Resistance Patterns from Urine Cultures in Children Aged 0 to 6 Years: Implications for Empirical Antibiotic Choice.

Purpose Urinary tract infection (UTI) is a frequent disorder of childhood, caused mainly by Gram negative Enterobacterales. The aim of this study is to evaluate etiology and antimicrobial susceptibility patterns of bacterial isolates in urine cultures of children under the age of 6 and to analyze the relationship between previous hospitalization or antibiotic prescriptions and antimicrobial resistance rates. Patients and methods A retrospective study on positive urine cultures from 13 public laboratories in Tuscany, Italy was conducted. Data were obtained by reviewing records of the "Microbiological and Antibiotic-Resistance Surveillance System" (SMART) in Tuscany, Italy. A total of 2944 positive urine cultures were collected from 2445 children. Results Escherichia coli represented the majority of isolates (54,2%), followed by Enterococcus faecalis (12,3%), Proteus mirabilis (10,3%) and Klebsiella pneumoniae (6,6%). Isolated uropathogens showed high resistance rates to amoxicillin-clavulanate (>25%), particularly in children under one year of age or hospitalized within the 12 months before the sample collection. High susceptibility rates were reported of aminoglycosides, cephalosporins and quinolones (>90%). Previous antibiotic prescriptions by general pediatricians did not increase resistance rates. Conclusion Our results show a rate of amoxicillin-clavulanate resistance of 25%. Higher resistance rates were reported in children under one year of age and with previous hospitalization. Hence, amoxicillin-clavulanate should be used carefully in young children and those with severe symptoms.