Detection of Colistin Resistance in Salmonella enterica Using MALDIxin Test on the Routine MALDI Biotyper Sirius Mass Spectrometer

Laurent Dortet; Rémy A Bonnin; Simon Le Hello; Laetitia Fabre; Richard Bonnet; Markus Kostrzewa; Alain Filloux; Gerald Larrouy-Maumus

doi:10.3389/fmicb.2020.01141

Detection of Colistin Resistance in Salmonella enterica Using MALDIxin Test on the Routine MALDI Biotyper Sirius Mass Spectrometer

Front Microbiol. 2020 Jun 3:11:1141. doi: 10.3389/fmicb.2020.01141. eCollection 2020.

Authors

Laurent Dortet^{1

2

3

4}, Rémy A Bonnin^{2

3

4}, Simon Le Hello⁵, Laetitia Fabre⁵, Richard Bonnet^{4

6}, Markus Kostrzewa⁷, Alain Filloux¹, Gerald Larrouy-Maumus¹

Affiliations

¹ MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, United Kingdom.
² Department of Bacteriology-Hygiene, Bicêtre Hospital, Assistance Publique - Hôpitaux de Paris, Le Kremlin-Bicêtre, France.
³ EA7361 "Structure, Dynamic, Function and Expression of Broad Spectrum ß-Lactamases", Paris-Sud University, LabEx Lermit, Faculty of Medecine, Le Kremlin-Bicêtre, France.
⁴ French National Reference Centre for Antibiotic Resistance, Le Kremlin-Bicêtre, France.
⁵ Institut Pasteur, French National Reference Centre for E. coli, Shigella and Salmonella, Paris, France.
⁶ Department of Bacteriology, University Hospital of Clermont-Ferrand, Clermont-Ferrand, France.
⁷ Bruker Daltonik GmbH, Bremen, Germany.

Abstract

Resistance to polymyxins in most Gram-negative bacteria arises from chemical modifications to the lipid A portion of their lipopolysaccharide (LPS) mediated by chromosomally encoded mutations or the recently discovered plasmid-encoded mcr genes that have further complicated the landscape of colistin resistance. Currently, minimal inhibitory concentration (MIC) determination by broth microdilution, the gold standard for the detection of polymyxin resistance, is time consuming (24 h) and challenging to perform in clinical and veterinary laboratories. Here we present the use of the MALDIxin to detect colistin resistant Salmonella enterica using the MALDxin test on the routine matrix-assisted laser desorption ionization (MALDI) Biotyper Sirius system.

Keywords: MALDI mass spectrometry; Salmonella enterica; colistin; diagno stic; lipid A.

Abstract

Grants and funding