title: Urinary Tract Infections in Kidney Transplant Patients Due to Escherichia coli and Klebsiella pneumoniae-Producing Extended-Spectrum β-Lactamases: Risk Factors and Molecular Epidemiology.
abstract: Urinary tract infection (UTI) is a common complication after kidney transplantation, often associated to graft loss and increased healthcare costs. Kidney transplant patients (KTPs) are particularly susceptible to infection by Enterobacteriaceae-producing extended-spectrum β-lactamases (ESBLs). A retrospective case-control study was conducted to identify independent risk factors for ESBL-producing Escherichia coli and Klebsiella pneumoniae in non-hospitalized KTPs with UTI. Forty-nine patients suffering from UTI by ESBL-producing bacteria (ESBL-P) as case group and the same number of patients with UTI by ESBL negative (ESBL-N) as control-group were compared. Clinical data, renal function parameters during UTI episodes, UTI recurrence and relapsing rate, as well as risk factors for recurrence, molecular characterization of isolates and the respective antimicrobial susceptibility profile were evaluated. Diabetes mellitus (p <0.007), previous antibiotic prophylaxis (p=0.017) or therapy (p<0.001), previous UTI (p=0.01), relapsing infection (p=0.019) and patients with delayed graft function after transplant (p=0.001) represented risk factors for infection by ESBL positive Enterobacteriaceae in KTPs. Interestingly, the period of time between data of transplantation and data of UTI was shorter in case of ESBL-P case-group (28.8 months) compared with ESBL-N control-group (50.9 months). ESBL-producing bacteria exhibited higher resistance to fluoroquinolones (p=0.002), trimethoprim-sulfamethoxazole (p<0.001) and gentamicin (p<0.001). Molecular analysis showed that blaCTX-M was the most common ESBL encoding gene (65.3%), although in 55.1% of the cases more than one ESBL gene was found. In 29.4% of K. pneumoniae isolates, three bla-genes (blaCTX-M-blaTEM-blaSHV) were simultaneously detected. Low estimated glomerular filtration rate (p=0.009) was found to be risk factor for UTI recurrence. Over 60% of recurrent UTI episodes were caused by genetically similar strains. UTI by ESBL-producing Enterobacteriaceae in KTPs represent an important clinical challenge regarding not only hospitalized patients but also concerning outpatients.
authors.affiliation: Department of Microbiology, Faculty of Medicine, University of Porto, Porto, Portugal; Clinical Pathology Department, Hospital São João, Porto, Portugal.
authors.forename: Maria José
authors.initials: MJ
authors.lastname: Espinar
authors.affiliation: Department of Microbiology, Faculty of Medicine, University of Porto, Porto, Portugal; CINTESIS-Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Porto, Portugal.
authors.forename: Isabel M
authors.initials: IM
authors.lastname: Miranda
authors.affiliation: Department of Microbiology, Faculty of Medicine, University of Porto, Porto, Portugal; CINTESIS-Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Porto, Portugal.
authors.forename: Sofia
authors.initials: S
authors.lastname: Costa-de-Oliveira
authors.affiliation: Department of Microbiology, Faculty of Medicine, University of Porto, Porto, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Rocha
authors.affiliation: Department of Microbiology, Faculty of Medicine, University of Porto, Porto, Portugal; Clinical Pathology Department, Hospital São João, Porto, Portugal.
authors.forename: Acácio G
authors.initials: AG
authors.lastname: Rodrigues
authors.affiliation: Department of Microbiology, Faculty of Medicine, University of Porto, Porto, Portugal; Clinical Pathology Department, Hospital São João, Porto, Portugal; CINTESIS-Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Porto, Portugal.
authors.forename: Cidália
authors.initials: C
authors.lastname: Pina-Vaz
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D004926:Escherichia coli / Q000201:enzymology; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000209:etiology / Q000382:microbiology*; D005260:Female; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects*; D007710:Klebsiella Infections / Q000188:drug therapy / Q000209:etiology / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000201:enzymology; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D017720:Molecular Epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000627:therapeutic use; D014552:Urinary Tract Infections / Q000188:drug therapy / Q000209:etiology / Q000382:microbiology*; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D001618:beta-Lactamases