(98 days)
InTray GC is used, like conventional Thayer-Martin media plates, to grow Neisseria gonomhoeae and similar organisms.
The InTray GC contains a Modified Thayer-Martin (MTM) medium within a sealed inner well. It has a two inch diameter well and 5-6ml of media. The inner seal that covers this well also covers another sealed cavity containing a CO2 generating tablet. There is also an outer adhesive label seal with a window that does not fog up under 100% relative humidity. The user opens and reseals this outer label. In practice, when the user opens the outer seal, he may then remove and discard the inner seal exposing the surface of the medium and the sealed cavity. The next step is to inoculate the surface of the medium with the patient sample. Next, puncture the seal over the cavity with any convenient sharp point. Finally, reseal the outer label over the InTray. High humidity within the InTray causes the tablet to generate CO2. Incubate the InTray and observe the growth of organisms through the window without opening the InTray and therefore without disturbing the atmosphere. Observation can be by eye, hand lens or microscope. This packaging has been used since 1994 for other BioMed media products.
The provided text describes a 510(k) premarket approval for the BioMed Diagnostics Incorporated's InTray GC for the isolation of pathogenic Neisseria. The submission details both laboratory and clinical studies to demonstrate its performance.
Here's an analysis of the acceptance criteria and study details based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The text does not explicitly state pre-defined acceptance criteria in terms of numerical thresholds for sensitivity, specificity, or colony counts. However, the study aims to demonstrate that InTray GC performs comparably to or better than existing commercial media. The implicit acceptance criteria appear to be:
| Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|
| Laboratory Study: | |
| Ability to recover N. gonorrhoeae | - For two N. gonorrhoeae strains, recovered colony counts were comparable to fresh commercially prepared media. |
- For the other two N. gonorrhoeae strains, colony counts were about half compared to fresh commercial media.
- In no case was there failure to recover the organism. |
| Suppression of competing organisms (e.g., N. sicca, E. coli, S. epidermidis, P. mirabilis, C. albicans) | - After one year at room temperature, the InTray GC was superior to fresh commercial media in suppressing growth of these organisms. |
| Shelf life | - Demonstrated performance after "one year at room temperature." (Superior in suppressing contaminants after one year at room temperature. Implied adequate for N. gonorrhoeae recovery after one year as well, as tested.) |
| Clinical Study: | |
| Agreement with commercially prepared media for N. gonorrhoeae detection | - Results positive for N. gonorrhoeae were identical to those for commercially prepared media: 18 positive, 210 negative. |
| Reduction of contaminants (clinical samples) | - The principal contaminant was C. albicans. - 17 positive for the InTray GC (for C. albicans)
- 30 positive with the comparison MTM medium (for C. albicans).
- This indicates superiority of InTray GC in suppressing C. albicans in a clinical setting. |
| Safety (no adverse indications) | - There were no adverse indications in these tests. |
2. Sample Size Used for the Test Set and Data Provenance
-
Laboratory Study:
- Test Set Organisms: Pure cultures of four strains of N. gonorrhoeae (including NCCLS standard strain and an AHU auxotype) and several competing organisms (N. sicca, E. coli, S. epidermidis, P. mirabilis, C. albicans).
- Sample Size: Not explicitly stated as a number of distinct samples for each culture, but described as tests performed using "pure cultures at 10^2 cfu for each of four strains of N. gonorrhoeae and at 10^5 cfu for competing organisms." It also mentions "two one-year studies." This implies multiple tests over time for each organism.
- Data Provenance: The N. gonorrhoeae strains were drawn from a "world-wide data base." The study was performed "in the laboratory."
- Retrospective/Prospective: The laboratory studies sound prospective in design, carefully controlled experiments designed to test the media's performance over one year.
-
Clinical Study:
- Test Set Sample Size: 228 female patients.
- Data Provenance: Clinical study using cervical swabs. The country of origin is not specified, but typically for 510(k) submissions, clinical data is often from the US or a region with comparable medical standards.
- Retrospective/Prospective: This was a prospective clinical study, comparing the InTray GC to commercially prepared media.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not provide details about experts for establishing ground truth in the traditional sense of consensus or adjudication for image-based or diagnostic interpretation.
- For the laboratory study, the "ground truth" for organism identification and colony counts would have been established by standard microbiological methods, likely performed by trained microbiologists.
- For the clinical study, the "ground truth" for N. gonorrhoeae positivity and the presence of C. albicans would have been established by the comparison to "commercially prepared media," which serves as the reference standard in this context. It's implied that clinical laboratory personnel would have read these results, but their qualifications are not specified.
4. Adjudication Method for the Test Set
Not applicable. This device is a culture medium, and the "ground truth" is determined by the growth or non-growth of specific organisms, not by interpretive reads that would require adjudication among experts. The comparison is directly to a reference method (commercial media).
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
Not applicable. This is not an AI-assisted diagnostic device, nor is it an imaging device requiring human reader interpretation in the context of an MRMC study. It's a culture medium.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
Not applicable. This device is a culture medium, not an algorithm. Its performance is inherent to the medium itself.
7. The Type of Ground Truth Used
- Laboratory Study: Microbiological culture standards (known pure cultures at specific CFUs), and comparison to fresh commercial MTM and chocolate media.
- Clinical Study: Comparison to "commercially prepared media" (presumably reference MTM or other standard culture methods for N. gonorrhoeae). The results were compared for agreement on positive and negative cases.
8. The Sample Size for the Training Set
Not applicable. This is not a machine learning or AI device that requires a distinct training set. The "training" for such a product would be its development and formulation, not data feeding to an algorithm.
9. How the Ground Truth for the Training Set was Established
Not applicable, as there is no "training set" in the context of an AI/ML algorithm.
§ 866.2410 Culture medium for pathogenic
Neisseria spp.(a)
Identification. A culture medium for pathogenicNeisseria spp. is a device that consists primarily of liquid or solid biological materials used to cultivate and identify pathogenicNeisseria spp. The identification aids in the diagnosis of disease caused by bacteria belonging to the genusNeisseria, such as epidemic cerebrospinal meningitis, other meningococcal disease, and gonorrhea, and also provides epidemiological information on these microorganisms.(b)
Classification. Class II (performance standards).