(80 days)
The MicroScan® Synergies plus™ Gram-Negative MIC/Combo Panel is used to determine quantitative and/or qualitative antimicrobial agent susceptibility of colonies grown on solid media of rapidly growing aerobic and facultative anaerobic gram-negative bacilli. After inoculation, panels are incubated for 4.5 - 18 hours at 35℃ +/- 1℃, in a WalkAway SI or equivalent, and read by the MicroScan® Instrumentation. Additionally, the panels may be incubated in a non-CO2 incubator and the AST portions can be read visually, according to the Package Insert.
This particular submission is for the addition of the antimicrobial Cefazolin, at concentrations of 0.5 to 32 ug/ml, to the test panel.
The gram-negative organisms which may be used for Cefazolin susceptibility testing in this panel are:
Escherichia coli Klebsiella spp. Proteus mirabilis
The MicroScan® Synergies plus" Gram-Negative Panels with Cefazolin is not intended for use with:
- Klebsiella oxytoca Enterobacter spp. Citrobacter freundii Morganella morganii Proteus vulgaris
Proteus penneri Providencia spp Serratia spp Yersinia enterolitica
MicroScan® Synergies plus™ Gram-Negative MIC/Combo Panels, utilizing both the MicroScan® Rapid Fluorogenic Identification and Dried Overnight Antimicrobial Susceptibility Testing (AST) technologies, are designed for use in determining quantitative and/or qualitative antimicrobial agent susceptibility of colonies grown on solid media of rapidly growing aerobic and facultative anaerobic gram-negative bacilli.
The antimicrobial susceptibility tests are miniaturizations of the broth dilution susceptibility test that have been diluted in Mueller-Hinton Broth and dehydrated. Various antimicrobial agents are diluted in broth to concentrations bridging the range of clinical interest. Panels are rehydrated with water, after inoculation with a standardized suspension of the organism. After incubation in the WalkAway® S7 System or equivalent for 4.5 - 18 hours, the minimum inhibitory concentration (MIC) for the test organism is read by determining the lowest antimicrobial concentration showing inhibition of growth.
The MicroScan® Synergies plus™ Gram-Negative MIC/Combo Panels with Cefazolin are designed to determine antimicrobial agent susceptibility. The device's performance was compared to an NCCLS frozen Reference Panel.
Here's a breakdown of the acceptance criteria and the study details:
1. Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Essential Agreement) | Reported Device Performance (Cefazolin) |
|---|---|
| >97% Essential Agreement | >97% Essential Agreement |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document mentions "fresh and stock Efficacy isolates and stock Challenge strains" but does not specify the exact number of samples used for the external evaluation.
- Data Provenance: The document does not explicitly state the country of origin. The study was a "external evaluation." It utilized both "fresh and stock Efficacy isolates" (implying a mix of recent clinical samples and archived ones) and "stock Challenge strains" (controlled, known strains). This suggests a mixed approach, potentially incorporating both retrospective and prospective elements for the "efficacy isolates" and a controlled retrospective aspect for the "challenge strains."
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
The document does not provide information on the number of experts or their qualifications. The "Expected Results" for the Challenge strains were determined prior to the evaluation, which implies expert consensus or adherence to established standards, but explicit details are not given.
4. Adjudication Method for the Test Set
The document does not explicitly state an adjudication method. It compares the device's performance to an "NCCLS frozen Reference panel" and "Expected Results" for challenge strains. This suggests the reference panel and expected results served as the "ground truth" against which the device was evaluated, rather than an adjudication process between different readers or methods.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. This study focuses on the performance of the automated system against a reference method, not on human reader improvement with or without AI assistance.
6. Standalone Performance Study
Yes, a standalone study was done. The document describes the "external evaluation" where the MicroScan® Synergies plus™ Gram-Negative MIC/Combo Panel's performance was compared directly with an NCCLS frozen Reference Panel and Expected Results for challenge strains. This is a standalone evaluation of the algorithm/device's performance.
7. Type of Ground Truth Used
The ground truth used was primarily a reference standard: an "NCCLS frozen Reference panel" for efficacy isolates and "Expected Results" for challenge strains. The NCCLS (National Committee for Clinical Laboratory Standards, now Clinical and Laboratory Standards Institute - CLSI) sets recognized standards for antimicrobial susceptibility testing, making their reference panel a strong gold standard.
8. Sample Size for the Training Set
The document does not specify a separate training set or its sample size. The description focuses on the evaluation of the device's performance after its development. It's likely that proprietary data was used for developing and training the underlying algorithms, but these details are not provided in the 510(k) summary.
9. How the Ground Truth for the Training Set Was Established
The document does not provide information on how the ground truth for any potential training set was established.
§ 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).