(50 days)
MB/BacT Blood Culture Bottles in combination with the MB/BacT Enrichment Fluid are specifically designed for the cultivation of Mycobacterium sp. commonly isolated from blood when used in conjunction with the MB/BacT Mycobacterial Detection System.
MB/BacT Blood Culture Bottles are specifically designed for the cultivation of Mycobacterium sp. Commonly isolated from blood.
Here's an analysis of the provided text regarding the MB/BacT™ Blood Culture Bottle's acceptance criteria and supporting study:
The document is a 510(k) Premarket Notification for the MB/BacT™ Blood Culture Bottle, which is designed for the recovery and detection of Mycobacteria from blood. The device is being compared to the predicate device, the BACTEC 13A Blood Bottle (K863191).
Acceptance Criteria and Device Performance
The document doesn't explicitly state quantitative acceptance criteria in a pass/fail format. Instead, it focuses on demonstrating substantial equivalence to the predicate device. The performance is gauged by whether the MB/BacT bottles yield comparable results to the BACTEC 13A.
Here's a table summarizing the reported device performance in relation to the predicate device:
| Aspect | Acceptance Criteria (Implied for Substantial Equivalence) | Reported Device Performance (MB/BacT™ Blood Culture Bottle) |
|---|---|---|
| Intended Use | To be equivalent to the predicate device for recovery and detection of Mycobacteria from blood. | Same intended use: recovery and detection of Mycobacteria from blood. |
| Specimen Source | To be equivalent to the predicate device in handling blood specimens. | Blood |
| Sample Volume | To be equivalent to the predicate device's sample volume. | 5 mls. |
| Microbial Growth | Favorable growth performance for mycobacterial isolates comparable to the predicate device. | Non-clinical: Favorable growth performance achieved with 20 mycobacterial isolates (10 species) at 1x10² and 1x10¹ CFU. Clinical: 55 organisms isolated by both bottles, 9 isolated by MB/BacT only, 2 isolated by BacTec 13A only. This demonstrates comparable or potentially superior isolation rates for MB/BacT for some organisms. |
| Safety and Effectiveness | To be as safe and effective as the legally marketed predicate device. | Conclusions state the device is as safe, as effective, and performed as well or better than the legally marketed device, based on comparable test results in clinical and in-house studies. |
Study Details
2. Sample size used for the test set and the data provenance:
- Non-clinical (In-house) Test Set: 20 mycobacterial isolates representing 10 different species.
- Clinical Test Set: 238 paired bottles.
- Data Provenance: Not explicitly stated, but the submission is from the United States (Organon Teknika Corporation, Durham, North Carolina). Given the nature of a 510(k) submission, it would typically involve prospective or retrospective data collected under a controlled study protocol. The phrase "Two clinical studies were carried out" suggests a prospective design for the clinical evaluation.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The document does not specify the number of experts used or their qualifications for establishing ground truth. The determination of "organism isolation" would typically be performed by trained laboratory personnel, but no explicit details on expert involvement are provided.
4. Adjudication method for the test set:
- The document does not describe an explicit adjudication method. The outcome is presented as isolated organisms by either device or both. It implies that the presence of a Mycobacteria species would be confirmed by standard laboratory identification methods once detected by either bottle, but no specific adjudication process for discrepancies is detailed.
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:
- No. This device is a blood culture bottle for detecting microbial growth, not an AI-assisted diagnostic imaging or interpretation tool. Therefore, an MRMC comparative effectiveness study involving human readers and AI assistance is not applicable and was not performed.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done:
- Yes, in essence. The performance of the MB/BacT™ Blood Culture Bottle (which operates using a colorimetric sensor to monitor CO₂ production) is inherently standalone in its detection mechanism. The study directly compares the detection capability of this bottle technology to the predicate BACTEC 13A technology, without explicitly involving varying human interpretations of the growth signals from the device itself. The "organism isolation" is the direct output of the bottle's function.
7. The type of ground truth used:
- Microbial Growth/Identification: The ground truth is the actual isolation and identification of Mycobacterium sp. from the blood samples. This would typically be confirmed by subsequent laboratory procedures (e.g., staining, culturing on specific media, biochemical tests, or molecular methods) after a "positive" signal from the blood culture bottle.
8. The sample size for the training set:
- The document does not mention a separate training set. This type of device (a diagnostic culture medium) doesn't typically involve a "training set" in the machine learning sense. Its performance is evaluated based on its ability to support microbial growth and detect metabolic byproducts.
9. How the ground truth for the training set was established:
- As no training set is mentioned in the context of machine learning, this question is not applicable. The device's mechanism of action (colorimetric detection of CO2) is based on established biological principles, not on
learned patterns from a training dataset.
§ 866.2560 Microbial growth monitor.
(a)
Identification. A microbial growth monitor is a device intended for medical purposes that measures the concentration of bacteria suspended in a liquid medium by measuring changes in light scattering properties, optical density, electrical impedance, or by making direct bacterial counts. The device aids in the diagnosis of disease caused by pathogenic microorganisms.(b)
Classification. Class I. With the exception of automated blood culturing system devices that are used in testing for bacteria, fungi, and other microorganisms in blood and other normally sterile body fluids, this device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter.