Biomérieux conducted an internal investigation: this investigation was initiated due to a discrepancy between etest® etp 32 (ertapenem) reference 531600 blister, result of susceptible(s) obtained by the customer and the expected result by the neqas survey resistant(r/i ).The strain is an enterobacter cloacae complex neqas # (b)(4).During identification testing, testing confirmed result of enterobacter cloacae on vitek® 2 gn card.Clsi 2017 breakpoints enterobacteriaceae -ertapenem [ s less than or equal to 0.5 - 1 - greater than or equal to 2 r ].Eucast 2017 breakpoints enterobacteriaceae -ertapenem [ s less than or equal to 0.5 - > 1 r ].· reference method used for etest® development: agar dilution (ad) : etp mic = 0.5 mg/l : s.· reference method recommended by neqas : broth microdilution (bmd) : etp mic = 1 mg/l : i.· mechanism of resistance detection: pcr imp, oxa48 like, kpc, ndm and vim negative (essay msast-465).·a reproducibility study was performed on etest®.All qc strains were conform (pseudomonas aeruginosa atcc 27853, escherichia coli atcc 25922, staphylococcus aureus atcc 29213, enterococcus faecalis atcc 29212, bacteroides fragilis atcc 25285, streptococcus pneumoniae atcc 49619, haemophilus influenzae atcc 49766) and the neqas strain gave mic equal to 0.5 mg/l s.Biomérieux reproduced the customer results of susceptible (s).Etest® etp (mic 0.5 ¿g/ml s) is an essential agreement with the reference mic 0.5 mg/l obtained with agar dilution (method used for the development of etest etp strip ) , without category error.Etest® etp strip performed as intended, and no further action is required.The broth microdilution which is the method used by neqas, was also performed.It gave an etp mic equal to 1 mg/l i.This result is in the middle of the clsi breakpoints, so within 1 doubling dilution the category can be s or r.
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