(54 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-Enteriaceae and most Gram-positive bacteria isolates from pure culture belonging to the genera Staphylococcus, Enterococcus, and Streptococcus.
This premarket notification is for the addition of the antimicrobial agent ertapenem at concentrations of 0.25-32 ug/mL to Gram-negative ID/AST or AST only Phoenix panels. Erapenem 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:
Escherichia coli
Klebsiella pneumoniae
Active In Vitro:
Citrobacter freundii
Citrobacter koseri
Enterobacter aerogenes
Enterobacter cloacae
Klebsiella oxytoca
Morganella morganii
Proteus mirabilis
Proteus vulgaris
Providencia rettgeri
Providencia stuartii
Serratia marcescens
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. Phoenix panels are inoculated with a specified organism density and placed into the instrument.
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).
Here's a breakdown of the acceptance criteria and study information based on the provided text, adapted as if it were for an AI device for clarity in a modern context.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criterion | Target Performance | Reported Device Performance (BD Phoenix™ System) |
|---|---|---|
| Site Reproducibility (Intra-site) | >90% | >90% |
| Site Reproducibility (Inter-site) | >95% | >95% |
| Essential Agreement (EA) | Not explicitly stated in percentage | Achieved (compared to CLSI reference method) |
| Category Agreement (CA) | Not explicitly stated in percentage | Achieved (compared to CLSI reference method) |
| Accuracy (Overall for Ertapenem) | Not explicitly stated in percentage | Demonstrated (compared to CLSI reference method) |
| Reproducibility (Overall for Ertapenem) | ≥95% within ±1 dilution | 95% or greater within ±1 dilution |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: The document indicates that "Clinical, stock and challenge isolates were tested." However, specific numerical sample sizes for each type of isolate are not provided in the summary.
- Data Provenance: The data was collected from "multiple geographically diverse sites across the United States." The study used a combination of:
- Clinical isolates: Presumably prospective as they represent real-world samples.
- Stock isolates: Likely retrospective or pre-existing lab strains.
- Challenge isolates: Likely retrospective or pre-existing, used for specific performance verification against known results.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not mention the use of experts to establish ground truth for the test set. Instead, the ground truth was established by:
- CLSI reference broth microdilution method: This is a standardized, established laboratory method, not reliant on individual expert interpretation for each case.
- Expected results for Challenge set isolates: These "expected results" would be pre-determined values for known strains, which could have been established by consensus or by previous rigorous testing using reference methods.
4. Adjudication Method for the Test Set
No explicit adjudication method (e.g., 2+1, 3+1) is described for the test set. The comparison was made directly against the CLSI reference broth microdilution method or expected results for challenge isolates, which serve as the definitive standard.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No, an MRMC comparative effectiveness study was not done. This study evaluates the performance of an automated microbiology system (BD Phoenix™) against a reference standard (CLSI broth microdilution method) for antimicrobial susceptibility testing. It does not involve human readers or assess the improvement of human readers with AI assistance.
6. Standalone (Algorithm Only) Performance Study
- Yes, a standalone performance study was done. The entire study is a standalone evaluation of the BD Phoenix™ Automated Microbiology System (which incorporates an algorithm to interpret results) by comparing its outputs (MIC values and category interpretations) against the CLSI reference method. There is no human-in-the-loop component described in the performance evaluation.
7. Type of Ground Truth Used
The primary ground truth used was the CLSI reference broth microdilution method (AST panels prepared according to NCCLS M7). For challenge isolates, "expected results" were used.
8. Sample Size for the Training Set
The document does not provide information on the sample size used for the training set for the BD Phoenix™ system's underlying algorithms. This is typical for such submissions, as the focus is on the performance of the final, already-developed device.
9. How the Ground Truth for the Training Set Was Established
The document does not provide information on how the ground truth for the training set was established. Similar to the training set sample size, this information is not typically included in the summary for a 510(k) submission for a device like this, which is an automated system rather than a de novo AI model with publicly disclosed training data. It's assumed the system was developed and validated internally using appropriate microbiological standards.
§ 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.”