Rates of antimicrobial resistance (AMR) in urinary Escherichia coli isolates are rising in both hospital and community settings in Australia, researchers reported last week in the Journal of Global Antimicrobial Resistance.
For the study, Australian researchers analyzed 108,262 urinary E coli isolates collected from a public hospital-based laboratory (34, 103 isolates) and a private community-based laboratory (74,159 isolates) in the Illawarra Shoelhaven region in New South Wales from 2007 to 2019. They tested the isolates for susceptibility to ampicillin, amoxicillin-clavulanate, cephalexin, norfloxacin, and trimethoprim, and used linear regression analysis to identify any significant changes in AMR rates over time. Up to 80% of all urinary tract infections (UTIs) are caused by E coli.
For all antibiotics other than ampicillin, the results of the linear regression analysis showed the AMR trends increased significantly over the 12-year period for both laboratory settings, with AMR rates consistently higher in the public hospital-based setting. But the study authors note that the volume of resistant isolates for commonly used antibiotics like trimethoprim and ampicillin were much higher in the community-based setting, where the vast majority of UTI treatments occur.
"There is a need for localised and regional surveillance of AMR," they wrote. Given that the largest volume is in the outpatient setting, and >90% of all antibiotic prescriptions are issued in primary care, interventions that incorporate the outpatient setting are critical to addressing AMR."