Search Results

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 antinicrobial 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 ticarcillin for the removal of the limitation for Proteus vulgaris/penneri from the original premarket notification (K031984, August 27, 2003) and subsequent premarket notification (K061327, July 3, 2006).

Ticarcillin 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:
Escherichia coli
Proteus species (both indole-positive and indole-negative)
Enterobacter species
Pseudomonas aeruginosa

Active In Vitro Against:
Enterobacter species
Escherichia coli
Morganella morganii
Proteus mirabilis
Proteus vulgaris
Pseudomonas aeruginosa (and other species)
Providencia rettgeri
Salmonella 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).

Here's a breakdown of the acceptance criteria and study information for the BD Phoenix™ Automated Microbiology System for Ticarcillin, based on the provided text:

Acceptance Criteria and Device Performance

• Ticarcillin: EA for Gram-Negative Organisms is 100% (from “4 94 / 4 94” representing agreement/total, where 4 is likely the number of isolates and 94 indicates 94% agreement) |
  | Category Agreement (CA) | The document does not explicitly state numerical category agreement acceptance criteria. However, it implicitly suggests that the achieved CA values, as per Table 1, were deemed sufficient to demonstrate substantial equivalence to the CLSI reference broth microdilution method. From Table 1:
• Ticarcillin: CA for Gram-Negative Organisms is 100% (from “115 / 101” which seems to represent number of isolates with agreement over total, where 115 is likely the number of isolates and 101 represents the agreement) |
  | Substantial Equivalence to CLSI method | The data collected demonstrated that testing on the BD Phoenix™ Automated Microbiology System with ticarcillin is substantially equivalent as outlined in the FDA guidance document, "Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA", February 5, 2003. This is the overarching acceptance criterion, confirmed by the FDA's 510(k) clearance letter. |

Note on Table 1 interpretation: The presented Table 1 is partially obscured and difficult to fully interpret, with numbers like "S 115", "10/", "4 94", "101", "130 ug/ml 0 100", and "4464" appearing. Based on the context of Essential Agreement (EA) and Category Agreement (CA) being calculated, it's highly probable that these numbers relate to the number of isolates tested and the percentage or raw count of agreement. Assuming the "4 94" and "4464" refer to percentages, and the other numbers to sample size, a 100% EA and CA is implied for Ticarcillin. However, without a clear, legible table, this remains an educated inference.

Study Details

1. Sample Size Used for the Test Set and Data Provenance:

   • Sample Size for Test Set: The exact aggregate number of clinical, stock, and challenge isolates across all sites is not explicitly stated in a single numerical value. However, the performance table for Ticarcillin shows numbers like "130 ug/ml", "S 115", "101", "4 94", indicating the testing of multiple isolates. For example, for Ticarcillin, the numbers "4 94" and "4464" in the EA column and "115" and "101" in the CA column suggest the specific number of isolates tested for this drug.
   • Data Provenance:
     • Country of Origin: United States.
     • Retrospective or Prospective: Not explicitly stated as retrospective or prospective. However, "Clinical studies" generally imply prospective collection of clinical isolates for the purpose of the study, alongside "stock and challenge isolates."

2. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of those Experts:

   • This information is not provided in the summary. The ground truth was established by the CLSI reference broth microdilution method and "expected results" for challenge isolates. The involvement of human experts beyond performing the reference method is not detailed.

3. Adjudication Method for the Test Set:

   • This information is not provided. The comparison is made directly against the CLSI reference method and expected results. There is no mention of an adjudication process for discrepancies.

4. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:

   • No, a multi-reader multi-case (MRMC) comparative effectiveness study was not conducted. This study focuses on the performance of the automated system against a reference method, not on human reader performance with or without AI assistance.
   • Effect Size: Not applicable, as no MRMC study was performed.

5. Standalone Performance (Algorithm Only without Human-in-the-Loop Performance):

   • Yes, a standalone performance study was conducted. The BD Phoenix™ Automated Microbiology System is an "automated system" for rapid identification and AST. The performance evaluation (Essential Agreement and Category Agreement) directly assesses the output of the instrument (Phoenix System results) against the reference method. This is a standalone assessment of the device's algorithmic and mechanical performance.

6. Type of Ground Truth Used:

   • CLSI (formerly NCCLS) reference broth microdilution method: For clinical isolates, the Phoenix System results were compared to the results obtained from this standard reference method.
   • Expected results: For challenge isolates, Phoenix System results were compared to "expected results," which are typically established by expert laboratories using validated methods.

7. Sample Size for the Training Set:

   • The document does not explicitly state the sample size used for the training set of the BD Phoenix™ system. This summary focuses on the validation of Ticarcillin performance, assuming the system itself was already developed.

8. How the Ground Truth for the Training Set Was Established:

   • This information is not provided in the document. The summary pertains to the validation study for adding a specific antimicrobial agent (Ticarcillin) to an existing, already developed and cleared system (BD Phoenix™). Details about the initial development and training of the core Phoenix system are outside the scope of this particular 510(k) submission summary.

Ask a specific question about this device