Contribution of IncFII and broad-host IncA/C and IncN plasmids to the local expansion and diversification of phylogroup B2 Escherichia coli ST131 clones carrying bla CTX-M-15and qnrS1 genes

Abstract

The recent increase of CTX-M-15-producing Escherichia coli isolates in our institution was caused by diverse clonal backgrounds, including mainly B2 sequence type 131 (ST131) clones presenting variable virulence profiles but also A 1 (ST617, ST410), B1, and D 1 (ST405) clones. Besides IncFII-pC15-1a, we detected multidrug-resistant IncA/C 2 and IncN plasmids carrying bla CTX-M-15 and/or qnrS1. Our study highlights the diversification of highly transmissible resistant and virulent clones and the recombinogenic potential of broad-host plasmids contributing to the expansion of genetic regions coding for multidrug resistance to other bacterial lineages. Copyright © 2012, American Society for Microbiology. All Rights Reserved.