A customer from (b)(6) notified biomérieux of misidentification results for two patient isolates of enterococcus faecium when testing with the vitek® 2 gp id test kit (ref 21342).Vitek 2 identified the organism as enterococcus gallinarum.However, the organism had grown on chromid® vre media with purple color.When tested with vitek ms, the customer obtained an identification of enterococcus faecium.The customer states that the final identification of the organisms is enterococcus faecium.The customer reported that there was no incorrect treatment provided nor any patient injury or harm due to this discrepant result.A biomérieux internal investigation will be initiated.
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A customer from (b)(6) notified biomérieux of misidentification results for two (2) patient isolates of enterococcus faecium when testing with the vitek® 2 gp id test kit (ref 21342).Vitek 2 identified the organism as enterococcus gallinarum.However, the organism had grown on chromid® vre media with purple color.When tested with vitek® ms, the customer obtained an identification of enterococcus faecium.The customer indicated the final identification of the organisms was enterococcus faecium.An internal biomérieux investigation was performed.Two (2) gram positive isolates were submitted for vitek 2 evaluation because the vitek 2 gp card identified both as enterococcus gallinarum.However, vitek ms identified both as enterococcus faecium.The misidentification was obtained on two (2) gp card lots (2420464203 and 2420476103).The organisms were subbed, and testing included both the two (2) customer card lots and a random lot of gp cards, run in duplicate.Vitek ms was also performed.Isolate 911611 (3028): all gp cards tested gave an acceptable id (85%) of e.Faecium.Vitek ms also gave an identification of e.Faecium, with a 99.9% confidence level.Isolate 911612 (4683): four (4) gp cards tested gave a low discrimination of e.Durans/ e.Faecium.Two (2) gp cards gave a good id (89%) of e.Faecium.Vitek ms gave an identification of e.Faecium, with a 99.9% confidence level.Since e.Faecium is given as a possible identification on the four (4) cards with the low discrimination call, and the remaining two (2) cards gave an identification of e.Faecium; therefore, card and vitek ms results are in agreement.A comparison of the customer's card reaction results for e.Gallinarum against expected reaction results for e.Faecium showed two (2) atypical positive reactions (draf, bgurr) that led to the incorrect call.An increased number of atypical positive reactions can indicate contamination, mixed culture, use of non-recommended media, user set up errors, or an atypical strain.Vitek 2 gp id cards are performing as expected and no further action is necessary.
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