Biomérieux conducted an internal investigation: the samples in question are rectal samples from three (3) patients and the growth observed was of typical purple colonies of enterococcus faecium van b.The identification was confirmed using mass spectromety and the identification was enterococcus faecium.Using ast vitek 2 p606, pcr multiplex expert and microdilution testing, determined that the strains were susceptible to vancomycin.The customer reported that testing was performed with media from an atcc strain e.Faecalis 29212 and the results passed.The customer reported that the product was stored correctly at 2-8°c and the instructions for use were followed.The customer provided three (3) impacted patient strains for the investigation.A review of device history record for this lot was performed and no discrepancy or anomaly was observed during this review.Biomérieux retains samples of every lot number released to the market.The retained sample plates for lot number 1006583800, that were manufactured at various different times (06h37, 06h45, 08h15, 08h23, 09h50) were tested in order to verify the microbiological performance of the product.A reference lot number was also tested in parallel 1006606660, expiry 24-sept-2018.The testing was performed in accordance with the quality control protocol.The following controls were tested: enterococcus faecalis atcc 51299, enterococcus faecium atcc 700221, enterococcus faecium 3-229 scv, enterococcus faecalis atcc 29212, escherichia coli atcc 25922, staphylococcus aureus atcc 25923, candida tropicalis atcc 9968, klebsiella oxytoca 9009075, pediococcus pentosaceus 07 11 603 and enterococcus gallinarum 0502053.In addition, a strain of enterococcus faecium 35667 susceptible to vancomycin was also tested.The following results were obtained on the impacted lot number and on the reference lot number: good growth of characteristic colonies for vancomycin resistant enterococcus faecalis and enterococcus faecium after 24 hours and 48 hours of incubation.Total inhibition of vancomycin susceptible enterococcus after 48 hours of incubation.Total inhibition of the gram negative and gram positive bacteria tested after 48 hours of incubation.Partial inhibition of candida tropicalis after 48 hours of incubation.All the quality control results obtained are in accordance with the expected specifications.Biomérieux could not confirm the customer's complaint with the retained sample plates.Analysis of the patient strains provided by the customer: strain number 1, strain number 2, and strain number 3.The following tests were performed on the strains: identification of the strains.Gram testing.Antibiotic susceptibility testing.Enzymatic testing.The patient strains you provided were tested in accordance with protocol on the retained biomérieux sample plates for lot number 1006673260, reference 43004, expiry 22-oct-2018.It was not possible to test the strains on the impacted lot number 1006583800 as it had already expired at the time of testing.The following results were obtained: identification of the strains was performed using the vitek® ms and the vitek® 2: strain number 1: enterococcus faecalis, this result was confirmed by repeat testing.Strain number 2: enterococcus faecium.Strain number 3: enterococcus faecium.Gram testing: strain 1, 2, 3; gram positive cocci.Antibiotic susceptibility testing: strain 1, 2, 3; susceptible to vancomycin.Enzymatic testing: strain 1, 2, 3; catalase negative.Total inhibition of the three patient strains after 48 hours of incubation was observed on biomérieux sample plates, lot number 1006673260, reference 43004.The issue observed; false positive results on chromid¿ vre agar, reference 43004, was not confirmed on the three patient strains provided by the customer for the investigation.Our investigation did not reproduce the false positive results; therefore it was not possible to determine the root cause of the issue.It is important to note that this media must be correctly stored and must not be exposed to light other than during the inoculation and reading steps.The package insert states "store the plates in their box at 2-8°c until the expiry date.If not in the box, plates can be stored for 2 weeks at 2-8°c in the cellophane sachet in the dark.The medium must not be exposed to light other than during the inoculation and reading steps.".
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