A customer in (b)(6) notified biomérieux of obtaining a discrepant minimum inhibitory concentration (mic) result for a qc strain of streptococcus pneumoniae in association with the etest® benzylpenicil pg 32 ww s30 strips (reference 412265, lot 1007061670).The customer obtained a mic between 0.5-1 with the expected result mic=4.Oxacillin disc diffusion was also performed and had no zone of inhibition.As there is no patient associated with this quality control strain, there is no adverse event related to any patient's state of health.The etest instructions for use (ifu) state the mic interpretation ranges (g/ml) for benzlpenicilin etest when tested with streptococcus pneumoniae are: susceptible: less than or equal to 0.06.Intermediate: 0.12-1.Resistant: greater than or equal to 2.Per the ranges in the ifu, the customer obtained an intermediate result, mic between 0.5-1 when the expected result was resistant, mic=4.Biomérieux will initiate an internal investigation.
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Biomerieux initiated an internal investigation in response to a discrepant minimum inhibitory concentration (mic) result for a qc strain of streptococcus pneumoniae in association with the etest® benzylpenicil pg 32 ww s30 strips (reference 412265, lot 1007061670).Identification testing was performed on the submitted isolate and confirmed to be streptococcus pneumoniae on vitek ms v3 (knowledge base v3.2).Biomeriuex's investigation included the following: testing of customer lot 1007061670and internal reference lot 1007477180 against atcc® quality control strains.Testing the customer submitted qc isolate against the broth micro dilution (bmd reference method.Testing the submitted isolates using customer lot 1007061670and and internal reference lot 1007477180 using both the eucast and clsi breakpoints 2019.All atcc® strains obtained conforming results for both the etest customer lot and the reference lot.Bmd was performed on the streptococcus pneumoniae survey strain, both the clsi and eucast methodologies were tested in parallel.Both the clsi and eucast methodologies obtained a mic=1 mg/l interpreted as susceptible and intermediate per the clsi and eucast respective breakpoints.The streptococcus pneumoniae survey strain was tested with the etest pg 32 customer lot 1007061670 and reference lot 1007477180.Both lots obtained a result of mic=1mg/l.The result interpretations of mic=1 are intermediate per the eucast 2019 breakpoints, and susceptible according to clsi 2019 breakpoints.The etest pg 32 mic values for the streptococcus pneumoniae survey strain are within essential agreement with the bmd reference method result.The survey strain expected result was not reproduced with etest product reference 412265 nor the reference method (bmd).The etest pg32 strip is performing as expected.
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