Short-term antibiotic exposure affected the type and resistance of uropathogens similar to long-term antibiotic prophylaxis in children hospitalised for urinary tract infections

Aim: We investigated the impact of any antibiotic exposure on unusual and resistant pathogens in children with a urinary tract infection (UTI).

Methods: This was a retrospective cohort study of 695 children (54% female) hospitalised with 711 UTI episodes at Heraklion University Hospital, Greece, from January 2007 to December 2017. Three groups were studied: no previous antibiotic exposure, ongoing prophylaxis and short-term exposure to antibiotics in the last six months.

Results: The median age at hospitalisation was 0.8 years (range 25 days to 15.9 years). Previous short-term exposure and prophylaxis were important determinants of non-Escherichia coli (E. coli) (OR 2.05, 95% CI 1.25-3.36, P = .0017 and OR 3.84, 95% CI 2.32-6.34, P < .0001, respectively) and extended-spectrum beta-lactamase-positive uropathogens (OR 2.43, 95% CI 1.36-4.32, P = .0025 and OR 2.63, 95% CI 1.31-5.33, P = .0070, respectively). Short-term antibiotics in the last 30 days or intravenous antibiotics were mostly associated with non-E. coli pathogens (OR 6.71 and OR 2.55, respectively). The most important determinants of E. coli resistance were short-term antibiotics for ampicillin (OR 2.58) and prophylaxis for cotrimoxazole (OR 2.64).

Conclusion: Recent short-term exposure to antibiotics and ongoing prophylaxis both had a significant impact on the type and resistance of uropathogens.