BEUDAMED
    FDA Adverse Event Malfunction Summary report: N

    XPERT MRSA/SA BC (CE-IVD)

    MDR report key: 23853604 · Received December 19, 2025

    Report

    Report Number
    3004530258-2025-00042
    Event Type
    Malfunction
    Date Received
    December 19, 2025
    Date of Event
    November 21, 2025
    Report Date
    March 18, 2026
    Manufacturer
    CEPHEID AB
    Product Code
    NQX
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    IS
    Reporter Occupation
    OTHER HEALTH CARE PROFESSIONAL
    Health Professional
    Yes

    Narratives

    Additional Manufacturer Narrative · 0

    THE CUSTOMER REPORTED A DISCREPANCY INVOLVING THE XPERT MRSA/SA BLOOD CULTURE ASSAY. BOTH THE INITIAL AND REPEAT TESTS PERFORMED ON A BLOOD CULTURE SAMPLE AND ON PURE COLONIES YIELDED MRSA NEGATIVE; SA NEGATIVE, WITH ONLY MECA POSITIVE. HOWEVER, STANDARD CULTURE AND SUSCEPTIBILITY TESTING IDENTIFIED METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS (MRSA), CONFIRMED BY OXACILLIN RESISTANCE ON MULLER HINTON AGAR. THE PURE COLONY SAMPLE WAS TESTED OFF-LABEL. THE DISCREPANCY LIKELY REFLECTS A RARE MRSA STRAIN WITH MUTATIONS IN: - SPA GENE (CEPHEID S. AUREUS ID TARGET). - SCCMEC/ORFX JUNCTION REGION (TARGET LINKING MECA TO S. AUREUS CHROMOSOME). ALTERNATIVELY, THE ISOLATE COULD REPRESENT A SPA VARIANT BORSA, AND THE MECA COULD BE CARRIED BY A COAGULASE-NEGATIVE STAPHYLOCOCCUS ALSO PRESENT IN THE BLOOD CULTURE. DESPITE THE MOLECULAR TEST DISCREPANCY, THE PATIENT RECEIVED APPROPRIATE ANTIBIOTIC THERAPY WITHIN FOUR HOURS OF THE PCR RESULT, AND TREATMENT WAS NOT DELAYED. THE PATIENT DIED ONE WEEK LATER, BUT THE DEATH WAS NOT ATTRIBUTED TO THE TEST DISCREPANCY. THE LATEST WAS CONFIRMED BY CUSTOMER THROUGH DISTRIBUTOR VIA EMAIL. THE CUSTOMER HAS SENT THE SAMPLE FOR SEQUENCING TO THE NATIONAL S. AUREUS LABORATORY OF THE MINISTRY OF HEALTH BUT DID NOT SHARE THE RESULTS. HOWEVER, CEPHEID DID RECEIVE THE SAMPLE AND PERFORMED SEQUENCING. THE INVESTIGATION CONFIRMED THE ISOLATE AS MRSA (ST45, SPA TYPE T1081, SCCMEC V). GENOMIC ANALYSIS IDENTIFIED TWO RARE ALTERATIONS: A 148 BASE PAIRS (BP) DELETION IN THE SPA GENE, WHICH DISRUPTS BINDING OF THE ASSAY'S SPA PRIMERS, AND INSERTED GENETIC ELEMENTS BETWEEN ORFX AND THE SCCMEC V CASSETTE, WHICH INTERFERE WITH SCC TARGET AMPLIFICATION. EACH OF THESE MUTATIONS HAS BEEN REPORTED PREVIOUSLY (FOR EXAMPLE SPA TYPE T1081/ST45 HAS BEEN REPORTED IN AUSTRALIA, PROMPTING CEPHEID TO UPDATE THEXPERT MRSA/SA BC TEST), BUT NOT IN COMBINATION. TOGETHER, THEY PREVENTED DETECTION OF BOTH SPA AND SCC TARGETS, LEAVING MECA AS THE SOLE DETECTED MARKER AND PREVENTING INTERVENTION BY THE RULES BASED ALGORITHM. OVERALL, THE DISCREPANT RESULT WAS ATTRIBUTABLE TO RARE GENOMIC ALTERATIONS WITHIN AN ST45 MRSA LINEAGE. CEPHEID CONSIDERS THIS ROOT CAUSE A MALFUNCTION. THEREFORE, THIS CASE IS DEEMED REPORTABLE. ANNEX CODES HAVE BEEN UPDATED TO REFLECT THE OUTCOME OF THE INVESTIGATION.

