|
Intended use: vitek® ms is a mass spectrometry system using matrix-assisted laser desorption/ionization time of flight mass spectrometry (maldi-tof ms) for the identification of microorganisms cultured from human specimens.The vitek® ms system is a qualitative in vitro diagnostic device indicated for use in conjunction with other clinical and laboratory findings to aid in the diagnosis of bacterial, yeast and mould infections.Issue description: a customer in russia reported to biomérieux potential multiple misidentifications for three patient samples in association with the product vitek ms instrument (ref.(b)(4), serial number (b)(6) ), with knowledge base version 3.2.This complaint is related to the complaint (b)(4) (same customer, same issue, vitek ms instrument serial number (b)(6) ).Customer obtained discrepant results between vitek ms and vitek 2 with potential wrong identifications provided by vitek ms for three samples coming from three patients, tested on two instruments; the results were as follows for vitek ms instrument, serial number (b)(6): **vitek ms sn (b)(6) results : -lab id 30782526.5 no identification.2 single choice to brucella spp.1 single choice to staphylococcus hominis.-lab id 30782528.7 no identification.1 single choice to brucella spp.1 single choice to staphylococcus aureus.-lab id 30951754.1 single choice to moraxella (branhamella) catarrhalis.Other methods : - vitek = moraxella group.- gram staining = various in shape and color.Expected id: unknown, no referent identification method performed.According to biomérieux global customer service preliminary data analysis, the misidentifications are probably linked to a system limitation (species not present in the vitek ms knowledge bases).In addition, it could also be combined with a non optimal spot preparation.At the time of assessment, there is no indication or report from the customer that this event led to any adverse event related to the user/patient's state of health.An internal investigation has been initiated.
|
|
Context: a customer in russia reported to biomérieux potential multiple misidentifications for three patient samples in association with the product vitek ms instrument (ref.410895, serial number (b)(6)).Vitek ms mode : ivd kb version : 3.2 (cli) issue type: discrepant results between vitek ms and vitek2 for 3 samples coming from 3 different patients.Vitek ms sn (b)(6) results : lab id (b)(6) 5 no identification 2 single choice to brucella spp 1 single choice to staphylococcus hominis lab id (b)(6) 7 no identification 1 single choice to brucella spp 1 single choice to staphylococcus aureus lab id (b)(6) 1 single choice to moraxella (branhamella) catarrhalis other methods : -vitek2 = moraxella group -gram staining = various in shape and color expected id: unknown, no referent identification method performed culture conditions: specimen : unknown culture media : blood agar and chocolate agar (biomerieux) incubation: 24-48 hours spotting tool : plastic loop.Issue date: 07, 08, 09, 11 and 12 dec 2023.Fine tuning date before the issue: 04 and 11 dec 2023.Investigation: batch history record and complaint trend analysis** there is no capa, no non-conformity on vitek ms linked with customer's complaint.A trend analysis has been for the period from (b)(6) 2023 to (b)(6) 2023 with the error code ivd mis-identification - f871; no trend has been identified.Investigation results fine tuning according to the vilink alert tool criteria, no fine tuning was needed during the tests made.Note: good fine tuning and good calibrator spot preparation are a prerequisite for monitoring the system with vilink alert tool.Spot preparation quality the sample ¿all peaks¿ values are quite heterogeneous.Based on this finding, the spot preparation quality needs to be verified with the customer.Kb review unknown, no referent identification method performed.Sample data analysis reprocessing the customer¿s data with vitek ms kb v3.2 allows to show a high heterogeneity in term of identification results within each instrument and between both instruments.The misidentifications to brucella spp were obtained with spectra having the lowest number of peaks.When the number of peaks is just over 30, the risk to get ¿doubtful¿ results is high due to a lack of information (missing peaks, not enough peaks to eliminate candidate identification).In addition, the ¿sample all peaks¿ are quite heterogeneous, for example it varies between 53 to 111 for lab id (b)(6) on vitek ms sn (b)(6) it could be due to a non-optimal spot preparation.Reprocessing the customer¿s data with vitek ms kb v3.3 allows to eliminate all the misidentification to brucella spp.However, there is still a high heterogeneity in term of identification results within each instrument and between both instruments.Reprocessing of the data with a specific r&d identification tool allows to obtain an identification to moraxella lincolnii for a high number of tests performed.Moraxella lincolnii is not present in vitek ms ivd databases meaning that it could be a system limitation.Sequencing of the strains is needed to confirm their identifications.Based on this analysis, the misidentifications are likely linked to a system limitation (species not present in the vitek ms knowledge bases).In addition, it could also be combined with a non-optimal spot preparation.For information, the following limitations are written in the user_manual_supplements_-_161150-924_-_a_-_en_-_vitek_ms_clinical_use_-_v3.2_knowledge_base : testing of species not found in the database may result in an unidentified result or a misidentification.Brucella spp is an ¿highly pathogenic organism¿.Handle isolate with extreme caution and send it to a reference laboratory for further identification according to your laboratory¿s protocol and/or country regulations.Interpretation of results and use of the vitek ms system require a competent laboratorian who should judiciously make use of experience, specimen information, and other pertinent procedures before reporting the identification of test organisms.Additional information known to the user, such as gram stain reaction, colonial and cellular morphology, and growth aerobically or in co2 should be considered when accepting vitek ms results.¿ related to the misidentification as brucella, these incorrect organism identifications have been seen so far in conjunction with degraded spectra (linked to a non-optimal spot preparation or a non-optimal fine-tuning).Expected identification after investigation it could be moraxella lincolnii but it needs to be confirmed by sequencing.Conclusion: the most probable root causes of this issue are non-optimal spot preparation and system limitation.According to data above, there is no reconsideration of vitek ms instrument (ref.410895) performance.
|
