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510(k) Data Aggregation
(331 days)
The BACTEC ® MYCO/F LYTIC Culture vial when used with the BACTEC 9000MB System is a qualitative test for the culture and recovery of mycobacteria in human blood speciments from patients who are suspected of having septicemia.
BACTEC MYCO/F LYTIC blood culture medium is a non-selective growth medium intended for the culture and recovery of mycobacteria and designed for blood volumes of one to five mL. BACTEC MYCO/F LYTIC culture medium is a Middlebrook 7H9 and Brain Heart Infiusion broth formulation with specific formulation modifications made to enhance the growth of mycobacteria. It is used specifically with the BACTEC 9000MB instrument in the monitoring of clinical blood specimens for the presence of microorganisms. This medium contains the same fluorescence senor as the BACTEC MYCO/F Sputa culture medium and detection is based on changes in oxygen concentration in the vial resulting from metabolism and growth of microorganisms. The sensor is monitored by the BACTEC 9000MB System for increasing fluorescence which is proportinal to the decrease in oxygen. A positive determination indicates the presumptive presence of viable microorganisms in the vial.
Here's an analysis of the acceptance criteria and study details for the BACTEC MYCO/F LYTIC Culture Medium, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly define formal "acceptance criteria" with specific thresholds (e.g., "sensitivity must be >X%"). However, it implies acceptance criteria by comparing the performance of the BACTEC MYCO/F LYTIC medium to a predicate device (BACTEC 13A) and by reporting internal performance characteristics.
The implied objective is that the BACTEC MYCO/F LYTIC medium should be at least comparable to, or ideally better than, the predicate device in terms of mycobacteria recovery and detection, with acceptable false positive and false negative rates.
Since explicit acceptance criteria are missing as numerical targets, I will present the key performance metrics reported in the studies.
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance (BACTEC MYCO/F LYTIC) |
|---|---|---|
| Clinical Recovery (Overall) | Comparable or improved recovery of pathogenic mycobacteria compared to BACTEC 13A. | Total 39 pathogenic mycobacterial isolates recovered. |
| 5 (13%) recovered ONLY in BACTEC MYCO/F LYTIC. | ||
| 2 (5%) recovered ONLY by BACTEC 13A. | ||
| 32 recovered by both. | ||
| Clinical Recovery (Species-specific) | Demonstrate recovery of various pathogenic mycobacteria species. | Mycobacterium avium: 3/30 recovered only by MYCO/F LYTIC, 1/30 only by 13A, 26 by both. |
| Mycobacterium tuberculosis: 6/6 recovered by both. | ||
| Mycobacterium kansasii: 2/3 recovered only by MYCO/F LYTIC, 1/3 only by 13A. | ||
| Internal Recovery (Species Diversity) | Detect a variety of mycobacteria species as positive. | Detected: M. tuberculosis, M. kansasii, M. fortuitum, M. intracellulare, M. bovis, M. terrae, M. simiae, M gordonae, M. celatum, M. abscessus, M. maimoense. |
| Unsatisfactory recovery: M. xenopi and M. szulgai. | ||
| False Positive Rate | Acceptably low false positive rate. (No explicit numerical threshold given, but generally, lower is better). | 0.4% (1 out of 284 blood specimens). |
| For instrument positive MYCO/F LYTIC vials: 2.6% (1 out of 38). (Note: 16 false positives out of 28 overfilled vials were excluded from the study due to protocol deviation). | ||
| False Negative Rate | Acceptably low false negative rate. (No explicit numerical threshold given). | 0% (Based on terminal subcultures of 50% of negative vials). |
| Contamination Rate | Acceptably low contamination rate. (No explicit numerical threshold given). | 0.9% |
| Time to Detection (Internal Study) | General indication of detection within a reasonable timeframe (implied, not explicitly quantified as a criterion for clinical relevance). | Varies by species and blood volume. Examples: M. tuberculosis avg 22.9 days (1 mL), 18.7 (3 mL), 17.3 (5 mL). M. avium avg 8.0-8.1 days. M. fortuitum avg 8.0-5.1 days. (See Table 2 for full details). |
2. Sample Size and Data Provenance
- Clinical Test Set Sample Size: 284 blood specimens.
- Data Provenance: Prospective clinical study conducted at "two clinical sites considered large tertiary care teaching hospitals in geographically diverse areas." The specific country of origin is not mentioned but typically for FDA submissions of this era, the studies would be conducted in the United States.
3. Number of Experts and Qualifications for Ground Truth
The document does not explicitly state the number of experts or their specific qualifications for establishing the "ground truth" (e.g., "smear and/or subculture-negative/positive") for the clinical test set. It mentions "microbiological workup" and validation against "smear and/or subculture." This implies standard laboratory practices performed by qualified laboratory personnel, but details on expertise (e.g., years of experience, specific certifications) are absent.
4. Adjudication Method
The document does not describe an explicit adjudication method (like 2+1 or 3+1) for resolving discrepancies in the ground truth for the clinical test set. The ground truth ("smear and/or subculture-negative/positive") appears to be determined by confirmed laboratory results.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not conducted. This study compares a device (the BACTEC MYCO/F LYTIC medium) directly against a predicate device (BACTEC 13A medium) in a clinical evaluation, but it is not a "human reader" study; it's a comparison of culture media performance. Therefore, an effect size of human readers improving with or without AI assistance is not applicable.
6. Standalone (Algorithm Only) Performance Study
Yes, a standalone performance study was conducted. The "INTERNAL PERFORMANCE" section and "Table 2: Detection of Mycobacteria in the Myco/F Lytic Medium" represent a standalone evaluation. This study assessed the recovery and time to detection of various mycobacteria species at different CFU levels specifically with the BACTEC MYCO/F LYTIC medium and the BACTEC 9000MB instrument, without direct comparison to human reading or other media as the primary objective.
7. Type of Ground Truth Used
- Clinical Study: The ground truth for the clinical performance evaluation was established through laboratory confirmation (smear and/or subculture results). This represents definitive microbiological results, which would fall under a form of "pathology" in a broader sense of laboratory diagnostics.
- Internal Study: The ground truth for the internal performance study (Table 2) was based on known mycobacteria strains and quantified CFU/bottle (Colony Forming Units per bottle), with the outcome being the time to detection by the BACTEC 9000MB instrument.
8. Sample Size for the Training Set
The document does not mention a training set for the BACTEC MYCO/F LYTIC culture medium. This type of device (a culture medium for microbial growth detection) does not typically involve machine learning algorithms that require explicit "training sets" in the conventional sense. The "internal performance" study (Table 2) could be considered an initial validation or characterization of the medium's performance with known isolates under controlled conditions, serving a similar purpose to testing the device's inherent capabilities before clinical evaluation.
9. How the Ground Truth for the Training Set Was Established
Since there is no explicit mention of a "training set" in the context of machine learning, this question is not directly applicable. If the "internal performance" study is considered a foundational or characterization study, the ground truth was established by using known, cultured mycobacteria strains with quantified concentrations (CFU/bottle).
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