    Additional Manufacturer Narrative · 0

    THE INVESTIGATION IS STILL ONGOING.ADDITIONAL INFORMATION REGARDING LIKELY ROOT CAUSE WILL BE PROVIDED IN A FOLLOW UP REPORT ONCE THE INVESTIGATION HAS BEEN COMPLETED.

    Description of Event or Problem · 0

    ON (B)(6) 2025, CUSTOMER REPORTED A DISCREPANCY TO CEPHEID REGARDING XPERT MRSA/SA BC (METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS / STAPHYLOCOCCUS AUREUS BLOOD CULTURE) LOT 22203/1001465376. ON (B)(6) 2025, A BLOOD CULTURE SAMPLE WAS COLLECTED USING BACTEC PLUS AEROBIC/F CULTURE VIALS. THE AEROBIC BOTTLE WAS INCUBATED AND FLAGGED POSITIVE ON (B)(6) 2025 AT 05:25 AM AFTER 15 HOURS AND 5 MINUTES. A GRAM STAIN WAS PERFORMED AT 08:56 AM ON THE SAME DAY, SHOWING GRAM-POSITIVE COCCI IN CLUSTERS. TWO TESTS USING XPERT MRSA/SA BC LOT 22203 WERE CONDUCTED ON (B)(6) 2025, GAVE THE FOLLOWING RESULTS: SA NEGATIVE, MRSA NEGATIVE, AND THESE RESULTS WERE COMMUNICATED TO THE PHYSICIAN. A FOLLOW UP TEST USING XPERT MRSA/SA BC LOT 22203 WAS CONDUCTED OF PURE COLONIES GROWN ON CHROM MRSA. AND THE RESULT WAS AGAIN SA NEGATIVE AND MRSA NEGATIVE, REPORTED TO THE PHYSICIAN. THIS TEST CONDUCTED OF PURE COLONIES IS CONSIDERED OFF-LABEL DUE TO THE SAMPLE TYPE AND COLLECTION DEVICE. ANTIMICROBIAL SUSCEPTIBILITY TESTING (AST) WAS PERFORMED ON MULLER HINTON AGAR PLATES, SHOWING RESISTANCE TO OXACILLIN, INDICATING MRSA. THIS SUSCEPTIBILITY RESULT WAS REPORTED TO THE PHYSICIAN. THE INCORRECT RESULTS OBTAINED THROUGH XPERT MRSA/SA BC WERE THEREFORE CONTRADICTORY TO THE SUSCEPTIBILITY FINDINGS. THE BLOOD CULTURE SAMPLE WAS STORED AT ROOM TEMPERATURE BETWEEN (B)(6) 2025 AT 10:26:32 AM AND (B)(6) 2025 AT 10:02:38 AM. DESPITE THE MOLECULAR TEST DISCREPANCY, THE PATIENT RECEIVED APPROPRIATE ANTIBIOTIC THERAPY WITHIN FOUR HOURS OF THE PCR RESULT, AND TREATMENT WAS NOT DELAYED. THE PATIENT DIED ONE WEEK LATER, BUT THE DEATH WAS NOT ATTRIBUTED TO THE TEST DISCREPANCY. THE LATEST WAS CONFIRMED BY CUSTOMER THROUGH DISTRIBUTOR VIA EMAIL.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    2242418 XPERT MRSA/SA BC (CE-IVD) XPERT MRSA/SA BLOOD CULTURE NQX CEPHEID AB 1001465376

    Patients

    Seq Age Sex Outcome Treatment
    1 78 YR Male