(59 days)
The BD Phoenix™ Automated Microbiology System is intended 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 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 Nonand ractive 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 Piperacillin at concentrations of I this premarks normounter is to the SST only Phoenix panels. Piperacillin has been shown to 0.5-120 pg miro against most strains of microorganisms listed below, as described in the FDA-approved package insert for this antimicrobial agent.
The BD Phoenix Automated Microbiology System (Phoenix System) is an automated system for the rapid identification (ID) and antimicrobial susceptibility testing (AST) of clinically relevant bacterial isolates. The system includes the following components:
- BD Phoenix instrument and software. .
- BD Phoenix panels containing biochemicals for organism ID testing and antimicrobial agents . for AST determinations.
- BD Phoenix ID Broth used for performing ID tests and preparing AST Broth inoculum. .
- BD Phoenix AST Broth used for performing AST tests only. .
- 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 reagents. Organisms for susceptibility testing must be a pure culture and preliminarily identified as a gram-negative or gram-positive isolate. For each isolate, an inoculation equivalent to a 0.5 McFarland standard 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 of an antimicrobial agent. Measurements of changes to the indicator as well as bacterial turbidity are used in the determination Macterial 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°C. The instrument takes readings of the panels every 20 minutes. The readings are interpreted to give an identification of the isolate, minimum inhibitory concentration (MIC) values and category interpretations, S, I, or R (sensitive, intermediate, or resistant).
The provided text describes the acceptance criteria and study results for the BD Phoenix™ Automated Microbiology System with Piperacillin 0.5-128 µg/mL.
Here's a breakdown of the requested information:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Defined by FDA Guidance Document) | Reported Device Performance (BD Phoenix™ System) |
|---|---|
| Site Reproducibility: | |
| Overall intra-site reproducibility > 90% | Overall intra-site reproducibility > 90% |
| Overall inter-site reproducibility > 95% | Overall inter-site reproducibility > 95% |
| Clinical Performance: | |
| Essential Agreement (EA) | 94.3% (n=1781) |
| Category Agreement (CA) | 93.8% (n=1701) |
2. Sample Sizes Used for the Test Set and Data Provenance
- Test Set Sample Size:
- Site Reproducibility: A panel of gram-negative isolates (specific number not given, but tested in triplicate on three different days).
- Clinical Studies: 1781 isolates for Essential Agreement (EA) and 1701 for Category Agreement (CA).
- Data Provenance: Clinical, stock, and challenge isolates were tested across multiple geographically diverse sites across the United States. This indicates a prospective study design using diverse US data.
3. 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 or qualifications of experts used to establish the ground truth. The ground truth was established by the NCCLS reference broth microdilution method.
4. Adjudication Method for the Test Set
The document does not describe an adjudication method for disagreements. The Phoenix System results were directly compared to the NCCLS reference method.
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
This is not applicable. The BD Phoenix™ Automated Microbiology System is an automated system for antimicrobial susceptibility testing, not an imaging device or AI assistant that improves human reader performance.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, a standalone performance evaluation was conducted. The performance of the BD Phoenix™ Automated Microbiology System (device only) was compared directly to the NCCLS reference broth microdilution method for both site reproducibility and clinical studies. There is no mention of a human-in-the-loop component in the evaluation of the system's performance.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
The ground truth used was the NCCLS reference broth microdilution method (AST panels prepared according to NCCLS M7). This is considered a gold standard or reference method in antimicrobial susceptibility testing.
8. The Sample Size for the Training Set
The document does not explicitly state a "training set" sample size. The description pertains to the validation of the device's performance against a reference method. It's an automated system, and the "training" (if any, in a machine learning sense) would have occurred during the development of the system itself, prior to this validation study.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as a distinct "training set" with ground truth establishment for this specific submission is not described. The study focuses on the validation of the automated system against a established reference method.
§ 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.”