title: Bloodstream infections caused by Escherichia coli producing AmpC β-lactamases: epidemiology and clinical features.
abstract: The aim of the study was to investigate the epidemiology and clinical features of bloodstream infections due to Escherichia coli producing AmpC β-lactamases (AmpC-Ec-BSI). In a multi-centre case-control study, all third-generation-cephalosporin-resistant Escherichia coli BSI (3GC-Ec-BSI) isolates were analysed. Acquired blaAmpC(blaac-AmpC) detection was done by polymerase chain reaction (PCR) and sequencing. Chromosomal blaAmpC(blac-AmpC) expression was quantified by real-time PCR. Cases were patients with AmpC-Ec-BSI. Controls were patients with cephalosporin-susceptible E. coli BSI, matched 1:1 by sex and age. Demographics, comorbidities, intrinsic and extrinsic risk factors for antimicrobial resistance, clinical presentation and outcomes were investigated. Among 841 E. coli BSI, 17 were caused by AmpC-Ec (2 %). Eleven isolates (58.8 %) had blaac-AmpCand six were blac-AmpCoverproducers. The mean age of cases was 66.2 years and 71 % were men. Cases were more frequently healthcare-related (82 vs. 52 % controls, p < 0.05) and presented more intrinsic and extrinsic risk factors. At least one risk factor was present in 94.1 % of cases vs. 41.7 % of controls (p = 0.002). Severity and length of stay (LOS) were higher among cases (mean Pitt Score 2.6 vs. 0.38 in controls, p = 0.03; LOS 17.5 days vs. 6 in controls, p = 0.02). Inappropriate empirical therapy (IET) was administered to 70.6 % of cases and 23.5 % of controls (p < 0.003). No differences were found in terms of cure rate at the 14th day and mortality. Bloodstream infections due to AmpC-Ec (mostly plasmid-mediated) are infrequent in our area. AmpC-Ec-BSI affects mainly patients with intrinsic risk factors and those with previous antibiotic exposure. A high proportion received IET.
authors.affiliation: Infectious Disease Unit, Service of Internal Medicine, Hospital Universitari Mútua de Terrassa, Plaza Dr. Robert 5, 08021, Terrassa, Barcelona, Spain. vanesapascual@hotmail.com.
authors.forename: V
authors.identifier: http://orcid.org/0000-0002-2485-0822
authors.initials: V
authors.lastname: Pascual
authors.affiliation: Hospital de la Santa Creu i Sant Pau and Institut d'Investigació Biomèdica Sant Pau (IIB Sant Pau), Barcelona, Spain.|Universitat Autònoma de Barcelona, Barcelona, Spain.|Red Española de Investigación en Patología Infecciosa (REIPI), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Alonso
authors.affiliation: Catlab, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Simó
authors.affiliation: Hospital de la Santa Creu i Sant Pau and Institut d'Investigació Biomèdica Sant Pau (IIB Sant Pau), Barcelona, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Ortiz
authors.affiliation: Consorci Sanitari de Terrassa, Barcelona, Spain.
authors.forename: M C
authors.initials: MC
authors.lastname: Garcia
authors.affiliation: Catlab, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Xercavins
authors.affiliation: Hospital de la Santa Creu i Sant Pau and Institut d'Investigació Biomèdica Sant Pau (IIB Sant Pau), Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Rivera
authors.affiliation: Catlab, Barcelona, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Morera
authors.affiliation: Hospital de la Santa Creu i Sant Pau and Institut d'Investigació Biomèdica Sant Pau (IIB Sant Pau), Barcelona, Spain.|Red Española de Investigación en Patología Infecciosa (REIPI), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Miró
authors.affiliation: Consorci Sanitari de Terrassa, Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Espejo
authors.affiliation: Hospital de la Santa Creu i Sant Pau and Institut d'Investigació Biomèdica Sant Pau (IIB Sant Pau), Barcelona, Spain.|Universitat Autònoma de Barcelona, Barcelona, Spain.|Red Española de Investigación en Patología Infecciosa (REIPI), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Navarro
authors.affiliation: Hospital de la Santa Creu i Sant Pau and Institut d'Investigació Biomèdica Sant Pau (IIB Sant Pau), Barcelona, Spain.|Universitat Autònoma de Barcelona, Barcelona, Spain.|Red Española de Investigación en Patología Infecciosa (REIPI), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Gurguí
authors.affiliation: Catlab, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Pérez
authors.affiliation: Infectious Disease Unit, Service of Internal Medicine, Hospital Universitari Mútua de Terrassa, Plaza Dr. Robert 5, 08021, Terrassa, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Rodríguez-Carballeira
authors.affiliation: Infectious Disease Unit, Service of Internal Medicine, Hospital Universitari Mútua de Terrassa, Plaza Dr. Robert 5, 08021, Terrassa, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Garau
authors.affiliation: Infectious Disease Unit, Service of Internal Medicine, Hospital Universitari Mútua de Terrassa, Plaza Dr. Robert 5, 08021, Terrassa, Barcelona, Spain.|Universitat Internacional de Catalunya, Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Calbo
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology / Q000473:pathology*; D001426:Bacterial Proteins / Q000378:metabolism*; D016022:Case-Control Studies; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology / Q000473:pathology*; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012307:Risk Factors; D017422:Sequence Analysis, DNA; D012720:Severity of Illness Index; D016896:Treatment Outcome; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C048795:AmpC beta-lactamases; D001618:beta-Lactamases