(77 days)
VITEK® 2 Streptococcus Tetracycline is designed for antimicrobial susceptibility testing of Streptococcus species and is intended for use with the VITEK® 2 and VITEK® 2 COMPACT Systems as a laboratory aid in the determination of in vitro susceptibility to antimicrobial agents. VITEK®2 Streptococcus Tetracycline is a quantitative test. Tetracycline has been shown to be active against the microorganisms listed below, according to the FDA label for this antimicrobial.
Active in vitro and in clinical infections: Streptococcus pneumoniae Streptococcus pyogenes*
*The VITEK® 2 Streptococcus Susceptibility Card also reports the susceptibility of the following additional organisms as listed on the FDA Susceptibility Test Interpretative Criteria website (STIC): Streptococcus spp. B-Hemolytic Group (other than S. pyogenes).
The VITEK® 2 Streptococcus Susceptibility Card is intended for use with the VITEK® 2 Systems in clinical laboratories as an in vitro test to determine the susceptibility of Streptococcus pneumoniae, beta-hemolytic Streptococcus, and Viridans Streptococcus to antimicrobial agents when used as instructed.
The principle of the VITEK® 2 AST cards is based on the microdilution minimum inhibitory concentration (MIC) technique reported by MacLowry and Marsh(1) and Gerlach(2). The VITEK® 2 AST card is essentially a miniaturized, abbreviated and automated version of the doubling dilution technique(3).
Each VITEK® 2 AST card contains 64 wells. A control well which only contains microbiological culture media is resident on all cards. The remaining wells contain premeasured portions of a specific antibiotic combined with culture media. The bacterial or yeast isolate to be tested is diluted to a standardized concentration with 0.45 -0.5% saline before being used to rehydrate the antimicrobial medium within the card. The VITEK® 2 System automatically fills, seals and places the card into the incubator/reader. The VITEK® 2 Compact has a manual filling, sealing and loading operation. The VITEK® 2 Systems monitor the growth of each well in the card over a defined period of time. At the completion of the incubation cycle, a report is generated that contains the MIC value along with the interpretive category result for each antibiotic contained on the card.
VITEK® 2 Streptococcus Tetracycline has the following concentrations in the card: 0.125, 0.5, 1, and 4 ug/mL (equivalent standard method concentration by efficacy in ug/mL).
Here's an analysis of the acceptance criteria and study proving the device meets those criteria, based on the provided text:
Device: VITEK® 2 Streptococcus Tetracycline (≤0.25 - ≥16 µg/mL)
Intended Use: Antimicrobial susceptibility testing of Streptococcus species, as a laboratory aid in determining in vitro susceptibility to antimicrobial agents. Specifically for Streptococcus pneumoniae and Streptococcus pyogenes, with additional reporting for Beta-hemolytic Streptococcus (other than S. pyogenes).
Acceptance Criteria and Reported Device Performance
The study compared the VITEK® 2 Streptococcus Tetracycline performance against the CLSI broth microdilution reference method. The acceptance criteria are implicitly defined by the guidance document cited: "FDA Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA (Issued August 28, 2009)."
| Acceptance Metric | Requirement (Implied by FDA Guidance and Overall Performance) | Reported Device Performance |
|---|---|---|
| Overall Essential Agreement (EA) | Generally, >90% (industry standard for AST systems) | 98.3% |
| Overall Category Agreement (CA) | Generally, >90% (industry standard for AST systems) | 97.9% |
| Very Major Errors (VME) for S. pneumoniae | N/A (Not Applicable - typically assessed for Resistant to Susceptible mismatches, but the table shows N/A) | 0.0% |
| Major Errors (ME) for S. pneumoniae | N/A (Not Applicable - typically assessed for Susceptible to Resistant mismatches) | 0.0% |
| Minor Errors (mE) for S. pneumoniae | Low (e.g., |
§ 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.”