(37 days)
The BD Phoenix™ Automated Microbiology System is intended for in vitro quantitative determination of antimicrobial susceptibility by minimal inhibitory concentration (MIC) of most gram-negative aerobic and facultative anaerobic bacteria isolates from pure culture for Enterobacteriaceae and Non-Enterobacteriaceae and most gram-positive bacteria isolates from pure culture belonging to the genera Staphylococcus and Enterococcus.
This premarket notification is for the addition of the antimicrobial agent aztreonam at concentrations of 0.5-64 ug/mL to gram-negative ID/AST or AST only Phoenix panels. Aztreonam has been shown to be active in vitro against most strains of microorganisms listed below, as described in the FDA-approved package insert for this antimicrobial agent.
Active In Vitro and in Clinical Infections Against:
Citrobacter species (including C. freundii) Enterobacter species (including E. cloacae) Escherichia coli Klebsiella oxytoca
Klebsiella pneumoniae Proteus mirabilis Serratia species (including S. marcescens)
Active In Vitro Against:
Aeromonas hydrophila Morganella morganii Pasteurella multocida Proteus vulgaris
Providencia stuartii Providencia rettgeri Yersinia enterocolitica
The BD Phoenix Automated Microbiology System (Phoenix System) is an automated system for the rapid identification and in vitro antimicrobial susceptibility testing of isolates from pure culture of most aerobic and facultative anaerobic gram-negative and gram-positive bacteria of human origin. The system includes the following components:
- BD Phoenix instrument and software. .
- DD Phoenix maudinent and between cals for organism ID testing and antimicrobial agents t for AST determinations.
- for AD Coternmantene .
- BD Phoenix AST Broth used for performing AST tests only. .
- DD Fhoonix AST Drom
BD Phoenix AST Indicator solution added to the AST Broth to aid in bacterial growth . determination.
The Phoenix panel is a sealed and self-inoculating molded polystyrene tray with 136 micro-wells containing dried reagens. Organisms for susception is solate. For each isolate, an inoculation premimarily (defirmed as a gratis candard is prepared in Phoenix ID Broth.
The Phoenix AST method is a broth based microdilution test. The Phoenix System utilizes a redox indicator for the detection of organism growth in the presence withing on wood in the de inclicator for the detection of organism grown in the proseiled unbidty are used in the clotenination Measurements of changes to the mulcator as welr as ouctory of bacterial growth. Each AST panel configuration contains several antimicrobial agents with a wide range of two-fold doubling dilution concentrations.
The instrument houses the panels where they are continuously incubated at a nominal temperature of 35 %. The mstullient takes readings of the panels of copy concentration (MIC) values and category interpretations, S, I, or R (sensitive, intermediate, or resistant).
Here's a summary of the acceptance criteria and the study that proves the BD Phoenix™ Automated Microbiology System meets them for aztreonam, based on the provided text:
Acceptance Criteria and Reported Device Performance
| Acceptance Criterion | Reported Device Performance (Aztreonam) |
|---|---|
| Essential Agreement (EA) | 96.2% |
| Category Agreement (CA) | 96.2% |
| Intra-site reproducibility | Greater than 95% |
| Inter-site reproducibility | Greater than 95% |
Study Details
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Sample sizes used for the test set and data provenance:
- Test set size: 1470 isolates (as indicated by 'n' for both EA and CA in Table 1).
- Data provenance: Clinical, stock, and challenge isolates were tested across multiple geographically diverse sites across the United States. This indicates a retrospective and prospective mixture of data (stock and challenge isolates can be considered pre-defined/retrospective, while clinical isolates would be prospectively collected from patient samples).
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Number of experts used to establish the ground truth for the test set and qualifications of those experts:
- The document does not specify the number of experts or their qualifications for establishing ground truth. The ground truth method involved comparison to the NCCLS reference broth microdilution method and expected results for challenge isolates.
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Adjudication method for the test set:
- The document does not explicitly describe an adjudication method for disagreements between the BD Phoenix system and the reference method. The performance metrics (EA and CA) are calculated based on agreement/disagreement with the reference method.
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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, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. This study is for an automated microbiology system, which replaces human interpretation in the final reading of MIC values and categorical interpretations, rather than assisting human readers. The comparison is against a reference laboratory method (NCCLS broth microdilution), not human readers.
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If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes, this study is a standalone performance study of the BD Phoenix™ Automated Microbiology System. The Phoenix System is an automated system providing quantitative MIC values and categorical interpretations (S, I, or R) without human intervention in the interpretation process once the panel is loaded and reading begins. The results are compared directly to a "reference method."
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- For clinical isolates, the ground truth was the NCCLS reference broth microdilution method.
- For challenge isolates, the ground truth was expected results.
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The sample size for the training set:
- The document does not specify the sample size for a training set. The descriptions focus on the performance evaluation against the reference method. The device is a system that utilizes a redox indicator and optical density readings, with its algorithms likely developed and validated previously, and this submission focuses on adding a new antimicrobial agent.
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How the ground truth for the training set was established:
- The document does not provide information on how the ground truth for a training set was established. Given the nature of a 510(k) for adding an antimicrobial agent to an existing system, the focus is on the performance of the new agent, not on the fundamental development of the system's core algorithms.
§ 866.1645 Fully automated short-term incubation cycle antimicrobial susceptibility system.
(a)
Identification. A fully automated short-term incubation cycle antimicrobial susceptibility system is a device that incorporates concentrations of antimicrobial agents into a system for the purpose of determining in vitro susceptibility of bacterial pathogens isolated from clinical specimens. Test results obtained from short-term (less than 16 hours) incubation are used to determine the antimicrobial agent of choice to treat bacterial diseases.(b)
Classification. Class II (special controls). The special control for this device is FDA's guidance document entitled “Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA.”