High resistance rates to 2^nd and 3^rd generation cephalosporins, ciprofloxacin and gentamicin of the uropathogens isolated in young infants hospitalized with first urinary tract infection

Aims: To describe the characteristics of febrile UTI in hospitalized infants and to characterize the uropathogens distribution and antimicrobial resistance rates. Methods: Retrospective study performed during 2010-2013, including all infants <3 months of age admitted with the diagnosis of UTI proven by urine culture obtained by bladder catheterization. Results: 117 infants with 1st UTI episode were enrolled. There were 18 (15.39%), 57 (48.72%) and 42 (35.9%) infants aged 0-1, 1-2 and 2-3 months; 5.99% had previous renal anomalies. Fever >38°C at admission was recorded in 33 (28.2%). Leukocytosis, leukopenia and neutropenia were recorded in 20 (17.1%), 2 (1.7%) and 5 (4.3%) patients, respectively. Escherichia coli, Klebsiella spp., Enterococcus spp., Morganella morganii, Proteus spp. and Enterobacter spp. were the most common pathogens (53.3%, 10.6%, 5.2%, 5.2%, 4.5%, and 3.9% of all episodes, respectively). No differences were recorded between E. coli or Klebsiella spp.-UTI cases recorded in male vs. female patients and between the 3 age subgroups. The antibiotic resistance rates of E. coli were 61.8%, 57.4%, 50% and 45.6% for ceftriaxone, cefuroxime, gentamicin and ciprofloxacin, respectively. The antibiotic resistance rates of Klebsiella spp. were 82.9%, 80%, 54.3% and 54.3% for ceftriaxone, cefuroxime, gentamicin and ciprofloxacin, respectively. 80.9% and 42.9% of the E. coli and Klebsiella spp. isolates were ESBL-producers. The resistance rates of the 2 major pathogens to piperacillin/tazobactam, meropenem, nalidixic acid, chloramphenicol and colistin were low. Conclusion: The high resistance rates to major antibiotic classes of uropathogens isolated in hospitalized infants with UTI require close periodically monitoring and may require modification of empirical antibiotic therapies in use for these patients.