Abstract
We report a Serratia marcescens and an Escherichia coli isolate simultaneously detected in the same patient. Both isolates showed susceptibility patterns suggestive of harbouring a plasmid-mediated AmpC β-lactamase (pACBL) and a plasmid-encoded quinolone resistance (PMQR). PCR-based replicon, MOB typing, plasmid profile and Southern hybridization analyses revealed that both isolates coharboured blaDHA-1 and qnrB genes on the same IncL/M-MOBP13 plasmid approximately 70 kb in size. Together with the fact that both plasmids were conjugative in the laboratory, these results strongly suggest that a horizontal transfer event could take place in vivo. This is the first report of an isolate of S. marcescens harbouring a pACBL. The only phenotypic method that suggests the presence of a pACBL in an isolate harbouring an inducible chromosomal AmpC enzyme is the observation of scattered colonies near the edge of the inhibition zones of some β-lactams. The presence of both resistance genes on the same plasmid and the reported increase in PMQR could perhaps explain the widespread distribution of blaDHA-1 genes. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd.
Original language | English |
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Pages (from-to) | 24-28 |
Journal | FEMS Microbiology Letters |
Volume | 308 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 Jan 2010 |
Keywords
- Enterobacteriaceae
- Incompatibility groups
- Plasmid-mediated quinolone resistance
- Plasmid-mediated β-lactamases
- Relaxases