Bacteriology in uncomplicated urinary tract infections in Norwegian general practice from 2001–2015

BACKGROUND: Uncomplicated urinary tract infections in women are common, and urine samples from these patients are not routinely cultured. Empirical treatment is based on knowledge of resistance patterns for common uropathogens. AIM: To evaluate the bacteriological findings and resistance patterns in urine samples from women with uncomplicated urinary tract infections, and to assess the relationship between antimicrobial use and resistance patterns from 2000–2015 in Norway. METHOD: Bacteriology and resistance patterns were compared in 184 urine cultures from 2001, 406 urine cultures from 2010–2011 and 259 urine cultures from 2013–2015. Antibiotic use data from 2000–2015 were obtained from national databases. RESULTS: Escherichia coli (E. coli) was the main bacterial agent in 80% of the cultures. Staphylococcus saprophyticus (Staph. saprophyticus) represented 6–17%. For E. coli, resistance to mecillinam showed some variation but remained below 9%. There was negligible resistance to nitrofurantoin. Resistance to trimethoprim seemed to stabilise over the last 5 years at around 20%. Amoxicillin resistance had some variations, but remained stable around 30%. There was a steady rise in total consumption of selected antibiotics commonly used to treat urinary tract infections for the period 2000–2015. CONCLUSION: Mecillinam and nitrofurantoin are both excellent first choices for empirical treatment of uncomplicated urinary tract infections. This study suggests that increasing resistance to trimethoprim challenges the rationale for its use as a first-line agent.