Real-time PCR for detection of plasmid-mediated polymyxin resistance (mcr-1) from cultured bacteria and stools.
The aim of the study was to develop a simple assay for rapid detection of the mcr-1 gene, recently identified as a source of plasmid-mediated acquired resistance to polymyxins in Enterobacteriaceae.



A SYBR Green-based real-time PCR assay was designed for detection of the mcr-1 gene. This assay was applied to cultured bacteria and to spiked human and cattle stools.



The mcr-1 gene could be detected with a lower limit of 10(2) cultured bacteria. This test was highly sensitive and specific, and generated no false-positive results. The assay was also conclusive when applied to stools spiked with mcr-1-positive Escherichia coli.



This simple, rapid, sensitive and specific assay will be useful for rapid screening of this resistance trait in both human medicine and veterinary medicine.
Emerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Department of Medicine, Faculty of Science, University of Fribourg, Fribourg, Switzerland.
Séverine
S
Bontron
Emerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Department of Medicine, Faculty of Science, University of Fribourg, Fribourg, Switzerland laurent.poirel@unifr.ch.
Laurent
L
Poirel
Emerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Department of Medicine, Faculty of Science, University of Fribourg, Fribourg, Switzerland Hôpital Cantonal HFR, Fribourg, Switzerland.
Patrice
P
Nordmann
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D052160:Benzothiazoles; D002417:Cattle; D003959:Diamines; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000235:genetics; D005243:Feces / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009930:Organic Chemicals; D010957:Plasmids; D011113:Polymyxins / Q000494:pharmacology*; D011804:Quinolines; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013194:Staining and Labeling; D013997:Time Factors
D000900:Anti-Bacterial Agents; D052160:Benzothiazoles; D003959:Diamines; D009930:Organic Chemicals; D011113:Polymyxins; D011804:Quinolines; C098022:SYBR Green I