Detection of colistin-resistant Gram-negative rods by using the SuperPolymyxin medium

Aurélie Jayol; Laurent Poirel; Catherine André; Véronique Dubois; Patrice Nordmann

doi:10.1016/j.diagmicrobio.2018.05.008

Detection of colistin-resistant Gram-negative rods by using the SuperPolymyxin medium

Diagn Microbiol Infect Dis. 2018 Oct;92(2):95-101. doi: 10.1016/j.diagmicrobio.2018.05.008. Epub 2018 May 17.

Authors

Aurélie Jayol¹, Laurent Poirel², Catherine André³, Véronique Dubois⁴, Patrice Nordmann⁵

Affiliations

¹ Laboratory of Bacteriology, Bordeaux University Hospital, Bordeaux, France; CNRS UMR5234, University of Bordeaux, Bordeaux,, France; Emerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Department of Medicine, University of Fribourg, Fribourg, Switzerland; Swiss National Reference Center for Emerging Antibiotic Resistance, Fribourg, Switzerland.
² Emerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Department of Medicine, University of Fribourg, Fribourg, Switzerland; Swiss National Reference Center for Emerging Antibiotic Resistance, Fribourg, Switzerland; INSERM European Unit (LEA), IAME, Paris, France. Electronic address: laurent.poirel@unifr.ch.
³ CNRS UMR5234, University of Bordeaux, Bordeaux,, France.
⁴ Laboratory of Bacteriology, Bordeaux University Hospital, Bordeaux, France; CNRS UMR5234, University of Bordeaux, Bordeaux,, France.
⁵ Emerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Department of Medicine, University of Fribourg, Fribourg, Switzerland; Swiss National Reference Center for Emerging Antibiotic Resistance, Fribourg, Switzerland; INSERM European Unit (LEA), IAME, Paris, France; University of Lausanne and University Hospital Center, Lausanne, Switzerland.

PMID: 29885757
DOI: 10.1016/j.diagmicrobio.2018.05.008

Abstract

The commercial SuperPolymyxin medium (ELITechGroup, Puteaux, France), currently licensed in Europe, is aimed to screen for either intrinsic or acquired colistin resistance in Gram negatives. It was tested for screening colistin-resistant Gram-negative rods from bacterial cultures of 145 colistin-resistant and 86 colistin-susceptible Gram-negative rods isolates. It exhibited a sensitivity and specificity of 95.2% (138/145) and 95.3% (82/86), respectively. The sensitivity for the detection of the 25 isolates carrying plasmid-mediated colistin resistance genes (mcr-1, mcr-2, mcr-3, and mcr-4) from bacterial cultures was of 100%. It was also evaluated for the detection of colistin-resistant Gram-negative rods from 57 rectal swab samples (41 clinical rectal swab samples and from 16 spiked rectal swab samples supplemented with colistin-resistant enterobacterial isolates carrying mcr genes). The overall sensitivity and specificity were of 100% (33/33) and 90.3% (56/62), respectively. The detection of isolates carrying plasmid-mediated mcr-like genes from rectal swabs was achieved with a lowest detection limit of 10³ to 10⁴ CFU/mL. The SuperPolymyxin medium is adapted for screening and detection of colistin-resistant isolates from bacterial cultures and rectal swab samples, regardless of the level and the mechanism of colistin resistance. It might be useful in the context of prevention of outbreaks due to colistin-resistant isolates and for epidemiological surveillance.

Keywords: Colistin; MCR; Resistance; SuperPolymyxin medium; Susceptibility testing.

MeSH terms

Anti-Bacterial Agents / pharmacology*
Colistin / pharmacology*
Culture Media*
Drug Resistance, Bacterial*
Enterobacteriaceae / drug effects
Enterobacteriaceae / isolation & purification
Gram-Negative Bacteria / drug effects*
Gram-Negative Bacteria / isolation & purification
Humans
Microbial Sensitivity Tests
Plasmids
Polymyxins*
Reagent Kits, Diagnostic

Substances

Anti-Bacterial Agents
Culture Media
Polymyxins
Reagent Kits, Diagnostic
Colistin