[Antibiotic resistance of E coli isolated from healthy persons]

Abstract

Introduction: The aim of the study was to determine the antibiotic susceptibility of E. coli isolates in stools from healthy Danes.

Methods: Sixty-nine persons from Copenhagen participated in the study. Three faecal samples from each participant were examined by culture for each of three periods. E. coli was isolated selectively and tested for sensitivity against sulfamethizole, trimethoprim, the combination of sulfamethizole and trimethoprim, ampicillin, mecillinam, cefuroxime, nitrofurantoin, and ciprofloxacin.

Results: Altogether, 184 strains of E. coli were isolated from 66 of the 69 persons. Fifty-eight (31.5%) of the strains isolated from 30 persons (43.5%) were resistant to sulfamethizole, 32 (17.4%) strains isolated from 18 persons (26.1%) were resistant to trimethoprim, 31 (16.8%) strains isolated from 17 persons (24.6%) were resistant to trimethoprim + sulfamethizole, 57 (31%) strains from 31 persons (44.9%) were resistant to ampicillin, 29 (15.8%) of the strains from 24 persons (34.8%) were resistant to nitrofurantoin, two (1.1%) strains from two persons (2.9%) were resistant to cefuroxime, whereas none of the strains was resistant to mecillinam and ciprofloxacin.

Discussion: The high prevalence of resistance to sulfamethizole, ampicillin, trimethoprim, and nitrofurantoin is surprising, as none of the persons had been treated with antibiotics, but it may reflect the widespread use of antibiotics in animals for food production. The consequences of the results for empiric antibiotic treatment of, for instance, urinary tract infection are discussed.