Please use this identifier to cite or link to this item:
Title: A novel mutation in pmrB mediates colistin resistance during therapy of acinetobacter baumannii
Authors: Dahdouh, Elias
Gómez-Gil, Rosa
Sanz, Sonia
González-Zorn, Bruno
Daoud, Ziad
Mingorance, Jesús
Suárez, Monica
Affiliations: Faculty of Medicine 
Keywords: Acinetobacter baumannii
Colistin resistance
PmrCAB operon
Whole-genome sequencing
Subjects: Virulence
Issue Date: 2017
Part of: International journal of antimicrobial agents
Volume: 49
Issue: 6
Start page: 727
End page: 733
Acinetobacter baumannii is a highly versatile nosocomial pathogen. Multidrug resistance among A. baumannii isolates led to the use of colistin, subsequently giving rise to colistin-resistant strains. In this study, the genetic and phenotypic profiles of two colistin-resistant A. baumannii isolates were investigated. Two A. baumannii isolates were obtained from Patient 1 (C071 and C440) and three isolates were obtained from Patient 2 (C080, C314 and C428). Susceptibility profiles were determined by VITEK®2 and Etest. Clonality was determined by RAPD analysis and trilocus multiplex PCR. The pmrCAB operon was sequenced and common carbapenemase genes were screened for by PCR. Doubling times, haemolysis, surface motility, biofilm formation, siderophore production and proteolytic activity were phenotypically determined. Finally, whole-genome sequencing was performed for all five isolates. Isolates C440 and C428 were resistant to colistin and were clonally identical to their sensitive counterparts. The cause of colistin resistance was traced to the previously described P233S mutation in pmrB of C440 and to a novel ΔI19 mutation in pmrB of C428. blaOXA-58-like and blaGES-5 from the strains of Patients 1 and 2, respectively, were also detected. C440 had attenuated proteolytic activity and was positive for siderophore production compared with C071. No difference in in vitro virulence was detected between isolates C080, C314 and C428. In conclusion, one common and one novel mutation were encountered in pmrB from two distinct colistin-resistant A. baumannii isolates. These mutations caused colistin resistance during therapy in two distinct clones, and only one of them had altered in vitro virulence.
DOI: 10.1016/j.ijantimicag.2017.01.031
Ezproxy URL: Link to full text
Type: Journal Article
Appears in Collections:Faculty of Medicine

Show full item record


checked on May 15, 2021

Google ScholarTM


Dimensions Altmetric

Dimensions Altmetric

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.