A customer in (b)(6) reported the occurrence of false susceptible flucytosine result (mic = 4¿g/ml) for candida norvegensis eeq biologie proficiency sample in association with the vitek® 2 ast-ys07 test kit.An internal biomérieux investigation was performed that included testing for both fluconazole (flu) and flucytosine (fct) results on vitek® 2 ast-ys07 cards with a strain of candida norvegensis from the biologie prospective survey (mycology 2017- sample 3a).Id testing : identification was confirmed to candida norvegensis on yst card (lot 2430356103) ast testing: · reference method to determine the intended result for fluconazole and flucytosine: broth microdilution, method used to develop the formularies "flu01n" / "fct01n" (in ast-ys07 card).· flu mic = 16 mg/l intermediate · fct mic = 8 mg/l intermediate interpretation according to vitek 2 breakpoints in v7.01 : fda 2009 breakpoints for candida / fluconazole s =8 - i 16-32 - r >/=64.Fda 2012 breakpoints for candida / flucytosine : s =4 - i 8-16 - r >/=32.Note: for antifungals, essential agreement between vitek® 2 card and reference method mics is +/- 2 doubling dilutions.· products & system incriminated: -*ast -ys07 on vitek 2 v7.01 three (3) vitek 2 ast-ys07 card lots were tested from sabouraud dextrose agar (sda).Vitek 2 gave the following results: **flu mic = 16 mg/l i on the three (3) lots tested **fct mic = 4 mg/l s on two (2) lots , 8 mg/l i on the third lot.The vitek 2 results are within essential agreement with the reference mic within +/- 1 doubling dilution.Note: according to fsca 2509 (released april 2015), fct results from ast-ys07 cards (fct01n formulation) should not be reported for any organism.Conclusion: -we duplicated the customer results on ast-ys07 cards (mic flu=16 mg/l i and fct mic=4 mg/l s).-]the vitek 2 ast-ys07 cards perform as intended.The vitek 2 values are within essential agreement with the reference results obtained in bmd.-the reference mic for both fluconazole and flucytosine are in the middle of the breakpoints, so the strain can be susceptible or resistant within +/- 2 doubling dilutions.-->borderline strain.
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