High Prevalence of SXT/R391-Related Integrative and Conjugative Elements Carrying blaCMY-2 in Proteus mirabilis Isolates from Gulls in the South of France

Abstract

The genetic structures involved in the dissemination of blaCMY-2 carried by Proteus mirabilis isolates recovered from different gull species in the South of France were characterized and compared to clinical isolates. blaCMY-2 was identified in P. mirabilis isolates from 27/93 yellow-legged gulls and from 37/65 slender-billed gulls. It was carried by a conjugative SXT/R391-like integrative and conjugative element (ICE) in all avian strains and in 3/7 human strains. Two clinical isolates had the same genetic background as six avian isolates.

FIG 1

Dendrogram of P. mirabilis isolates carrying the bla_CMY-2 genes. YL, yellow-legged gull isolates; SB, slender-billed gull isolates; H, human isolates.

FIG 2

Genetic organization of the SXT/R391-like ICE carrying bla_CMY-2 in P. mirabilis. The same molecular structure was observed in all 64 bla_CMY-2-positive avian strains and in 3/7 (42.9%) human strains. This structure was similar to that of ICEPmiJpn1 (GenBank accession no. AB525688). Light gray arrows represent the conserved genes of the ICE. Dark gray arrows represent genes carried by the Tn10 composite transposon. Black arrows represent the bla_CMY-2 gene. Thin black lines represent the different primers used to explore this region. (A) Partial sequence of ICEPmiJpn1 used as a template for PCR mapping. (B) Schematic representation of the regions amplified and sequenced in this study.