title: Long-term resistance trends of uropathogens and association with antimicrobial prophylaxis.
abstract: BACKGROUND
  The aim of this study was to identify long-term resistance trends of uropathogens and determine the effect of prophylaxis in a pediatric patient population.
  
  
  METHODS
  A total of 638 uropathogens were isolated from urine samples collected from children hospitalized for urinary tract infection during the 12-year study period (1997-2008) and analyzed.
  
  
  RESULTS
  The most frequent uropathogen identified was Escherichia coli (69 %), followed by Klebsiella spp. (9.7 %), Pseudomonas aeruginosa (6.7 %), Enterococcus spp. (5.6 %), and Proteus spp. (4.4 %). High resistance rates were observed for common agents used for empiric treatment, such as amoxicillin, cotrimoxazole, and ceftriaxone. Resistance increased over time for nitrofurantoin, ceftriaxone, and piperacilin-tazobactam (chi-square for trend p < 0.0002, p < 0.0034 and p < 0.014, respectively) and decreased for cefuroxime (p < 0.016) and gentamicin (p < 0.014). The use of prophylaxis was related to an increased proportion of non-E. coli pathogens (46.9 vs. 26.9 %; odds ratio 2.4, 95 % confidence interval 1.61-3.55; p < 0.0001), as well as to increased resistance of non-E. coli pathogens, and was a major risk factor associated with resistance to amoxiclav (p < 0.005), cotrimoxazole (p < 0.0001), cefuroxime (p < 0.0001), ceftriaxone (p < 0.0001), gentamicin (p < 0.0001), and nitrofurantoin (p < 0.0001).
  
  
  CONCLUSIONS
  Our findings point to considerable changes in the long-term resistance patterns of uropathogens and an association of prophylaxis with resistance. Our results suggest the need for continuous surveillance, re-evaluation of empiric regimens and further assessment of the role of prophylaxis in the treatment of urinary tract infection.
authors.affiliation: Department of Paediatrics, University Hospital of Heraklion, Crete, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Bitsori
authors.forename: Sofia
authors.initials: S
authors.lastname: Maraki
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Galanakis
mesh_terms: D000293:Adolescent; D019072:Antibiotic Prophylaxis; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004352:Drug Resistance, Microbial; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008826:Microbial Sensitivity Tests; D012008:Recurrence; D012189:Retrospective Studies; D014552:Urinary Tract Infections / Q000453:epidemiology / Q000382:microbiology* / Q000517:prevention & control*