(133 days)
The illumigene Group B Streptococcus (GBS) assay, performed on the illumipro-10™, is a qualitative in vitro diagnostic for the detection of Streptococcus agalactiae in enriched cultures obtained from vaginal/rectal swab specimens from antepartum women. Enriched cultures are obtained by 18 - 24 hour incubation of vaginal/rectal swab specimens in selective broth medium, either Lim Broth [Todd Hewitt Broth supplemented with colistin (10 µg/mL) and nalidixic acid (15 µg/mL )] or TransVag Broth (Todd-Hewitt broth supplemented with gentamycin (8 µg/ml.) and nalidixic acid (15 ug/mL)].
The illumigene GBS assay utilizes loop-mediated isothermal DNA amplification (LAMP) technology to detect Streptococcus agoloctioe by targeting a segment of the Streptococcus ogolactiae genome. Results from the illumigene GBS assay can be used as an aid in establishing the GBS colonization status of antepartum women. This assay is not intended to diagnose or monitor treatment for GBS infections.
The illumigene GBS assay does not provide susceptibility results. Culture isolates are needed for performing susceptibility testing as recommended for penicillin-allergic women.
illumigene Group B Streptococus is intended for use in hospital, reference or state laboratory settings. The device is not intended for point-of-care use.
The illumicene Molecular Diagnostic Test System is comprised of the illumigene® Group B Streptococcus (GBS) DNA Amplification Test Kit, the illumiqene Group B Streptococcus (GBS) External Control Kit and the illumipro-10 Automated Isothernal Amplification and Detection System.
The illumicene Group B Streptococus (GBS) DNA amplification assay utilizes loog-mediated isothermal amplification (LAMP) technology to detect the presence of Streptococus agatatiae in enriched from vaginal/rectal swab specimens taken from antepartum women. Each illumigene GBS assay is completed using illumigene Reaction Buffer, an illumigene GBS Test Device, and an illumigene Heat Treatment Tube. Samples are diluted with the illumigene Control Reagent, target DNA is made available for isothermal amplification via heat-treatment in the illumigene Heat Treatment Tube and DNA amplification occurs in the illumigene GBS Test Device.
The illumipro-10 heats each illumigene GBS Test Device containing prepared samples and Control Reagent, facilitating amplification of target DNA. When S. agalaction is present in the enriched culture sample, a conserved sequence of the S. agalified and magnesium pyrophosphate is formed. Magnesium pyrophosphate in the reaction mixture. The illumipro-10 detects the change in light transmission mixture created by the precipitating magnesium pyrophosphate. Sample results are reported as Positive or Negative based on the detected change in light transmission.
The illumigene Group B Streptococus (GBS) External Control Kit consists of a Positive Control Reagent and a Negative Control Reagent. External Control reagents are provided to aid the user in detection of reagent deterioration, adverse environmental or test conditions, or variance in operator performance that may lead to test errors. The illumigene Group B Streptococus External Control Kit is required for routine Quality Control.
Here's an analysis of the illumigene® GBS DNA Amplification Assay's acceptance criteria and the study proving it, based on the provided 510(k) Summary Statement:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are not explicitly stated as distinct numerical targets in the provided document. Instead, the "Performance Comparison, Clinical Tests" section implicitly sets the acceptance criteria through the reported sensitivity and specificity values. The device presumably met the internal criteria by demonstrating these performance characteristics.
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance (Overall) | 95% Confidence Interval |
|---|---|---|---|
| Sensitivity | High (e.g., >95%) | 97.4% | 91.9% - 99.0% |
| Specificity | High (e.g., >90%) | 92.3% | 90.0% - 94.1% |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: 826 qualified patient samples.
- Data Provenance: Retrospective and prospective (implied by "clinical trials... were conducted in 2011" and samples were "obtained according to the collection of clinical specimens"). The samples originated from the Midwestern and Southern regions of the United States.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not specify the number of experts or their qualifications for establishing the ground truth.
4. Adjudication Method for the Test Set
The document does not explicitly state an adjudication method. It mentions that "Specimens that generated discrepant results were further evaluated by independent testing laboratories using FDA cleared or laboratory validated molecular assays." This suggests an ad-hoc adjudication process for discrepant cases rather than a predetermined expert consensus method.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, an MRMC comparative effectiveness study involving human readers with/without AI assistance was not mentioned. The device is a diagnostic assay, and its performance was compared to bacterial culture, not human expert interpretation.
6. Standalone (Algorithm Only) Performance
Yes, a standalone performance study was conducted. The "Performance Comparison, Clinical Tests" section directly reports the sensitivity and specificity of the illumigene® GBS assay based on its direct application to enriched patient samples, without human interpretation of the assay's output (Positive/Negative).
7. Type of Ground Truth Used
The ground truth used was bacterial culture enrichment followed by bacterial culture with Group B Streptococcus identification. This is explicitly stated as the "Reference comparator."
8. Sample Size for the Training Set
The document does not explicitly state the sample size for the training set. It describes assay development and analytical sensitivity testing, but not a distinct training set in the context of machine learning. The "Clinical trials" section refers to clinical validation, not training.
9. How the Ground Truth for the Training Set Was Established
As no specific "training set" with established ground truth is detailed in the document, this question cannot be fully answered. However, the overall ground truth method for the clinical validation was bacterial culture enrichment and identification (as noted in point 7). It is reasonable to assume similar methods were used for any internal development or calibration datasets.
§ 866.3740
Streptococcus spp. serological reagents.(a)
Identification. Streptococcus spp. serological reagents are devices that consist of antigens and antisera (excluding streptococcal exoenzyme reagents made from enzymes secreted by streptococci) used in serological tests to identifyStreptococcus spp. from cultured isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by bacteria belonging to the genusStreptococcus and provides epidemiological information on these diseases. Pathogenic streptococci are associated with infections, such as sore throat, impetigo (an infection characterized by small pustules on the skin), urinary tract infections, rheumatic fever, and kidney disease.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 866.9.