(48 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 ceftriaxone for the removal of the limitation for Proteus vulgaris/penneri from the original premarket notification (K032655, October 6, 2003) and subsequent premarket notification (K060444, April 12, 2006).
Ceftriaxone 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 Clinical Infections Against:
Acinetobacter calcoaceticus
Escherichia coli
Proteus mirabilis
Enterobacter aerogenes
Klebsiella oxytoca
Serratia marcescens
Enterobacter cloacae
Klebsiella pneumoniae
Pseudomonas aeruginosa
Morganella morganii
Proteus vulgaris
Active In Vitro Against:
Citrobacter koseri (formerly C. diversus)
Citrobacter freundii
Providencia species (including Providencia rettgeri)
Salmonella species (including Salmonella typhi)
Shigella species
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 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 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 in the instrument.
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 510(k) summary for the BD Phoenix™ Automated Microbiology System for Ceftriaxone. Here's an analysis of the acceptance criteria and the study that proves the device meets them:
1. A table of acceptance criteria and the reported device performance:
The document compares the BD Phoenix™ Automated Microbiology System's performance to the CLSI reference broth microdilution method. The key metrics reported are Essential Agreement (EA) and Category Agreement (CA).
| Metric | Acceptance Criteria (Implied by FDA Guidance) | Reported Device Performance (Summary) |
|---|---|---|
| Essential Agreement (EA) | Not explicitly stated as a numerical threshold in the provided text, but generally expected to be high for substantial equivalence. Essential Agreement is defined as the BD Phoenix™ Automated Microbiology System agreeing exactly or within ± one two-fold dilution to the reference result. | The study was conducted to demonstrate "substantially equivalent performance" and "accuracy." While specific percentages are not provided in the summary tables, the declaration of "substantially equivalent performance" indicates high agreement. |
| Category Agreement (CA) | Not explicitly stated as a numerical threshold in the provided text, but generally expected to be high for substantial equivalence. Category Agreement is defined as the BD Phoenix™ Automated Microbiology System agreeing with the reference method with respect to the FDA categorical interpretive criteria (susceptible, intermediate, and resistant). | Similar to EA, the study aimed to show "substantially equivalent performance." The statement that "Table 1 summarizes the performance for the isolates tested in this study" followed by the conclusion of substantial equivalence implies acceptable CA values were achieved. |
| Accuracy | Not explicitly detailed as a specific percentage but is the overarching goal of claiming substantial equivalence. | The "Accuracy" section in the table includes "promote problem of Address of Address of Active Station and Concession Collection of Concessfully of Concessfully of Concessfully of Concessfully of Concessfully of Concessfu oncentration" and "Andre ( 8 1 m 3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1" which appear to be corrupted data and do not provide specific numerical accuracy values. However, the subsequent FDA approval indicates the accuracy was found acceptable. |
Note on Acceptance Criteria: The document refers to the FDA guidance document, "Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA", February 5, 2003 as the standard for evaluation. This guidance document would contain the specific numerical acceptance criteria (e.g., minimum percentages for EA and CA) that the study had to meet. These specific numerical thresholds are not explicitly stated within the provided text.
2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective):
- Test Set Sample Size: The exact numerical sample size for the test set is not explicitly stated in the provided text. The document mentions "clinical, stock and challenge isolates were tested." The corrupted "Table 1" shows "No. of Cattle Concession tration oncent." without specific numbers. The "Accuracy" table also does not provide a clear count.
- Data Provenance: The isolates were tested "across multiple geographically diverse sites across the United States." The study included "Clinical, stock and challenge isolates," implying a mix of data sources. It is implicitly prospective or at least a controlled study since it compares the Phoenix System against a CLSI reference method.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g., radiologist with 10 years of experience):
The ground truth was established by the CLSI (Clinical and Laboratory Standards Institute) reference broth microdilution method. This is a standardized laboratory method, not reliant on individual human experts for its "ground truth" establishment in the context of this device. Therefore, there's no mention of a number of experts or their qualifications for establishing the ground truth for the test set.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:
Not applicable. The ground truth for AST performance is determined by a standardized laboratory method (CLSI reference broth microdilution), not through expert adjudication in the typical sense (e.g., for image interpretation).
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:
Not applicable. The BD Phoenix™ Automated Microbiology System is an automated device designed to measure antimicrobial susceptibility. It's not an AI-assisted diagnostic tool that helps human "readers" interpret data. Its performance is compared to a reference lab method, not human interpretation.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
Yes, this was a standalone study. The BD Phoenix™ Automated Microbiology System is an automated device. Its performance (reading and interpreting bacterial growth and susceptibility) is compared directly to the CLSI reference method. The "human-in-the-loop" here is in setting up the test and interpreting the final output, not in the direct measurement or interpretation process itself which is automated by the Phoenix system.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
The ground truth used was the CLSI reference broth microdilution method. This is a recognized and standardized laboratory method for determining antimicrobial susceptibility.
8. The sample size for the training set:
The document does not explicitly mention a "training set" or its size. As a 510(k) submission for an automated laboratory instrument, the validation focuses on the device's accuracy and equivalence to a predicate/reference method. While the Phoenix system's algorithms would have been developed and refined (which could be considered a "training" phase), this specific submission is about its performance validation against established benchmarks, not the iterative development of its internal algorithms.
9. How the ground truth for the training set was established:
Not explicitly detailed for a "training set." The performance of the device (including any underlying algorithms) was validated against the CLSI reference broth microdilution method. The initial development of the Phoenix system's capabilities would have relied on known antimicrobial susceptibility patterns established through years of microbiology research and standardized testing methods.
§ 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.”