A selective culture medium for screening linezolid-resistant gram-positive bacteria

Patrice Nordmann; Angel Rodríguez-Villodres; Laurent Poirel

doi:10.1016/j.diagmicrobio.2019.03.006

A selective culture medium for screening linezolid-resistant gram-positive bacteria

Diagn Microbiol Infect Dis. 2019 Sep;95(1):1-4. doi: 10.1016/j.diagmicrobio.2019.03.006. Epub 2019 Mar 21.

Authors

Patrice Nordmann¹, Angel Rodríguez-Villodres², Laurent Poirel³

Affiliations

¹ Medical and Molecular Microbiology Unit, Department of Medicine, Faculty of Science, University of Fribourg, Fribourg, Switzerland; INSERM European Unit (IAME, France), University of Fribourg; Swiss National Reference Center for Emerging Antibiotic Resistance (NARA), Fribourg, Switzerland; Institute for Microbiology, University of Lausanne and University Hospital Centre, Lausanne, Switzerland. Electronic address: patrice.nordmann@unifr.ch.
² Medical and Molecular Microbiology Unit, Department of Medicine, Faculty of Science, University of Fribourg, Fribourg, Switzerland; Clinical Unit of Infectious Diseases, Microbiology and Preventive Medicine, University Hospital Virgen del Rocío, Seville, Spain; Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain.
³ Medical and Molecular Microbiology Unit, Department of Medicine, Faculty of Science, University of Fribourg, Fribourg, Switzerland; INSERM European Unit (IAME, France), University of Fribourg; Swiss National Reference Center for Emerging Antibiotic Resistance (NARA), Fribourg, Switzerland.

PMID: 30981556
DOI: 10.1016/j.diagmicrobio.2019.03.006

Abstract

The SuperLinezolid medium was developed for screening resistance to linezolid (LZD) in Gram-positive bacteria (Staphylococcus spp., Enterococcus spp.). It was evaluated using LZD-susceptible (n = 20) and LZD-resistant (n = 17) Gram-positive isolates. The sensitivity was found to be 82% at 24 h (3 out of 17 isolates being missed), and reached 100% at 48 h. At 48 h, a single LZD-susceptible isolate grew (specificity 95%). By testing stools spiked with LZD-resistant Gram-positive strains, an excellent performance of the medium was observed, with a lowest detection limit ranging from 10¹ to 10² CFU/ml. Overall, this medium is accurate for detection of LZD-resistant Gram-positive isolates after 24 h of culture.

Keywords: Antibiotic; Enterococci; Linezolid; Screening; Staphylococci.

MeSH terms

Anti-Bacterial Agents / analysis
Anti-Bacterial Agents / pharmacology*
Bacteriological Techniques / methods*
Culture Media* / chemistry
Drug Resistance, Bacterial*
Enterococcus / drug effects
Enterococcus / isolation & purification
Feces / microbiology
Gram-Positive Bacteria / drug effects*
Gram-Positive Bacteria / isolation & purification
Humans
Linezolid / analysis
Linezolid / pharmacology*
Microbial Sensitivity Tests
Sensitivity and Specificity
Staphylococcus / drug effects
Staphylococcus / isolation & purification

Substances

Anti-Bacterial Agents
Culture Media
Linezolid