BEUDAMED
    FDA Adverse Event Malfunction Summary report: N

    XPERT MRSA/SA BC (CE-IVD)

    MDR report key: 23842531 · Received December 18, 2025

    Report

    Report Number
    3004530258-2025-00041
    Event Type
    Malfunction
    Date Received
    December 18, 2025
    Date of Event
    November 21, 2025
    Report Date
    April 10, 2026
    Manufacturer
    CEPHEID AB
    Product Code
    NQX
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    FI
    Reporter Occupation
    501

    Narratives

    Additional Manufacturer Narrative · 0

    A DISCREPANCY WAS OBSERVED WHERE THE XPERT MRSA/SA BC ASSAY FAILED TO DETECT STAPHYLOCOCCUS AUREUS IN A BLOOD CULTURE SAMPLE THAT WAS LATER CONFIRMED AS S. AUREUS BY CULTURE AND MALDI-TOF. ALL LABORATORY PROCEDURES WERE PERFORMED ACCORDING TO THE PACKAGE INSERT, AND NO MIXED CULTURES WERE OBSERVED. ON (B)(6)2025, THE REPEAT TESTING WITH XPERT MRSA/SA BC REMAINED NEGATIVE, BUT ANALYSIS OF THE DATA SHOWS SCC CTS (STAPHYLOCOCCAL CHROMOSOMAL CASSETTE CYCLE THRESHOLD) OF 36.4, WHICH SUGGESTS THE PRESENCE OF S. AUREUS. THE OUTCOME WAS A DELAY IN COMMUNICATING THE PRESENCE OF S. AUREUS IN BLOOD CULTURE. CEPHEID'S PRELIMINARY ANALYSIS SUGGESTS THAT THIS FALSE-NEGATIVE RESULT IS LIKELY DUE TO A MUTATION IN THE SPA GENE TARGET REGION, WHICH INTERFERED WITH ASSAY DETECTION. THE CUSTOMER CONFIRMED THAT THE STRAIN WAS NOT MRSA, SO THERE WAS NO IMPACT ON PATIENT HEALTH OR ANTIBIOTIC THERAPY. THE INITIAL ANTIBIOTIC CHOICE WAS APPROPRIATE. THE CUSTOMER HAS AGREED TO SEND THE ISOLATE FOR FURTHER INVESTIGATION TO DETERMINE THE ROOT CAUSE OF THIS GENETIC VARIATION. THE INVESTIGATION IS 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, A CUSTOMER CONTACTED TECHNICAL SUPPORT TO REPORT A QUESTIONABLE NEGATIVE RESULT ON XPERT MRSA/SA BC LOT 22203/1001465376 [METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS; STAPHYLOCOCCUS AUREUS]. THE PATIENT IS A 78-YEAR-OLD INDIVIDUAL WHO WAS NOT ON ANTIBIOTICS PRIOR TO BLOOD COLLECTION. CEFUROXIME WAS STARTED ONLY AFTER POST-COLLECTION OF SAMPLES. THEIR MEDICAL HISTORY IS UNKNOWN FOR IMMUNOCOMPROMISED STATUS, DIABETES, CANCER, VASCULAR DISEASE, OR IN-DWELLING CATHETER. SAMPLE 1: ON (B)(6) 2025, THE FIRST BLOOD CULTURE SAMPLE WAS COLLECTED USING BACTEC¿ PLUS AEROBIC/F MEDIUM AND PLACED IMMEDIATELY IN AN INCUBATOR PER INSTRUCTIONS FOR USE (IFU). ON (B)(6) 2025, THE AEROBIC BOTTLE FLAGGED POSITIVE. GRAM STAIN SHOWED GRAM-POSITIVE COCCI IN CLUSTERS. CULTURES WERE SET ON CHOCOLATE AGAR, FAA, CHROMOGENIC SA-AGAR, AND ORI-AGAR; PURE COLONIES WERE OBSERVED WITH NO MIXED CULTURE. XPERT MRSA/SA BLOOD CULTURE (BC) TESTING (LOT 22203) WAS PERFORMED ACCORDING TO IFU AND YIELDED MRSA NEGATIVE AND SA NEGATIVE. ON (B)(6) 2025, SA WAS IDENTIFIED ON CHROMOGENIC SA-AGAR AND CONFIRMED BY THE BIOMÉRIEUX MALDI-TOF PLATFORM WITH AN IDENTIFICATION SCORE OF 99.9%. NO MIXED CULTURE WAS OBSERVED AND THE MORPHOLOGY WAS CONSISTENT WITH SA. ON (B)(6) 2025, THE SAME SAMPLE 1 MATERIAL STORED AT ROOM TEMPERATURE (RT) WAS RETESTED WITH XPERT MRSA/SA BC (LOT 22203) AND AGAIN YIELDED MRSA NEGATIVE AND SA NEGATIVE. BECAUSE THE SA-NEGATIVE RESULT WAS SUSPECTED TO BE DISCREPANT, THE SAMPLE 1 MATERIAL WAS TESTED WITH FILMARRAY BCID, WHICH DETECTED SA AND WAS REPORTED TO THE CLINICIAN. SAMPLE 2: ON (B)(6) 2025, THE SECOND BLOOD CULTURE SAMPLE WAS COLLECTED USING BACTEC¿ PLUS AEROBIC/F MEDIUM. AFTER THIS BLOOD COLLECTION, THE PATIENT WAS PUT ON CEFUROXIME. ON (B)(6) 2025, THE AEROBIC BOTTLE FLAGGED POSITIVE AND GRAM-POSITIVE COCCI IN CLUSTERS WERE OBSERVED. MALDI-TOF CONFIRMED SA WITH 99.9%, AND XPERT MRSA/SA TESTING WAS NOT PERFORMED BECAUSE SA HAD ALREADY BEEN ESTABLISHED. ON (B)(6) 2025, SAMPLE 2 RECONFIRMED SA FROM CHROMOGENIC SA-AGAR AND MALDI-TOF, CONSISTENT WITH A PURE CULTURE. SUSCEPTIBILITY TESTING BY DISK DIFFUSION DEMONSTRATED THAT SA WAS SENSITIVE TO ALL TESTED ANTIBIOTICS, INCLUDING CEFOXITIN, CLINDAMYCIN, RIFAMPICIN, ERYTHROMYCIN, CIPROFLOXACIN, SULFAMETHOXAZOLE/TRIMETHOPRIM, TETRACYCLINE, TOBRAMYCIN, AND FUSIDIC ACID. THE DISCREPANCY RESULTED IN A ONE-DAY DELAY IN COMMUNICATING THE SA RESULT TO THE CLINIC. THERE WAS NO IMPACT ON PATIENT. THE CUSTOMER SAW FROM THE PATIENT INFORMATION SYSTEM THAT THE PATIENT HAD BEEN TRANSFERRED TO (B)(6) HOSPITAL.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    15021 XPERT MRSA/SA BC (CE-IVD) XPERT MRSA/SA BLOOD CULTURE NQX CEPHEID AB 1001465376

    Patients

    Seq Age Sex Outcome Treatment
    1 78 YR Unknown