title: Colonisation and infection due to Enterobacteriaceae producing plasmid-mediated AmpC β-lactamases.
abstract: OBJECTIVE
  To investigate the epidemiology and clinical features of infections caused by Enterobacteria producing plasmid-mediated AmpC β-lactamases (pAmpC), which are emerging as a cause of resistance to extended-spectrum cephalosporins.
  
  
  METHODS
  A prospective multicentre cohort of patients with infection/colonisation due to pAmpC-producing Enterobacteriaceae was performed in 7 Spanish hospitals from February throughout July 2009. pAmpCs were characterised by PCR and sequencing.
  
  
  RESULTS
  140 patients were included; organisms isolated were Escherichia coli (n = 100), Proteus mirabilis (n = 20), Klebsiella pneumoniae (n = 17), and others (n = 3). Overall, 90% had a chronic underlying condition. The acquisition was nosocomial in 43%, healthcare-associated in 41% (14% of those were nursing home residents), and community in 16%. Only 5% of patients had no predisposing feature for infection with multidrug-resistant bacteria. Nineteen percent of patients were bacteraemic. Inappropriate empirical therapy was administered to 81% of bacteraemic patients, who had a crude mortality rate of 48%. The most frequent enzyme was CMY-2 (70%, predominantly in E. coli and P. mirabilis) followed by DHA-1 (19%, predominantly in K. pneumoniae).
  
  
  CONCLUSIONS
  pAmpC-producing Enterobacteriaceae caused nosocomial, healthcare-associated and community infections mainly in predisposed patients. Invasive infections were associated with high mortality which might be partly related to inappropriate empirical therapy.
authors.affiliation: Unidad Clínica de Enfermedades Infecciosas y Microbiología, Hospital Universitario Virgen Macarena, Avda Dr Fedriani 3, 41009 Sevilla, Spain. jesusrb@us.es
authors.forename: Jesús
authors.initials: J
authors.lastname: Rodríguez-Baño
authors.forename: Elisenda
authors.initials: E
authors.lastname: Miró
authors.forename: Macarena
authors.initials: M
authors.lastname: Villar
authors.forename: Alicia
authors.initials: A
authors.lastname: Coelho
authors.forename: Mónica
authors.initials: M
authors.lastname: Gozalo
authors.forename: Nuria
authors.initials: N
authors.lastname: Borrell
authors.forename: Germán
authors.initials: G
authors.lastname: Bou
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Conejo
authors.forename: Virginia
authors.initials: V
authors.lastname: Pomar
authors.forename: Belén
authors.initials: B
authors.lastname: Aracil
authors.forename: Nieves
authors.initials: N
authors.lastname: Larrosa
authors.forename: Jesús
authors.initials: J
authors.lastname: Agüero
authors.forename: Antonio
authors.initials: A
authors.lastname: Oliver
authors.forename: Ana
authors.initials: A
authors.lastname: Fernández
authors.forename: Jesús
authors.initials: J
authors.lastname: Oteo
authors.forename: Alvaro
authors.initials: A
authors.lastname: Pascual
authors.forename: Ferran
authors.initials: F
authors.lastname: Navarro
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D002511:Cephalosporins / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003428:Cross Infection / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity*; D004756:Enterobacteriaceae Infections / Q000453:epidemiology / Q000382:microbiology* / Q000401:mortality; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010957:Plasmids; D011513:Proteus mirabilis / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity; D013030:Spain; D055815:Young Adult; D018440:beta-Lactam Resistance / Q000235:genetics; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002511:Cephalosporins; C048795:AmpC beta-lactamases; D001618:beta-Lactamases