Evaluation of the Rapid Polymyxin NP test and its industrial version for the detection of polymyxin-resistant Enterobacteriaceae

Aurélie Jayol (1) , Nicolas Kieffer (1) , Laurent Poirel (1) , François Guérin (2) , Deniz Güneser (1) , Vincent Cattoir (3, 4) , Patrice Nordmann (1, 5)

1 UNIFR - Université de Fribourg = University of Fribourg
2 U2RM - Unité de Recherche Risques Microbiens
3 BRM - ARN régulateurs bactériens et médecine
4 Centre Hospitalier Universitaire de Rennes [CHU Rennes] = Rennes University Hospital [Ponchaillou]
5 UNIL - Université de Lausanne = University of Lausanne

The commercial Rapid Polymyxin NP test was evaluated to detect colistin-resistant Enterobacteriaceae. A total of 223 enterobacterial isolates corresponding to 136 resistant (including 38 MCR-like producers), 19 heteroresistant, and 78 colistin-susceptible isolates were tested. The test was performed according to the manufacturer's instruction, and the color of the wells was read after 2 and 3 hours of incubation. The results were compared with those of the homemade Rapid Polymyxin NP test, and manual broth microdilution according to EUCAST guidelines was used as the reference method to determine the performance of the test. Excellent performance of the commercial Rapid Polymyxin NP test was found with a very major error rate, a major error rate, a sensitivity, and a specificity of 1.9%, 5.1%, 98.1%, and 94.9%, respectively. The performance of the homemade Polymyxin NP test was similar, with a slightly better value for the very major error (1.2 %).

Mots clés: Enterobacteriaceae; MCR; Polymyxin; Rapid test

Domaines: Virologie; Protistologie; Mycologie; Bactériologie

Aurélie Jayol, Nicolas Kieffer, Laurent Poirel, François Guérin, Deniz Güneser, et al.. Evaluation of the Rapid Polymyxin NP test and its industrial version for the detection of polymyxin-resistant Enterobacteriaceae. Diagnostic Microbiology and Infectious Disease, 2018, 92 (2), pp.90-94. ⟨10.1016/j.diagmicrobio.2018.05.006⟩. ⟨hal-02155530⟩