Details

Autor(en) / Beteiligte

• Pfeifer, Yvonne
• Wilharm, Gottfried
• Zander, Esther
• Wichelhaus, Thomas A
• Göttig, Stefan
• Hunfeld, Klaus-Peter
• Seifert, Harald
• Witte, Wolfgang
• Higgins, Paul G

Titel

Molecular characterization of bla NDM-1 in an Acinetobacter baumannii strain isolated in Germany in 2007

Ist Teil von

• Journal of antimicrobial chemotherapy, 2011-09, Vol.66 (9), p.1998-2001

Ort / Verlag

Oxford University Press

Erscheinungsjahr

2011

Quelle

Oxford Journals 2020 Medicine

Beschreibungen/Notizen

• Objectives To investigate the genetic environment of the metallo-β-lactamase gene bla NDM-1 in an Acinetobacter baumannii isolated in 2007 in a German hospital. Methods Antimicrobial susceptibility testing was performed and resistance genes were characterized by PCR amplification and sequencing. Transferability of β-lactam resistance was tested by broth mating assays and transformation of plasmids. The genetic background of bla NDM-1 was analysed by primer walking. Typing of the A. baumannii strain was performed by repetitive extragenic palindromic sequence-based PCR (rep-PCR) using the DiversiLab system. Results The multidrug-resistant A. baumannii isolate harboured β-lactamase genes bla NDM-1 and intrinsic bla OXA-64, but without the insertion sequence ISAba1 often located upstream. Transfer of carbapenem resistance by conjugation and transformation failed. Hybridization of isolated plasmid DNA with bla NDM probes was not successful. Shotgun cloning of whole genomic DNA and sequence analyses revealed that bla NDM-1 was located between two insertion elements of ISAba125. Furthermore, this bla NDM-1-containing transposon structure was integrated into a chromosomal gene encoding a putative A. baumannii major facilitator superfamily (MFS) metabolite/H+ symporter. Conclusions The metallo-β-lactamase gene bla NDM-1 in this A. baumannii strain was integrated in the chromosome on a new transposon structure composed of two copies of insertion sequence ISAba125. The variability of the genetic environment of bla NDM-1 likely facilitates the rapid dissemination of this gene within many Gram-negative bacterial species.