We investigated the presence of beta-lactamase genes (bla) in twenty-six Enterobacteriaceae strains already found positive for qnrS1 plasmid-mediated quinolone resistance determinant. Three K. pneumoniae strains isolated in the period 2008-2009 at the University Hospital in Verona, were positive for LAP-2 narrow-spectrum beta-lactamase. The strains, namely VRB586, VRE185 and VRE196, were cultured from urine, bile and peritoneal drainage, respectively of different patients and unit. The blaLAP-2 and qnrS1 resistance determinants were separated by ISEcl2 and were located on a 97 kb conjugable and untypable plasmid transferred to the recipient strain E. coli J53. The fluoroquinolone and ceftazidime MICs increased 1-2 folds in the trans-conjugant cells. The three K. pneumoniae strains were clonal by PFGE and belonged to ST147 internationally successful clone by MLST. Plasmid sequence including ISEcl2 and qnrS1 in K. pneumoniae ST147 was found highly similar to earlier detectedqnrS1-harbouring plasmids suggesting a stable genetic structure and a common source of the resistance determinant. To the best of our knowledge this is the first report of the internationally successful K. pneumoniae ST147 carrying blaLAP-2 and qnrS1 while the first detection of LAP beta-lactamase in Italy.
Identification of blaLAP-2 and qnrS1 in Klebsiella pneunmoniae ST147 internationally successful clone
KOCSIS, Bela;KOCSIS, Erika;FONTANA, Roberta;CORNAGLIA, Giuseppe;MAZZARIOL, Annarita
2013
Abstract
We investigated the presence of beta-lactamase genes (bla) in twenty-six Enterobacteriaceae strains already found positive for qnrS1 plasmid-mediated quinolone resistance determinant. Three K. pneumoniae strains isolated in the period 2008-2009 at the University Hospital in Verona, were positive for LAP-2 narrow-spectrum beta-lactamase. The strains, namely VRB586, VRE185 and VRE196, were cultured from urine, bile and peritoneal drainage, respectively of different patients and unit. The blaLAP-2 and qnrS1 resistance determinants were separated by ISEcl2 and were located on a 97 kb conjugable and untypable plasmid transferred to the recipient strain E. coli J53. The fluoroquinolone and ceftazidime MICs increased 1-2 folds in the trans-conjugant cells. The three K. pneumoniae strains were clonal by PFGE and belonged to ST147 internationally successful clone by MLST. Plasmid sequence including ISEcl2 and qnrS1 in K. pneumoniae ST147 was found highly similar to earlier detectedqnrS1-harbouring plasmids suggesting a stable genetic structure and a common source of the resistance determinant. To the best of our knowledge this is the first report of the internationally successful K. pneumoniae ST147 carrying blaLAP-2 and qnrS1 while the first detection of LAP beta-lactamase in Italy.
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