|
Investigation: the patient was a 4-year-old female.On (b)(6) 2024, a positive blood culture sample was tested on the biofire bcid2 panel.The biofire bcid2 panel reported s.Aureus and staphylococcus spp.As detected.The biofire bcid2 panel was positive for s.Aureus, staphylococcus spp., and meca/c but negative for mrej, resulting in a not detected result for 'meca/c and mrej (mrsa).' note that the biofire bcid2 panel will only report a detected result for 'meca/c and mrej (mrsa)' if s.Aureus, mrej, and meca/c assays are all positive.Penicillin-binding protein 2a (pbp2a) antigen testing was performed on s.Aureus isolated from culture.Gram stain showed gram positive cocci.Three different antimicrobial susceptibility testing (ast) methods were used (sensititer, oxacillin etest, and cefoxitin disk diffusion) and they all confirmed the isolate as mrsa.The blood culture sample was also tested with the bd max and cepheid mrsa pcr assays and both tests confirmed mrsa.The patient impact due to the biofire bcid2 panel is unknown as patient information was not provided.No serious injury or death was reported.Quality control (qc) records for biofire bcid2 panel pouch lot# 31hb23 (kit lot# 2422323) were reviewed.This pouch lot passed qc criteria and was found within specifications.The filmarray instrument (serial number# (b)(6) ) was working within designed specifications.Biofire's investigation into this event is ongoing and further information has been requested from the customer.The full investigation and associated conclusions will be provided in the final report.No remedial action, corrective action, preventive action, or fsca has been deemed necessary at this time.Conclusion: investigation ongoing.
|
|
Summary: (b)(6) medical center reported a potential false negative methicillin-resistant staphylococcus aureus (mrsa) result on the biofire blood culture identification 2 (bcid2) panel after testing a patient's blood culture sample.The patient impact due to the biofire bcid2 panel result is unknown as the customer did not provide patient information.Biofire has requested further information from the customer and is currently investigating this event.No remedial action, corrective action, preventive action, or field safety corrective action (fsca) has been deemed necessary at this time.
|
|
Investigation: the patient was a 4-year-old female.On (b)(6) 2024, a positive blood culture sample was tested on the biofire bcid2 panel.The biofire bcid2 panel reported s.Aureus and staphylococcus spp.As detected.The biofire bcid2 panel was positive for s.Aureus, staphylococcus spp., and meca/c but negative for mrej, resulting in a not detected result for 'meca/c and mrej (mrsa).' note that the biofire bcid2 panel will only report a detected result for 'meca/c and mrej (mrsa)' if s.Aureus, mrej, and meca/c assays are all positive.Penicillin-binding protein 2a (pbp2a) antigen testing was performed on s.Aureus isolated from culture.Gram stain showed gram positive cocci.Three different antimicrobial susceptibility testing (ast) methods were used (sensititer, oxacillin etest, and cefoxitin disk diffusion) and they all confirmed the isolate as mrsa.The blood culture sample was also tested with the bd max and cepheid mrsa pcr assays and both tests confirmed mrsa.The patient impact due to the biofire bcid2 panel is unknown as patient information was not provided.No serious injury or death was reported.Quality control (qc) records for biofire bcid2 panel pouch lot# 31hb23 (kit lot# 2422323) were reviewed.This pouch lot passed qc criteria and was found within specifications.The filmarray instrument (serial number# (b)(6)) was working within designed specifications.Conclusion: the investigation concluded that the most likely cause for the false negative result was 1) pouch anomaly or 2) a possible mrej strain with reduced reactivity.1) as stated under the "interpretation of results" section of the biofire bcid2 panel instructions for use (ifu) (www.Online-ifu.Com/iti0048), the biofire software evaluates dna melt curves for each well of the pcr2 array to determine if a pcr product was present in that well.If the melt profile indicates the presence of a pcr product, then the analysis software calculates the melting temperature (tm) of the curve and compares it against the expected tm range for the assay.If the software determines that the tm falls inside the assay-specific tm range, the melt curve is called positive.If the software determines that the melt curve is not in the appropriate tm range, the melt curve is called negative.In some instances, as seen in the run file provided by the customer, a pouch anomaly can shift the temperatures and amplicon melts outside of the designated melt range/window, resulting in an unexpected negative detection.Biofire is continuously monitoring the manufacturing process and has controls in place to ensure the product is manufactured to the highest quality.Each biofire reagent lot is qualified prior to product release; this qualification includes a high statistical-confidence sampling to confirm that the kit components released for customer use are conforming.All qc metrics for the pouch lot and instrument were met, and they passed qc.Review of the associated instrument run files showed the instrument was performing within specification and is not suspected to have contributed to the discrepancy observed by the customer.Overall, the mrej assay on the biofire bcid2 panel has a false negative failure rate of <0.001 in the field over the last year.These rates are within the biofire system specifications.2) through bd max and cepheid comparator testing the customer had detected mrsa in the patient sample.This would indicate the possibility of an mrej type that is detected less efficiently by the biofire bcid2 panel, present in the sample.During analytical testing, the biofire bcid2 panel assays were assessed via a combination of in silico analysis of sequences available in public databases along with testing of over 450 isolates representing the genetic, geographic, and temporal diversity of species, subspecies, and amr gene types detected by the panel.Please refer to table 118, "results for meca/c and mrej (mrsa) in staphylococcus aureus isolates tested and predicted reactivity for mrej types" in the biofire bcid2 panel ifu.Here is listed specific mrej subtypes that are not expected to be detected by the biofire bcid2 panel.For example, a subset of mrej type ix sequences (2/8) have mismatches to the assay primer(s) that may have an impact on detection.Additionally, there are mrej types and variant sequences identified that may be amplified less efficiently or may not be detected such as mrej types xv, xviii, and xix.Per the biofire bcid2 panel ifu, antimicrobial resistance can occur via multiple mechanisms.A not detected result for a genetic marker of antimicrobial resistance does not indicate susceptibility to associated antimicrobial drugs or drug classes.A detected result for a genetic marker of antimicrobial resistance cannot be definitively linked to the microorganism(s) detected.Culture is required to obtain isolates for antimicrobial susceptibility testing, and biofire bcid2 panel results should be used in conjunction with culture results for the determination of susceptibility or resistance.According to table 65 biofire bcid2 panel clinical performance summary, meca/c and mrej (mrsa) of the biofire bcid2 panel ifu, the performance of the meca/c and the mrej assays compared to commercially available fda-cleared and ce-marked molecular ivd assays performed on positive blood cultures showed an overall positive percent agreement of 91.9% (95% ci 82.5-96.5%) and an overall negative percent agreement of 98.0% (95% ci 92.9-99.4%).Archived testing was not performed for meca/c and mrej (mrsa).Isolates recovered from the five false negatives specimens were identified as mssa by soc phenotypic ast methods.Isolates recovered from the two false positive specimens were identified as mrsa by soc phenotypic ast methods.
|
