(77 days)
Antimicrobial Susceptibility Test Discs are used for semi-quantitative in vitro susceptibility testing by standardized agar diffusion test procedures. Grepafloxacin Sensi-Discs® are intended for use in determining the susceptibility to Grepafloxacin of a wide range of bacteria, including Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae, Streptococcus pneumoniae. Streptococcus pyogenes, Citrobacter freundii, Citrobacter (diversus) koseri, Enterobacter aerogenes, Enterobacter cloacae,, Escherichia coli, Haemophilus parainfluenzae, Klebsiella oxytoca, Klebsiella pneumoniae, Morganella morganii, Proteus mirabilis, and Proteus vulgaris. Zone sizes used for interpretation of tests, including control organism limits, were determined by the antimicrobic manufacturer, GlaxoWellcome, Inc., and received FDA approval under NDA No. 50-717.
Use of BBL® Grepafloxacin Sensi-Discs® for in vitro agar diffusion susceptibility testing is indicated when there is a need to determine the susceptibility of bacteria to Grepafloxacin.
Grepafloxacin has been shown to be active against most strains of microorganisms listed below, both in vitro and in clinical infections, as described in the GlaxoWellcome, Inc., package insert for this antimicrobic.
Aerobic Gram-Positive Microorganisms
Streptococcus pneumoniae (penicillin-susceptible strains) Aerobic Gram-Negative Microorganisms
Haemophilus influenzae Moraxella catarrhalis Neisseria gonorrhoeae Other microorganisms Chlamydia trachomatis Mycoplasma pneumoniae
Grepafloxacin exhibits in vitro minimum inhibitory concentrations (MICs) of 1 ug/ml or less against most (≥90%) strains of the microorganisms listed below: however, the safety and effectiveness of Grepafloxacin in treating clinical infections due to these microorganisms have not been established in adequate and well-controlled clinical trials.
Aerobic Gram-Positive Microorganisms (/n Vitro Only)
Staphylococcus aureus (methicillin-susceptible strains) Staphylococcus epidermidis (methicillin-susceptible strains) Streptococcus agalactiae Streptococcus pneumoniae (penicillin-resistant strains) Streptococcus pyogenes
Aerobic Gram-Negative Microorganisms (/n Vitro Only)
Citrobacter freundii Citrobacter (diversus) koseri Enterobacter aerogenes Enterobacter cloacae Escherichia coli Haemophilus parainfluenzae Klebsiella oxytoca Klebsiella pneumoniae Morganella morganii Proteus mirabilis Proteus vulgaris
Antimicrobial Susceptibility Test Discs are used for semi-quantitative in vitro susceptibility testing by standardized agar diffusion test procedures. Grepafloxacin Sensi-Discs® are intended for use in determining the susceptibility to Grepafloxacin of a wide range of bacteria, including Staphylococcus aureus, Staphylococcus epidermidis. Streptococcus agalactiae, Streptococcus pneumoniae, Streptococcus pyogenes, Citrobacter freundii, Citrobacter (diversus) koseri, Enterobacter aerogenes, Enterobacter cloacae,, Escherichia coli, Haemophilus parainfluenzae, Klebsiella oxytoca, Klebsiella pneumoniae, Morganella morganii, Proteus mirabilis, and Proteus vulgaris. Zone sizes used for interpretation of tests, including control organism limits, were determined by the antimicrobic manufacturer, GlaxoWellcome, Inc., and received FDA approval under NDA No. 50-717.
Grepafloxacin Susceptibility Test Discs are prepared by impregnating high quality paper with accurately determined amounts of Grepafloxacin supplied by the manufacturer, GlaxoWellcome, Inc., Research Triangle Park, North Carolina. Each Grepafloxacin disc is clearly marked on both sides with the agent and content. Grepafloxacin discs are furnished in cartridges of 50 discs each. Grepafloxacin cartridges are packed as either a single cartridge in a single box, or in a package containing ten cartridges.
Agar diffusion methods employing dried filter paper discs impregnated with specific concentrations of antimicrobial agents were developed in the 1940's. In order to eliminate or minimize variability in the testing, Bauer et al, developed a standardized procedure in which Mueller Hinton Agar was selected as the test medium.
Various regulatory agencies and standards-writing organizations subsequently published standardized reference procedures based on the Bauer-Kirby method. Among the earliest and most widely accepted of these standardized procedures were those published by the U.S. Food and Drug Administration (FDA) and the World Health Organization (WHO). The procedure was adopted as a consensus standard by the National Committee for Clinical Laboratory Standards (NCCLS) and is periodically updated. The latest NCCLS documents are M2-A6 (1/97) and M100-S7 (1/97).
