(97 days)
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 ceftaroline at concentrations of 0.0625-4 ug/ml. to Gram-positive ID/AST or AST only Phoenix panels. Ceftaroline has been shown to be active in vitro against most strains of microorganisms listed below, as described in the FDA-approved package inserts for this antimicrobial agent.
Active In Vitro and in Clinical Infections Against:
Staphylococcus aureus (including methicillin-susceptible and -resistant isolates)
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 instrument houses the panels where they are continuously incubated at a nominal temperature of 35° ± 1°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, R or N (susceptible, intermediate, resistant or not susceptible).
Here's an analysis of the acceptance criteria and study as described in the provided 510(k) summary (K140468):
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are not explicitly stated as numerical targets in a table format within the provided document. However, the study aims to demonstrate "substantial equivalence" based on Essential Agreement (EA) and Category Agreement (CA) values derived from comparisons to a reference method. The implicit acceptance criteria are high percentages for these agreement metrics. The document states that overall reproducibility was "greater than 95% (+/- 1 dilution) agreement."
| Metric / Agreement Type | Acceptance Criteria (Implicit) | Reported Device Performance (Ceftaroline, Gram-Positive Organisms) |
|---|---|---|
| Essential Agreement (EA) | High percentage (e.g., >90-95%) | 94.7% (n=866) |
| Category Agreement (CA) | High percentage (e.g., >95-98%) | 98.2% (n=866) |
| Intra- and Inter-site Reproducibility | >95% (+/- 1 dilution) | >95% (+/- 1 dilution) |
2. Sample Size Used for the Test Set and the Data Provenance
- Sample Size for Test Set:
- Clinical and Challenge Isolates (Combined): 866 (This is the 'n' value for both EA and CA in the provided table). The document refers to "all isolates tested" when summarizing this performance.
- Reproducibility Study: A "panel of Gram-positive isolates" was tested at three sites. The specific number of isolates is not explicitly stated, but each was tested in triplicate on three different days.
- Data Provenance: The isolates were tested "across multiple geographically diverse sites across the United States." This indicates a prospective collection of data from clinical, stock, and challenge isolates.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts
The ground truth was established by the CLSI (Clinical and Laboratory Standards Institute) reference broth microdilution method. This is a standardized laboratory method, not dependent on individual expert interpretation. Therefore, there were no individual human experts establishing the ground truth in the traditional sense for the MIC values.
4. Adjudication Method for the Test Set
Not applicable. The ground truth was established by a standardized laboratory method (CLSI reference broth microdilution method), which does not involve human adjudication for reconciling differing interpretations among experts.
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
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not conducted. This device is an automated system for determining antimicrobial susceptibility, not an imaging or diagnostic device that assists human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, a standalone performance study was done. The BD Phoenix™ Automated Microbiology System is an automated system that performs identification and susceptibility testing. The study directly compares the Phoenix System's results (algorithm's output) to the CLSI reference method, which is a standalone performance assessment of the device.
7. The Type of Ground Truth Used
The type of ground truth used was a standardized laboratory reference method: the CLSI reference broth microdilution method (specifically CLSI M7). For challenge isolates, "expected results" were used, which would typically come from well-characterized strains with known susceptibility profiles as determined by the reference method.
8. The Sample Size for the Training Set
The document does not provide information regarding the sample size used for the training set. The focus of this 510(k) summary is on the validation or performance testing of the device rather than its development or training phase.
9. How the Ground Truth for the Training Set Was Established
The document does not provide information on how the ground truth for any training set might have been established. Given that this is a 510(k) submission for a specific antimicrobial agent (Ceftaroline) on an existing platform (BD Phoenix), the "training" (if applicable) likely occurred during the earlier development and validation of the core Phoenix system and methodologies, for which details are not included in this document. Any ground truth for training would also typically rely on the CLSI reference broth microdilution 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.”