(92 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 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 Meropenem at concentrations of 0.5-16 ug/mL to Gram Positive ID/AST or AST only Phoenix panels. Meropenem 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 Against:
Staphylococcus aureus (B-lactamase and non-ß-lactamase producing)
Staphylococcus epidermidis (B-lactamase and non-B-lactamase producing)
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 or 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 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°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).
Acceptance Criteria and Device Performance Study for BD Phoenix™ Automated Microbiology System – Meropenem
This document summarizes the acceptance criteria and the study demonstrating the performance of the BD Phoenix™ Automated Microbiology System for Meropenem, as presented in the provided 510(k) summary.
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for the BD Phoenix™ Automated Microbiology System when compared to the NCCLS reference broth microdilution method are based on Essential Agreement (EA) and Category Agreement (CA). While specific numerical thresholds for acceptance criteria are not explicitly stated as "acceptance criteria" in the provided text, the study results are presented against the FDA's guidance document for substantial equivalence. Historically, for AST devices, typical acceptance criteria for EA and CA are often >90%.
| Performance Metric | Acceptance Criteria (Implied by FDA Guidance/Historical Norms) | Reported Device Performance (Meropenem, Gram-Positive Organisms) | Result |
|---|---|---|---|
| Essential Agreement (EA) | >90% (often >95%) | 98.4% | Met |
| Category Agreement (CA) | >90% (often >95%) | 96.0% | Met |
| Intra-site Reproducibility | >90% | >90% | Met |
| Inter-site Reproducibility | >95% | >95% | Met |
Note: The reported "concentration" and other fields in the provided table (Table 1) were largely unreadable due to formatting issues in the input. The focus here is on the EA and CA percentages.
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: The exact number of isolates for the clinical and stock/challenge sets is not explicitly stated in numerical form. However, the study involved a "panel of gram-positive isolates" for reproducibility and "Clinical, stock and challenge isolates" for performance assessment. Table 1 indicates an 'n' value for EA (though obscured by text, it appears to be around "OZL" which is not a standard numerical representation, but likely a placeholder for a count of isolates).
- Data Provenance: The clinical studies were conducted "across multiple geographically diverse sites across the United States." The data includes "stock and challenge isolates" and "clinical isolates." This indicates a mix of prospectively collected clinical samples and curated challenge strains, originating from the United States.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
The document does not mention the use of "experts" in the traditional sense for establishing ground truth. Instead, the ground truth for the test set was established by the NCCLS reference broth microdilution method. This is a standardized laboratory method, not dependent on individual expert interpretation for each case. Therefore, the concept of "number of experts" and their "qualifications" is not directly applicable in this context.
4. Adjudication Method for the Test Set
The concept of an "adjudication method" (like 2+1 or 3+1) is not applicable here because the ground truth was established by a reference laboratory method (NCCLS broth microdilution), not by a panel of human experts whose disagreements would require adjudication. The Phoenix System results were directly compared to these reference results.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, an MRMC comparative effectiveness study was not conducted. This device is an automated system for antimicrobial susceptibility testing, not an imaging or diagnostic aid that humans interpret. Therefore, the effect size of how much human readers improve with AI vs. without AI assistance is not relevant to this type of device. The comparison is between the automated system's output and a reference laboratory method.
6. Standalone Performance Study
Yes, a standalone performance study was done. The entire evaluation focuses on the performance of the "BD Phoenix™ Automated Microbiology System" (the algorithm/device only) in comparison to the NCCLS reference method. There is no human-in-the-loop component described for the system's operation or interpretation during the performance comparison. The instrument takes readings and interprets them to provide MIC values and categorical interpretations (S, I, R).
7. Type of Ground Truth Used
The type of ground truth used was a reference laboratory method: the NCCLS (National Committee for Clinical Laboratory Standards) reference broth microdilution method.
8. Sample Size for the Training Set
The document does not explicitly state the sample size used for the training set. The descriptions provided relate to the performance evaluation (test set) rather than the development or training of the system.
9. How the Ground Truth for the Training Set Was Established
The document does not explicitly describe how the ground truth for the training set was established. Given the nature of AST devices, it is highly likely that similar reference laboratory methods (like NCCLS broth microdilution) would have been used during the development and calibration of the Phoenix system to establish the expected antimicrobial susceptibility patterns for various organisms against different agents. However, this is inferred, not explicitly stated in the provided text.
§ 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.”