland as well as in other countries in Europe. We also showed that they are not just found in hospitals but also in nursing homes and in the community”, says Dr Morris.

Although cystitis is not life threatening, it is the most common form of urinary tract infection, and the economic consequences of failing to treat an outbreak quickly and properly are considerable. The patients may get no benefit at all from treatment with common antibiotics, which means that they will feel sick for longer, miss more work or household duties, and will probably have to return to their doctor for more time consuming tests and different antibiotics, increasing the costs for the health care system. In severe infections patients may suffer serious complications if the first antibiotic given to them does not work.

“It is very important to track the spread of antibiotic resistant bacteria so that doctors have the information to make a good choice of antibiotic in the early stages of infection before the lab has had time to find out exactly which type of bacteria is causing the infection and which antibiotic they can depend on to work” says Dr Dearbhaile Morris. “ESBL producing bacteria can break down several of the most commonly used antibiotics in clinical practice today so it is important that we know how common they are”.

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