title: Detection and characterization of multidrug-resistant enterobacteria bearing aminoglycoside-modifying gene in a university hospital at Rio de Janeiro, Brazil, along three decades.
abstract: BACKGROUND
  Multidrug-resistant Enterobacteriaceae, particularly those resistant to gentamicin, have become one of the most important causes of nosocomial infections.
  
  
  OBJECTIVE
  We sought to investigate the presence of genes conferring resistance to aminoglycosides, specially to gentamicin, in Klebsiella pneumoniae and Escherichia coli multidrug-resistant strains isolated from different clinical materials among patients hospitalized in a university hospital in Rio de Janeiro, Brazil.
  
  
  METHODS
  Ten colonization strains and 20 infection strains were evaluated during three decades (1980 to 2010) using selective media containing 8 µg/ml of gentamicin. Thirty strains were tested for antimicrobial susceptibility. Twenty two strains were subjected to plasmid DNA extraction and 12 to hybridization assays using as probe a 1.9 kb plasmid DNA fragment from one of the K. pneumoniae strains isolated from faecal samples. This fragment was sequenced and assigned to the GQ422439 GenBank record. PCR was also performed using oligonucleotides designed for aminoglycoside-modifying enzymes.
  
  
  RESULTS
  An accC2 acetylase, besides transposons and insertion sequences, were evidenced. Twenty-four (80%) of the isolates were positive for the aacC2 gene in agreement with antibiotic susceptibility testing profiles, indicating the persistent presence of this gene throughout the three decades. We detected high molecular weight plasmids in 54,5% of the strains. Of the tested strains, 91% showed positive signal in the hybridization assays.
  
  
  CONCLUSIONS
  A gene codifying for one specific aminoglycoside-modifying enzyme was detected all throughout the three decades. Our data back the adoption of preventive measures, such as a more conscious use of antimicrobial agents in hospital environments, which can contribute to control the dissemination of microorganisms harboring resistance gene plasmids.
authors.affiliation: Departamento de Microbiologia, Inmunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Verônica
authors.initials: V
authors.lastname: Dias-Gonçalves
authors.affiliation: Departamento de Microbiologia, Inmunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Françoise
authors.initials: F
authors.lastname: Bohrer-Lengruber
authors.affiliation: Departamento de Microbiologia, Inmunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Bianca
authors.initials: B
authors.lastname: Oliveira-Fonseca
authors.affiliation: Laboratório de Parasitologia Molecular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio, Rio de Janeiro, Brasil.
authors.forename: Renata Meirelles
authors.initials: RM
authors.lastname: Santos-Pereira
authors.affiliation: Laboratório de Genética Molecular, Campus Maracanã, Federal de Educação, Ciência e Tecnologia de Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Luis Dione
authors.initials: LD
authors.lastname: Barbosa de Melo
authors.affiliation: Laboratório de Parasitologia Molecular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio, Rio de Janeiro, Brasil.
authors.forename: Ulisses
authors.initials: U
authors.lastname: Gazos-Lopes
authors.affiliation: Departamento de Microbiologia, Inmunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Ribeiro-Bello
authors.affiliation: Departamento de Microbiologia, Inmunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: José Augusto
authors.initials: JA
authors.lastname: Adler-Pereira
mesh_terms: D000617:Aminoglycosides / Q000235:genetics*; D001938:Brazil; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D005798:Genes, Bacterial; D006785:Hospitals, University; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D013997:Time Factors
chemical_list: D000617:Aminoglycosides