title: Transferable plasmid mediating resistance to multiple antimicrobial agents in Klebsiella pneumoniae isolates in Greece.
abstract: OBJECTIVE
  To investigate the underlying resistance mechanisms in 10 Klebsiella pneumoniae isolates.
  
  
  METHODS
  Ten K. pneumoniae strains according to distinct bacteriocin typing and REP-PCR, were examined for their plasmid content, their ability to transfer their resistance to aminoglycosides and third-generation cephalosporins, and their production of aminoglycoside-modifying enzymes and beta-lactamases.
  
  
  RESULTS
  Transfer of resistance to the above-mentioned antibiotics as well as to co-trimoxazole and tetracycline in Escherichia coli strain RC 85 at a frequency of 5-106 was achieved for all strains by conjugation. Similar strains harbor a self-transferable multiresistant plasmid (80 kb) with similar EcoRI and HindIII restriction patterns. This plasmid encodes an extended-spectrum beta-lactamase which confers high-level resistance to third-generation cephalosporins and aztreonam. It produces SHV-5 beta-lactamase, as demonstrated by isoelectric focusing and DNA sequencing. Aminoglycoside resistance was co-transferred, and AAC(6')-I, mediating resistance to gentamicin, tobramycin, netilmicin and amikacin, and AAC(3)-I, mediating resistance to gentamicin and sisomycin, were encoded in all isolates and their transconjugants, while APH(3')-I, mediating resistance to kanamycin and neomycin, was encoded in seven strains.
  
  
  CONCLUSIONS
  It appears that a multiresistant transferable plasmid encoding the SHV-5 beta-lactamase, causing unusually high resistance to ceftazidime and aztreonam, and the combination AAC(6')-I + AAC(3)-I of acetylating enzymes causing, also resistance to all clinically available aminoglycosides, is established in K. pneumoniae in Greece.
authors.affiliation: 4th Department of Internal Medicine, Molecular Biology Section, University of Athens Medical School, Athens, Greece.
authors.forename: I
authors.initials: I
authors.lastname: Galani
authors.forename: E
authors.initials: E
authors.lastname: Xirouchaki
authors.forename: K
authors.initials: K
authors.lastname: Kanellakopoulou
authors.forename: G
authors.initials: G
authors.lastname: Petrikkos
authors.forename: H
authors.initials: H
authors.lastname: Giamarellou
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003428:Cross Infection; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D006115:Greece; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids
chemical_list: D000900:Anti-Bacterial Agents