Antibacterial Susceptibilities of Escherichia coli from Community-Acquired Urinary Tract Infections in the Faroe Islands, Associations with Antibacterial Sales, and Comparison with Iceland and Denmark

Abstract

Currently, data on Escherichia coli antibacterial susceptibilities in the Faroe Islands are lacking. The aim was to investigate the antibacterial susceptibilities of E. coli from patients with community-acquired urinary tract infections in the Faroe Islands, correlate with antibacterial sales, and compare with Iceland and Denmark. From 2009 to 2010 and in 2012, 12 general practitioners from the Faroe Islands were recruited to provide urine samples from patients. Antibacterial susceptibilities were determined by disc diffusion testing according to the Clinical and Laboratory Standards Institute methods and criteria. Logistic regression (quasibinomial) of the antibacterial resistance proportions versus mean sales during the period of 2008-2011 was used to determine association. Nonsusceptibility to at least 1 of the 14 antibacterial drugs investigated was found in 54% of the E. coli isolates and was most common to ampicillin (46%), followed by sulfamethoxazole (39%), trimethoprim (27%), trimethoprim/sulfamethoxazole (27%), and <10% to the remaining 10 antibiotics. The resistance prevalence did not change significantly with time. From logistic regression modeling, we find significant associations between antibacterial mean sales and antibacterial resistances. For the resistances in the Faroe Islands compared with data from Denmark and Iceland, we infer two groups of resistances indicating different responses-one steep and one gradual-to antibacterial sales. For these two groups, we find β1 = 4.77 (Std. Error = 0.624, p-value = 0.002) and β1 = 0.26 (Std. Error = 0.020, p-value = 4e-7) for the steep and gradual groups, respectively. This knowledge can potentially be used to predict and control the future increase in E. coli resistance with antibacterial sales.