(22 days)
The Cepheid Xpert™ MRSA/SA Blood Culture Assay performed on the GeneXpert® Dx System™ is a qualitative in vitro diagnostic test intended for the detection of Staphylococcus aureus (SA) and methicillin-resistant Staphylococcus aureus (MRSA) DNA directly from patient positive blood cultures. The assay utilizes automated real-time polymerase chain reaction (PCR) for the amplification of MRSA/SA specific DNA targets and fluorogenic target-specific hybridization probes for the real-time detection of the amplified DNA. The assay is performed directly on positive blood culture specimens using BD BACTEC™ Plus Aerobic/F blood culture bottles that are determined as Gram Positive Cocci in Clusters (GPCC) or as Gram Positive Cocci in singles (GPC) by Gram stain. The Xpert MRSA/SA Blood Culture Assay is indicated for use in conjunction with other laboratory tests, such as culture, and clinical data available to the clinician as an aid in the detection of MRSA/SA from patient positive blood cultures. Subculturing of positive blood cultures is necessary to recover organisms for susceptibility testing or for epidemiological typing. The Cepheid Xpert™ MRSA/SA Blood Culture Assay is not intended to monitor treatment for MRSA/SA infections.
When an MRSA negative/SA positive result is obtained, the result should be interpreted as "MRSA indeterminate/SA Positive, antimicrobial susceptibility testing pending". Further testing should be performed using an FDA-cleared, phenotypic antimicrobial susceptibility testing method on isolated colonies recovered from the blood culture bottle. MRSA positive results should be reported as such.
The Cepheid Xpert® MRSA/SA Blood Culture Assay (Xpert MRSA/SA Blood Culture Assay) is a rapid, automated DNA test for simultaneously detecting MRSA and SA directly from positive blood culture specimens. The assay is performed on the Cepheid GeneXpert Dx System.
This summary is based on the provided text, which refers to a 510(k) submission for a device modification rather than a new study. Therefore, the information typically associated with a new study's acceptance criteria and performance data is not fully present. The document explicitly states that the device is "substantially equivalent" to a previously cleared predicate device and that "the only changes that have been made to the new device are to the package insert, as directed by the agency." This means there wasn't a new clinical study to establish performance against acceptance criteria for this specific submission.
However, I can extract the relevant information regarding the equivalence claim and the device itself.
1. Table of Acceptance Criteria and Reported Device Performance
Since this 510(k) is for a modification (package insert changes) to an already cleared device, there are no new acceptance criteria or device performance metrics presented in this document. The device's performance is implicit in its substantial equivalence to the predicate device, which would have undergone its own performance evaluation.
| Performance Metric | Acceptance Criteria (from a new study) | Reported Device Performance (from a new study) |
|---|---|---|
| N/A | There are no new performance metrics or associated acceptance criteria presented in this 510(k) submission as the changes are limited to the package insert and the device is deemed substantially equivalent to a predicate. | There is no new performance data presented for this specific 510(k) submission. Performance is based on the previously cleared predicate device (K082140). |
2. Sample Size Used for the Test Set and Data Provenance
Not applicable for this 510(k) submission as no new performance study was conducted. The document focuses on the substantial equivalence of the modified device to its predicate, primarily due to labeling changes.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
Not applicable for this 510(k) submission as no new performance study was conducted.
4. Adjudication Method for the Test Set
Not applicable for this 510(k) submission as no new performance study was conducted.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not done for this 510(k) submission. The document explicitly states that the changes are related to the package insert, and the device is substantially equivalent to a predicate.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
The device itself is an automated DNA test ("Nucleic Acid Amplification Test, DNA, Methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus (SA), qualitative") performed on the Cepheid GeneXpert Dx System. Therefore, it inherently operates in a standalone manner (algorithm only) to detect MRSA/SA DNA. However, this specific 510(k) is not presenting a new standalone performance study, but rather confirming the substantial equivalence of a modified version of an already cleared standalone device. The device's intended use also states that it's "indicated for use in conjunction with other laboratory tests, such as culture, and clinical data available to the clinician." This implies that while the algorithm provides a result, clinical interpretation involves other human-generated data.
7. The Type of Ground Truth Used
Not explicitly stated in this document for this specific submission as no new performance testing was conducted. For the predicate device, the ground truth for detecting MRSA/SA from positive blood cultures would typically be established through microbiology culture and subsequent identification and susceptibility testing (e.g., phenotypic methods) of the isolated organisms.
8. The Sample Size for the Training Set
Not applicable for this 510(k) submission as no new training was performed for a device modification involving only package insert changes.
9. How the Ground Truth for the Training Set Was Established
Not applicable for this 510(k) submission as no new training was performed.
§ 866.1640 Antimicrobial susceptibility test powder.
(a)
Identification. An antimicrobial susceptibility test powder is a device that consists of an antimicrobial drug powder packaged in vials in specified amounts and intended for use in clinical laboratories for determining in vitro susceptibility of bacterial pathogens to these therapeutic agents. Test results are used to determine the antimicrobial agent of choice in the treatment of bacterial diseases.(b)
Classification. Class II (performance standards).