title: Structural Alteration of OmpR as a Source of Ertapenem Resistance in a CTX-M-15-Producing Escherichia coli O25b:H4 Sequence Type 131 Clinical Isolate.
abstract: In this study, an ertapenem-nonsusceptibleEscherichia coliisolate was investigated to determine the genetic basis for its carbapenem resistance phenotype. This clinical strain was recovered from a patient that received, 1 year previously, ertapenem to treat a cholangitis due to a carbapenem-susceptible extended-spectrum-β-lactamase (ESBL)-producingE. coliisolate. Whole-genome sequencing of these strains was performed using Illumina and single-molecule real-time sequencing technologies. It revealed that they belonged to the ST131 clonal group, had the predicted O25b:H4 serotype, and produced the CTX-M-15 and TEM-1 β-lactamases. One nucleotide substitution was identified between these strains. It affected theompRgene, which codes for a regulatory protein involved in the control of OmpC/OmpF porin expression, creating a Gly-63-Val substitution. The role of OmpR alteration was confirmed by a complementation experiment that fully restored the susceptibility to ertapenem of the clinical isolate. A modeling study showed that the Gly-63-Val change displaced the histidine-kinase phosphorylation site. SDS-PAGE analysis revealed that the ertapenem-nonsusceptibleE. colistrain had a decreased expression of OmpC/OmpF porins. No significant defect in the growth rate or in the resistance toDictyostelium discoideumamoeba phagocytosis was found in the ertapenem-nonsusceptibleE. coliisolate compared to its susceptible parental strain. Our report demonstrates for the first time that ertapenem resistance may emerge clinically from ESBL-producingE. colidue to mutations that modulate the OmpR activity.
authors.affiliation: Département d'Anesthésie-Réanimation, CHU Amiens-Picardie, and INSERM U1088, Université de Picardie Jules Verne, Amiens, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Dupont
authors.affiliation: INSERM, IAME, UMR 1137, Paris, France.|Université de Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France.
authors.forename: Pascaline
authors.initials: P
authors.lastname: Choinier
authors.affiliation: UMR 8030, CNRS, Université Évry-Val-d'Essonne, CEA, Institut de Génomique-Genoscope, Laboratoire d'Analyses Bioinformatiques pour la Génomique et le Métabolisme and Laboratoire d'Informatique Scientifique, Évry, France.
authors.forename: David
authors.initials: D
authors.lastname: Roche
authors.affiliation: Institut de Biologie de l'Ecole Normale Supérieure, ENS, CNRS UMR8197, INSERM U1024, Paris, France.
authors.forename: Sandine
authors.initials: S
authors.lastname: Adiba
authors.affiliation: INSERM, IAME, UMR 1137, Paris, France.|Université de Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France.
authors.forename: Megan
authors.initials: M
authors.lastname: Sookdeb
authors.affiliation: INSERM, IAME, UMR 1137, Paris, France.|Université de Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Branger
authors.affiliation: INSERM, IAME, UMR 1137, Paris, France.|Université de Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France.|APHP, Hôpital Bichat Claude Bernard, Laboratoire de Génétique Moléculaire, Paris, France.
authors.forename: Erick
authors.initials: E
authors.lastname: Denamur
authors.affiliation: INSERM, IAME, UMR 1137, Paris, France hedi.mammeri@wanadoo.fr.|Université de Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France.|APHP, Hôpital Bichat Claude Bernard, Laboratoire de Bactériologie, Paris, France.
authors.forename: Hedi
authors.initials: H
authors.lastname: Mammeri
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D000073182:Carbapenem-Resistant Enterobacteriaceae / Q000235:genetics; D002761:Cholangitis / Q000382:microbiology; D004023:Dictyostelium / Q000378:metabolism / Q000382:microbiology; D024881:Drug Resistance, Bacterial / Q000235:genetics; D000077727:Ertapenem; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000188:drug therapy; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010587:Phagocytosis / Q000502:physiology; D018272:Porins / Q000096:biosynthesis; D015534:Trans-Activators / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism; D047090:beta-Lactams / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C113724:OmpC protein; C109237:OmpF protein; D018272:Porins; D015534:Trans-Activators; D047090:beta-Lactams; C112177:osmolarity response regulator proteins; C473109:beta-lactamase CTX-M-15; D001618:beta-Lactamases; D000077727:Ertapenem
keywords: ESBL; OmpR; ST131; avibactam; carbapenem; envZ; temocillin