Discs containing a wide variety of antimicrobial agents are applied to the surface of Mueller Hinton Agar plates for Haemophilus Test Medium Agar for Haemophilus influenzae or Mueller Hinton Agar with 5% Sheep Blood for Streptococcus pneumoniae] inoculated with pure cultures of clinical isolates. Following incubation, the plates are examined and the zones of inhibition surrounding the discs are measured and compared with established zone size ranges for individual antimicrobial agents in order to determine the agent(s) most suitable for use in antimicrobial therapy. The determination as to whether the organism in question is susceptible (S), intermediate (I), or resistant (R) to an antimicrobial agent is made by comparing zone sizes to those found in the respective organism tables of National Committee for Clinical Laboratory Standards (NCCLS) Document M2-A6 ("Performance Standards for Antimicrobial Disk Susceptibility tests - Sixth Edition, Approved Standard", 1/97) and of NCCLS Document M100-S7 ("Performance Standards for Antimicrobial Susceptibility Testing", Seventh Informational Supplement. 1/97).
This document describes the Grepafloxacin, 5 mcg, Sensi-Discs, an antimicrobial susceptibility test device. The information provided heavily references an attached product insert for RAXAR™ Tablets (grepafloxacin hydrochloride tablets) from GlaxoWellcome, Inc. However, this specific submission (K974578) from Becton Dickinson Microbiology Systems does not contain the detailed performance data or acceptance criteria that would typically be found in a study report proving the device meets those criteria.
The submission primarily focuses on the device description, intended use, indications for use, and a declaration of substantial equivalence to a predicate device. It states that "Zone sizes used for interpretation of tests, including control organism limits, were determined by the antimicrobic manufacturer, GlaxoWellcome, Inc., and received FDA approval under NDA No. 50-717." It also references NCCLS documents M2-A6 and M100-S7 for interpretation.
Therefore, many of the requested details about the study are not present in the provided text.
Based on the available information:
1. Table of acceptance criteria and the reported device performance:
The document states that zone sizes and control organism limits "were determined by the antimicrobic manufacturer, GlaxoWellcome, Inc., and received FDA approval under NDA No. 50-717." However, the specific quantitative acceptance criteria (e.g., accuracy percentages, major error rates) and reported device performance against these criteria are not provided in this submission. The submission refers to an attached GlaxoWellcome, Inc., product insert, which is not included in the provided text.
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Not specified in this document; referenced in GlaxoWellcome, Inc. product insert and NCCLS documents M2-A6 and M100-S7. | Not specified in this document; referenced in GlaxoWellcome, Inc. product insert. |
2. Sample size used for the test set and the data provenance:
- Sample size: Not specified in the provided text. The submission mentions "clinical isolates" but gives no specific numbers.
- Data provenance: Not specified in the provided text. The testing procedures mentioned (Bauer-Kirby method, Mueller Hinton Agar) are standard laboratory practices, implying lab-generated data, but details on country of origin or whether it was retrospective/prospective are absent.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
Not specified in the provided text. The ground truth would typically be established by comparing the disc diffusion results to a reference method like broth microdilution Minimum Inhibitory Concentration (MIC) testing. The involvement and qualifications of experts for this comparison are not mentioned.
4. Adjudication method for the test set:
Not specified in the provided text.
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. This is a medical device for in vitro susceptibility testing (disc diffusion), not an AI-powered diagnostic device involving human readers for interpretation. The interpretation is based on measuring zones of inhibition and comparing them to established breakpoints.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
Not applicable. This device is a physical disc impregnated with an antimicrobial agent, used in a traditional laboratory procedure. There is no "algorithm only" performance as it requires human setup, inoculation, incubation, and measurement of inhibition zones.
7. The type of ground truth used:
The ground truth for antimicrobial susceptibility testing is typically established by Minimum Inhibitory Concentration (MIC) values determined by a reference method (e.g., broth microdilution). The document mentions that "Grepafloxacin exhibits in vitro minimum inhibitory concentrations (MICs) of 1 ug/ml or less against most (≥90%) strains of the microorganisms listed below," implying MICs were used as a reference.
8. The sample size for the training set:
Not specified in the provided text. This type of device does not typically involve a "training set" in the context of machine learning. If this refers to the data used to initially establish the zone size breakpoints, those were determined by GlaxoWellcome, Inc., but the sample size is not stated here.
9. How the ground truth for the training set was established:
Not specified in the provided text. The document refers to the antimicrobic manufacturer, GlaxoWellcome, Inc., for the determination of zone sizes and interpretation, which would have been based on correlation with MIC data (the ground truth).
§ 866.1620 Antimicrobial susceptibility test disc.
(a)
Identification. An antimicrobial susceptibility test disc is a device that consists of antimicrobic-impregnated paper discs used to measure by a disc-agar diffusion technique or a disc-broth elution technique the in vitro susceptibility of most clinically important bacterial pathogens to antimicrobial agents. In the disc-agar diffusion technique, bacterial susceptibility is ascertained by directly measuring the magnitude of a zone of bacterial inhibition around the disc on an agar surface. The disc-broth elution technique is associated with an automated rapid susceptibility test system and employs a fluid medium in which susceptibility is ascertained by photometrically measuring changes in bacterial growth resulting when antimicrobial material is eluted from the disc into the fluid medium. Test results are used to determine the antimicrobial agent of choice in the treatment of bacterial diseases.(b)
Classification. Class II (performance standards).