An internal investigation was performed for a misidentification of a enterococcus gallinarum survey sample (cqe ecbu 2018-3a prospective biology 11.1646 ) as enterococcus faecium in association with the api® 20 strep test strip.A review of the customer results with different lots of api 20 strep showed good identification or very good identification to enterococcus faecium with a note: "possibility of enterococcus gallinarum or enterococcus casseliflavus if vanco r." as a susceptible result was obtained.With vancomycin disc the result was enterococcus faecium.The instructions for use states, "limitations of the method: the api 20 strep system is intended uniquely for the identification of those species included in the database (see identification table at the end of this package insert).It cannot be used to identify any other microorganisms or to exclude their presence".Identification of the customer's strain was confirmed as enterococcus gallinarum on vitek ms.The strain was not retested on api 20 strep since the customer's identification corresponds to the expected result with the knowledge base and the package insert.As explained in package insert, for perform quality control with the a api 20 strep, the following two strains should be tested: streptococcus equi spp zooepidemicus atcc 700400 and streptococcus uberis 700407.The prospective biology report stated: "this strain exhibits a natural chromosomal resistance to vancomycin encoded by the van c gene, which is often of a low level." that's probably why you had difficulty to detect the resistance with the disc of vancomycin.Conclusion: the identification of the strain received was confirmed to enterococcus gallinarum by vitek ms.Customer result is compliant with the knowledge base and the limitations.Api 20 strep strip perfromed as expected.
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