Antibiotics found to make bugs drug resistant

Researchers showed for the first time today that taking antibiotics can lead to bacterial drug resistance in a local community.

Researchers showed for the first time today that taking antibiotics can lead to bacterial drug resistance in a local community.

A two-year study in Wales revealed a clear link between antibiotic use and the ability of bacteria to resist certain drugs.

The research team, led by Dr John Magee, from the Public Health Laboratory Service, tested the antibiotic sensitivity of bugs in thousands of urine samples taken by GPs to diagnose urinary tract infections.

These results were matched against official data on the rates of prescribing broad spectrum penicillin antibiotics in north and south Wales.

In total about 30,000 isolates of bacteria from 190 GP surgeries serving about 1,200,000 patients were used in the study.

Urine samples were collected from the Bangor, Cardiff and Rhyl public health laboratories and the East Glamorgan, Prince Charles and Wrexham Maelor hospitals.

The researchers found that antibiotic use and rates of resistance varied between surgeries. But the more antibiotics a GP prescribed, the more resistance was seen in the local population.

There was often a "significant" association between prescribing an antibiotic and bacterial resistance to that particular drug.

In some cases one antibiotic led to bacteria developing resistance to another drug as well. Combined resistance to ampicillin and trimethoprim occurred in 21% of isolates.

The researchers said few of the isolated organisms were identified. Most were thought to be Escherichia coli (E.Coli), which contains transmittable genetic material that can make it resist both ampicillin and trimethorprim.

Dr Tony Howard, director of the Public Health Laboratory Service Wales, who helped in the research, said: "This study shows for the first time that there is a link between the antibiotics which a GP surgery prescribes, and antibiotic resistance patterns in the bugs isolated from the surgery's patients.

"We're certainly not saying that GPs should not be prescribing antiobiotics, but our work underlines the problems of increasing antibiotic resistance as a result of community prescribing as well as hospital prescribing. We need to manage all uses of antibiotics carefully, whether they are prescribed in hospitals, in GP surgeries, or in veterinary medicine."