Catalog Number 421037 |
Device Problem
Incorrect Or Inadequate Test Results (2456)
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Patient Problem
No Patient Involvement (2645)
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Event Type
malfunction
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Event Description
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A customer in (b)(6) notified biomérieux of incorrect results associated with vitek®2 ast-n350 test kit (reference 421037).The customer reported obtaining incorrect results for a (b)(6) sample ((b)(6)).The isolate was reconstituted per (b)(6) recommendations and placed on a blood agar plate.After overnight incubation, a subculture was performed on a blood agar, the results were as follows: - piperacillin-tazobactam mic value = 16mg/l, intermediate, - ertapenem mic value= 0.25 mg/l, susceptible, - and the organism was identified as an esbl and ampc producer, no additional tests were performed to confirm the esbl positive.Expected results for this (b)(6) sample were the following: - piperacillin-tazobactam mic value >= 128mg/l, resistant, - ertapenem mic value= 4mg/l, resistant, - esbl status negative.Retesting was performed using biomérieux sheep blood agar and the customer obtained the same results.This event occurred during an external quality control test; therefore no patient results were impacted.An internal biomérieux investigation will be initiated.
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Manufacturer Narrative
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An internal biomérieux investigation was performed due to discrepant results on piperacillin/ tazobactam (tzp) and ertapenem (etp) with e.Coli neqas distribution 4214 sample # 4179 on vitek® 2 v7.01 ast-n350 card.Identification of the neqas strain was confirmed and testing included one (1) card of each customer lot 7900559403 called cl1, 7900390103 called cl2, and one (1) card of a random lot 7900428203 called rl.The broth microdilution for tzp and for etp was also performed.The reference methods (broth microdilution, bmd), which were the method used for piperacillin/ tazobactam development (formulation tzp03n) and for etp development (etp02n formulation) on ast-n350 card gave: tzp mic = 128 mg/l (r) and etp mic = 2 mg/l (r).On vitek 2 v7.01 (aes parameters: global european based + phenotypic): ast-n350 cards were tested from cba (cos bmx) subculture.One (1) card of two customer lots (7900559403 called cl1, and 7900390103 called cl2) , and one (1) card of a random lot (7900428203 called rl) were tested from cba (cos bmx) subculture.The results were the same fro all three (3) lots: tzp mic = 16 mg/l intermediate.Etp mic = 0.25 mg/l susceptible.Conclusion: the false tzp intermediate customer result was reproduced in-house.The false etp susceptible result was reproduced in-house.The biomérieux study confirms an underestimation of ertapenem.Note: the vitek 2 proposed an ampc or esbl phenotype, and the intended result by neqas was ampc , so vitek 2 proposed the correct phenotype.Quality system review of the most recent quarterly trend report, q1 2018, did not identify these complaints as systemic quality issues.
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Search Alerts/Recalls
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