12 TH OIE SEMINAR to be held during the 18 th WAVLD Symposium, Sorrento (Italy), 7 10 June 2017 MORNING SESSION: ANTIMICROBIAL RESISTANCE AND RAPID DIAGNOSTICS Validation of Rapid Diagnostic Tests for Antimicrobial Resistance Sophie Granier Antimicrobial resistance team Mission Antibiorésistance Laboratoire de Sécurité des Aliments
12 TH OIE SEMINAR to be held during the 18 th WAVLD Symposium, Sorrento (Italy), 7 10 June 2017 MORNING SESSION: ANTIMICROBIAL RESISTANCE AND RAPID DIAGNOSTICS clinicians need tools to ensure the relevance of the prescription Terminology issue
12 TH OIE SEMINAR to be held during the 18 th WAVLD Symposium, Sorrento (Italy), 7 10 June 2017 Antimicrobial Resistance : back to basics
Antimicrobial Resistance Intrinsic resistance = resistance displayed by EACH bacterial strain from a specific bacterial species V.Jarlier Acquired resistance = due to a modification of their gene pool, resistance is displayed by PART OF bacterial strains from a specific bacterial species
Antibiogram phenotypical evidence of resistance in vitro measurement of an antibiotic activity against the targeted bacteria MIC = minimal inhibitory concentration of an antimicrobial to inhibate visible bacterial growth Disc diffusion antibiogram Sensu stricto Agar dilution Gradient strips Microdilution Ref Method Leadtime for result : minimum 1 day (culture) + 1 day (measure)
Antibiogram - interpretation Where do criteria come from? www. CLSI.org www.eucast.org US$ 170 per document Specific vet guidelines Free, not complete yet
Antimicrobial resistance : 2 points of view Epidemiologist vs Clinician Epidemiologist : Resistant Bacteria = bacteria that acquired any resistance mechanism against antibiotica Clinician : Resistant Bacteria = Bacteria whose growth will not be (enough) inhibited by antibiotic A to predict therapeutic success in case of infections
12 TH OIE SEMINAR to be held during the 18 th WAVLD Symposium, Sorrento (Italy), 7 10 June 2017 Antimicrobial Resistance : A terminology issue?
Antimicrobial resistance and terminology: Even the specialists don t understand each other
Hattie Webb s research On phenotypic characterization of colistine resistance «Sophie, why for god sake are you» 10
Antimicrobial resistance : 2 points of view Epidemiologist vs Clinician Epidemiologist : Resistant Bacteria = bacteria that acquired any resistance mechanism against antibiotica Clinician : Resistant Bacteria = Bacteria whose growth will not be (enough) inhibited by antibiotic A to predict therapeutic success in case of infections
Bacterial identification and intrinsic resistance profile is essential to perform and interpret antimicrobial susceptibility tests
Bacterial identification and intrinsic resistance profile is essential to perform and interpret antimicrobial susceptibility tests X
12 TH OIE SEMINAR to be held during the 18 th WAVLD Symposium, Sorrento (Italy), 7 10 June 2017 MORNING SESSION: ANTIMICROBIAL RESISTANCE AND RAPID DIAGNOSTICS How to validate alternative methods? Objectives set here: Rapid test to support prescription Validate interpretation (qualitative method)
New method : performance to be assessed Intra-laboratory Inter -laboratory Miscellaneous Specificity Sensitivity Fidelity : Repeatability Intermediate fidelity (= intralaboratory reproducibility (limit of detection) Reproducibility Repeatability Specificity Sensitivity (limit of detection) Duration of the test Cost Material and installation needed Workers qualification False positive rate False negative rate Same lab/same technician/ short time Same lab/diff technicians False positive rate False negative rate
New method : reference material Reference strains : o Known AMR profile o Available worldwide
Validation of Rapid Diagnostic Tests for Antimicrobial Resistance : to explore further
Validation of Rapid Diagnostic Tests for Antimicrobial Resistance : take home message Define precisely the service expected from the test Bacterial identification and knowlegde of intrinsic resistance profile is essential to perform and interpret any antimicrobial susceptibility test One «test» fits all?
12 TH OIE SEMINAR to be held during the 18 th WAVLD Symposium, Sorrento (Italy), 7 10 June 2017 Anses Groupe GT Val2 Anses Pole Antibiorésistance Acknowledgements Sophie Granier sophie.granier@anses.fr Mission Antibiorésistance Laboratoire de Sécurité des Aliments