title: Polymyxin resistance caused by mgrB inactivation is not associated with significant biological cost in Klebsiella pneumoniae.
abstract: The inactivation of the mgrB gene, which encodes a negative-feedback regulator of the PhoPQ signaling system, was recently shown to be a common mutational mechanism responsible for acquired polymyxin resistance among carbapenemase-producing Klebsiella pneumoniae strains from clinical sources. In this work, we show that mgrB mutants can easily be selected in vitro from different K. pneumoniae lineages, and mgrB inactivation is not associated with a significant biological cost.
authors.affiliation: Department of Medical Biotechnologies, University of Siena, Siena, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Cannatelli
authors.affiliation: Department of Animal Health and VISAVET, Complutense University of Madrid, Madrid, Spain.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Santos-Lopez
authors.affiliation: Department of Medical Biotechnologies, University of Siena, Siena, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Giani
authors.affiliation: Department of Animal Health and VISAVET, Complutense University of Madrid, Madrid, Spain.
authors.forename: Bruno
authors.initials: B
authors.lastname: Gonzalez-Zorn
authors.affiliation: Department of Medical Biotechnologies, University of Siena, Siena, Italy Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy Clinical Microbiology and Virology Unit, Florence Careggi University Hospital, Florence, Italy gianmaria.rossolini@unifi.it.
authors.forename: Gian Maria
authors.initials: GM
authors.lastname: Rossolini
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D007710:Klebsiella Infections / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D011113:Polymyxins / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D011113:Polymyxins