(73 days)
The MicroScan Dried 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 16 - 20 hours at 35°C +/ - 1°C in a non-CO2 incubator, and read either visually or with MicroScan instrumentation, according to the Package Insert.
This particular submission is for the antimicrobial ciprofloxacin (Cp-S) at concentrations of 0.004 to 8 µg/ mL to the test panel.
The gram-negative organism which may be used for ciprofloxacin susceptibility testing on this panel is:
Salmonella Typhi
MicroScan Dried Gram-Neqative MIC/Combo Panels 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 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 a non-CO2 incubator for 16-20 hours, the minimum inhibitory concentration (MIC) for the test organism is read by determining the lowest antimicrobial concentration showing inhibition of growth.
Here's a summary of the acceptance criteria and the study details for the MicroScan Dried Gram-Negative MIC/Combo Panels with Ciprofloxacin-S based on the provided FDA 510(k) summary:
Device: MicroScan Dried Gram-Negative MIC/Combo Panels with Ciprofloxacin-S (0.004 - 8 µg/mL)
Intended Use: 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. Specifically, this submission is for the antimicrobial ciprofloxacin (Cp-S) at concentrations of 0.004 to 8 µg/mL for the organism Salmonella Typhi.
1. Table of Acceptance Criteria and Reported Device Performance
The provided document does not explicitly state numerical acceptance criteria for "Essential Agreement" in a formal table format with specific thresholds. However, it indicates that the device demonstrated "acceptable performance" and details the "Essential Agreement" obtained.
| Criterion Type | Acceptance Criteria (Implicit from "acceptable performance") | Reported Device Performance (for Ciprofloxacin-S and Salmonella Typhi) |
|---|---|---|
| Essential Agreement | Acceptable performance when compared with a CLSI frozen Reference Panel, as defined in "Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA", dated August 28, 2009. | 100% Essential Agreement |
| Reproducibility & Precision | Acceptable reproducibility and precision for ciprofloxacin across different inoculum methods and instruments. | Demonstrated acceptable reproducibility and precision. |
| Quality Control | Acceptable results for ciprofloxacin in quality control testing. | Demonstrated acceptable results. |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Organism: The specific organism mentioned for testing in this submission is Salmonella Typhi. The document refers to "stock Challenge strains" for the external evaluation.
- Sample Size: The document does not specify the exact number of Salmonella Typhi isolates or challenges strains used in the test set. It mentions "external evaluation was conducted with stock Challenge strains."
- Data Provenance: Not explicitly stated (e.g., country of origin, retrospective/prospective). However, the use of "stock Challenge strains" implies a controlled laboratory setting, which is typical for in vitro diagnostic device evaluations.
3. Number of Experts and Qualifications for Ground Truth
- The document does not mention the use of human experts to establish ground truth for the test set.
- Ground Truth Method: The ground truth for antimicrobial susceptibility testing (in vitro diagnostic devices) is typically established by using a CLSI frozen Reference Panel. This standardized method eliminates the need for human expert consensus on individual results because the reference method itself serves as the gold standard for comparison.
4. Adjudication Method for the Test Set
- Not applicable as the ground truth is established by a standardized reference method (CLSI frozen Reference Panel), not by human expert review requiring adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No, an MRMC study was not conducted. This type of study (AI assistance for human readers) is not relevant for an in vitro diagnostic device like an antimicrobial susceptibility test panel, which determines susceptibility directly. The device itself is the primary determinant of the result, not an aid to human interpretation of images or complex data as seen in AI imaging applications.
6. Standalone (Algorithm Only) Performance
- Yes, a standalone performance evaluation was done. The entire study described is a standalone evaluation of the device's ability to accurately determine antimicrobial susceptibility concentrations when compared against a recognized reference method (CLSI frozen Reference Panel). The "Essential Agreement" reported is a measure of this standalone performance.
7. Type of Ground Truth Used
- CLSI frozen Reference Panel: This is the established "gold standard" reference method for antimicrobial susceptibility testing, providing the ground truth for comparison.
8. Sample Size for the Training Set
- The document does not specify a separate training set or its sample size. For in vitro diagnostic devices based on chemical reactions (like MIC panels), there isn't typically a "training set" in the machine learning sense. The device's performance is inherently based on its chemical design and manufacturing, which is validated through performance studies as described.
9. How the Ground Truth for the Training Set was Established
- Not applicable, as there is no mention of a traditional "training set" and its ground truth in the context of this device. The development of such panels relies on established microbiological principles and validated manufacturing processes to ensure the correct antimicrobial concentrations are present in each well.
§ 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).