A STUDY AT Tallaght Hospital, which included more than 42,000 samples, found that antimicrobial resistance in E.coli urinary tract infections has risen in recent years.
The findings, published recently in the British Journal of Urology International, found trends of increasing antimicrobial resistance between 1999 and 2009.
E.coli is the most common bacterium that causes urinary tract infections, or UTIs, accounting for up to 80 per cent in the community and up to 60 per cent in the hospital, explained lead author Dr Ivor Cullen, who is now a senior specialist registrar in urological surgery in St James’s Hospital, but worked at Tallaght when the study on the E.coli-positive isolates was carried out.
“We separated the urine samples into three groups – samples from hospital inpatients in general, samples from urology patients and samples from community UTIs,” he said.
“As expected, the resistance rates to commonly used antibiotics are highest for hospital inpatients, as these patients have often had recent surgery or intervention and often have had previous exposure to antibiotics.”
The study suggests changes are needed in some first-line antibiotic therapies, and the findings particularly highlighted increasing resistance to the antibiotic gentamicin, noted Cullen.
“Overall gentamicin resistance rate was 3.4 per cent and is climbing at a rate of 0.7 per cent per year,” he said. “This is particularly concerning, as this agent would be a first line choice for unwell hospital patients with UTI.”
Cullen, whose co-authors on the paper included John Thornhill and Ronald Grainger, described how the study is the largest of its kind performed to date and it should help to promote evidence-based prescribing.
“Ineffective treatment of UTI with inappropriate antibiotic agents has serious repercussions. The patients may be exposed to multiple courses of antibiotics – as the first choices are ineffective – and it also leads to further evolution of resistant strains within the community and the hospital. There is an obvious monetary cost to ineffective prescribing,” he said.
