(44 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 , Enterococcus, and Streptococcus.
This premarket notification is for the antimicrobial agent erythromycin at concentrations of 0.0156-4 ug/mL to Streptococcus ID/AST or AST only Phoenix panels. Ervthromycin 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:
Streptococcus pneumoniae Streptococcus pyogenes
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. For testing Streptococcus species 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-S Broth used for performing AST tests only. .
- BD Phoenix AST-S 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 isolation 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℃. 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, R or N (susceptible, intermediate, resistant or not susceptible).
Here's a breakdown of the acceptance criteria and study information for the BD Phoenix™ Automated Microbiology System (Erythromycin 0.0156-4 µg/mL):
Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance (Erythromycin) |
|---|---|
| Essential Agreement (EA) with CLSI reference broth microdilution method should meet predefined criteria (presumably a high percentage, common in AST devices is >90%). | Demonstrated substantial equivalence to CLSI reference method. Table for specific performance results is unclear due to text corruption, but the overall conclusion is positive. |
| Category Agreement (CA) with CLSI reference broth microdilution method should meet predefined criteria (presumably a high percentage, common in AST devices is >90%). | Demonstrated substantial equivalence to CLSI reference method. Table for specific performance results is unclear due to text corruption, but the overall conclusion is positive. |
| Intra-site reproducibility | Greater than 90% |
| Inter-site reproducibility | Greater than 95% |
Note on Table 1: The content of Table 1 in the provided text, which should detail the Essential Agreement and Category Agreement, is severely corrupted ("COC
ﻟﻠﺘﻌﻠﻴﻘﺎﺕ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ...") and thus cannot be accurately extracted or presented. However, the accompanying text states that the performance was "assessed by calculating Essential Agreement (EA) and Category Agreement (CA)" and that the study "demonstrates that testing on the BD Phoenix™ Automated Microbiology System with this antimicrobial agent is substantially equivalent." This implies that the acceptance criteria for EA and CA were met.
Study Information
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Sample size used for the test set and the data provenance:
- Test Set Sample Size: Not explicitly stated as a number, but isolates included "Clinical, stock and challenge isolates."
- Data Provenance: Multiple geographically diverse sites across the United States. The text implicitly indicates prospective data for clinical isolates as they were "tested across multiple geographically diverse sites."
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not explicitly stated. The ground truth method, CLSI reference broth microdilution method, is a standardized laboratory procedure and does not typically involve interpretation by a panel of human experts in the same way an imaging study would.
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Adjudication method for the test set: Not applicable in the traditional sense of human adjudication. The reference method (CLSI broth microdilution) provides a direct, quantitative MIC result, which is then categorized and compared to the device's output.
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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: Not applicable. This is an automated antimicrobial susceptibility test system, not an imaging or diagnostic device that relies on human readers' interpretation.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Yes, the study evaluated the "BD Phoenix™ Automated Microbiology System" which is an automated system providing results without explicit human intervention in the interpretation of the raw signals from the panels. The system generates MIC values and categorical interpretations (S, I, R, N).
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The type of ground truth used:
- For clinical isolates: CLSI reference broth microdilution method.
- For challenge isolates: Expected results.
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The sample size for the training set: Not applicable/not discussed. This device is based on a fixed principle of detecting bacterial growth and changes in a redox indicator in the presence of antimicrobial agents, rather than being a machine learning algorithm that requires a "training set" in the conventional AI sense. The system's "training" would be its initial calibration and validation procedures during development.
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How the ground truth for the training set was established: Not applicable, as there's no explicitly defined "training set" in the context of this device's validation. The system's underlying principles and calibration would be based on established microbiology standards and empirical data.
§ 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.”