title: Progressive increase of resistance in Enterobacteriaceae urinary isolates from kidney transplant recipients over the past decade: narrowing of the therapeutic options.
abstract: BACKGROUND
  Antibiotic resistance is an emerging phenomenon in kidney transplantation (KT).
  
  
  METHODS
  We compared species distribution and antimicrobial susceptibility patterns in 1052 isolates from urine cultures obtained in 2 different cohorts of kidney transplant recipients in a single center (Cohort A: 189 patients undergoing KT between January 2002 and December 2004 [336 isolates]; Cohort B: 115 patients undergoing KT between January 2011 and December 2013 [716 isolates]).
  
  
  RESULTS
  Asymptomatic bacteriuria accounted for most of the isolates (86.9% in Cohort A and 92.3% in Cohort B). Klebsiella pneumoniae (9.5% vs. 15.6%), Pseudomonas aeruginosa (1.8% vs. 7.9%), and Enterobacter cloacae (0.6% vs. 3.1%) were significantly more common in Cohort B. The isolation of K. pneumoniae in Cohort B was associated with the occurrence of acute pyelonephritis (9.8% of all K. pneumoniae isolates vs. 2.8% of the remaining uropathogens; P = 0.001). Non-susceptibility rates among Enterobacteriaceae in Cohort B were higher for every class of antibiotics (P ≤ 0.003) with the exception of fosfomycin. Compared to Cohort A, significant increases were seen in isolates from Cohort B for multidrug-resistant (MDR) (43.9% vs. 67.8%, respectively; P = 0.001), extended-spectrum beta-lactamase (ESBL)-producing (6.6% vs. 26.1%; P = 0.001), and carbapenemase-producing Enterobacteriaceae strains (0.0% vs. 5.0%; P = 0.001). Such differences were mostly attributable to K. pneumoniae (as 54.5% and 13.4% of isolates in Cohort B were ESBL-producing and carbapenemase-producing, respectively). MDR isolates were responsible for 69.1% of episodes of symptomatic urinary tract infection in Cohort B.
  
  
  CONCLUSIONS
  The increase in resistance rates among Enterobacteriaceae uropathogens is significant and may have an effect on KT programs.
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Origüen
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Fernández-Ruiz
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: F
authors.initials: F
authors.lastname: López-Medrano
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: T
authors.initials: T
authors.lastname: Ruiz-Merlo
authors.affiliation: Department of Nephrology, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: González
authors.affiliation: Department of Nephrology, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Morales
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Fiorante
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: San-Juan
authors.affiliation: Department of Microbiology, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Villa
authors.affiliation: Department of Microbiology, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: M Á
authors.initials: MÁ
authors.lastname: Orellana
authors.affiliation: Department of Nephrology, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Andrés
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Aguado
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D058345:Asymptomatic Infections; D001426:Bacterial Proteins / Q000378:metabolism; D024881:Drug Resistance, Bacterial; D016972:Enterobacter cloacae / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000188:drug therapy / Q000382:microbiology* / Q000652:urine; D005260:Female; D005578:Fosfomycin / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects*; D007710:Klebsiella Infections / Q000382:microbiology / Q000652:urine; D007711:Klebsiella pneumoniae / Q000302:isolation & purification; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011552:Pseudomonas Infections / Q000382:microbiology / Q000652:urine; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D014552:Urinary Tract Infections / Q000188:drug therapy / Q000382:microbiology* / Q000652:urine; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D005578:Fosfomycin; D001618:beta-Lactamases; C063912:carbapenemase
keywords: antibiotic resistance; gram-negative bacilli; kidney transplantation; urine culture; uropathogen