K Number
K121364
Date Cleared
2012-10-02

(148 days)

Product Code
Regulation Number
866.3255
Reference & Predicate Devices
Predicate For
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP AuthorizedThirdpartyExpeditedreview
Intended Use

The SHIGA TOXIN QUIK CHEK test is a rapid membrane enzyme immunoassay for the simultaneous qualitative detection and differentiation of Shiga toxin 1 (Stx1) and Shiga toxin 2 (Stx2) in a single test device. It is intended for use with human fecal samples from patients with gastrointestinal symptoms to aid in the diagnosis of disease caused by Shiga toxin producing Escherichia coli (STEC). It may be used with fecal specimens, or broth or plate cultures derived from fecal specimens. The test results should be considered in conjunction with the patient history.

FOR IN VITRO DIAGNOSTIC USE.

Device Description

The SHIGA TOXIN QUIK CHEK test utilizes specific antibodies against Stx1 and Stx2. The Membrane Device contains a Reaction Window with three vertical lines of immobilized antibodies. The "1" test line contains monoclonal antibodies against Stx1. The control line ("C") is a dotted line that contains anti-horseradish peroxidase (HRP) antibodies. The "2" test line contains monoclonal antibodies against Stx2. The Conjugate consists of antibodies to Stx1 and Stx2 coupled to horseradish peroxidase. To perform the test, the sample is added to a tube containing a mixture of Diluent and Conjugate. The diluted sample-coniugate mixture is added to the Sample Well and the device is allowed to incubate at room temperature for 15 minutes. During the incubation, any Stx1 and/or Stx2 present in the sample binds to the antibodyperoxidase conjugates. The toxin-antibody-peroxidase complexes migrate through a filter pad to a membrane where they are captured by the immobilized Stx1 and Stx2 specific monoclonal antibodies in the test lines. The Reaction Window is subsequently washed with Wash Buffer, followed by the addition of Substrate. After a 10 minute incubation period, the Reaction Window is examined visually for the appearance of vertical blue lines on the "1" and "2" sides of the Reaction Window. A blue line on the "1" side of the Reaction Window is a positive result indicating the presence of Stx1. A blue line on the "2" side of the Reaction Window is a positive result indicating the presence of Stx2. A positive "C" reaction, indicated by a vertical dotted blue line under the "C" portion of the Reaction Window, confirms that the test is working properly, the procedure was followed, and the results are valid.

AI/ML Overview

Here's a summary of the acceptance criteria and study details for the SHIGA TOXIN QUIK CHEK device, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state pre-defined acceptance criteria in terms of specific percentages for sensitivity, specificity, and correlation for the clinical performance. Instead, it presents the achieved performance metrics as the outcome of the clinical study. However, the study's findings indicate the device's acceptable performance for its intended use. For the analytical sensitivity, the cutoff points are explicitly defined as the acceptance criteria.

Metric (Stx1 - Direct Fecal)Acceptance Criteria (Implicit from Results)Reported Device Performance
SensitivityHigh sensitivity to detect Stx198.0% (87.8 - 99.9% CI)
SpecificityHigh specificity to rule out Stx199.8% (99.0 - 99.9% CI)
CorrelationHigh overall agreement with Gold Standard99.7% (99.7 - 99.7% CI)
Metric (Stx2 - Direct Fecal)Acceptance Criteria (Implicit from Results)Reported Device Performance
SensitivityHigh sensitivity to detect Stx298.0% (87.8 - 99.9% CI)
SpecificityHigh specificity to rule out Stx2100% (99.4 - 99.9% CI)
CorrelationHigh overall agreement with Gold Standard99.9% (100 - 100% CI)
Metric (Stx1 - Broth Cultures)Acceptance Criteria (Implicit from Results)Reported Device Performance
SensitivityHigh sensitivity to detect Stx1100% (89.6 - 100% CI)
SpecificityHigh specificity to rule out Stx199.5% (98.5 - 99.8% CI)
CorrelationHigh overall agreement with Gold Standard99.5% (99.5 - 99.5% CI)
Metric (Stx2 - Broth Cultures)Acceptance Criteria (Implicit from Results)Reported Device Performance
SensitivityHigh sensitivity to detect Stx295.7% (84.3-99.3% CI)
SpecificityHigh specificity to rule out Stx299.9% (99.1 - 100% CI)
CorrelationHigh overall agreement with Gold Standard99.6% (99.6 - 99.6% CI)
Metric (Analytical Sensitivity)Acceptance CriteriaReported Device Performance
Stx1 Cutoff (Direct Fecal)Concentration yielding positive results 95% of the time, negative 5% of time0.04 ng/mL (found empirically at 0.042 ng/mL)
Stx2 Cutoff (Direct Fecal)Concentration yielding positive results 95% of the time, negative 5% of time0.04 ng/mL (found empirically at 0.039 ng/mL)
Stx1 Cutoff (Broth Cultures)Concentration yielding positive results 95% of the time, negative 5% of time0.04 ng/mL (found empirically at 0.042 ng/mL)
Stx2 Cutoff (Broth Cultures)Concentration yielding positive results 95% of the time, negative 5% of time0.04 ng/mL (found empirically at 0.039 ng/mL)

2. Sample Size Used for the Test Set and Data Provenance

  • Direct Fecal Testing:
    • Sample Size: 887 specimens (873 fresh, 14 frozen).
    • Data Provenance: Not explicitly stated, but the study was conducted at 3 independent sites, implying clinical samples collected from patients. It does not specify country of origin or whether samples were prospective or retrospective, only that age and sex information was available for 878 patients.
  • Broth Cultures Testing:
    • Sample Size: 770 specimens (overnight broth cultures from fecal specimens).
    • Data Provenance: Not explicitly stated, but derived from fecal specimens.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications

The document does not explicitly state the number of experts or their specific qualifications (e.g., number of years of experience).

4. Adjudication Method for the Test Set

The document does not describe an adjudication method for disagreements. The comparison was made against a single "gold standard" reference method.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done

No, an MRMC comparative effectiveness study involving human readers with and without AI assistance was not mentioned. This device is an in vitro diagnostic device for lab use, not an AI-assisted diagnostic tool for human readers.

6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done

Yes, the clinical performance study compares the SHIGA TOXIN QUIK CHEK device directly against the gold standard (Vero Cell Cytotoxin Assay), indicating a standalone assessment of the device's performance. The results are based solely on the device's output.

7. The Type of Ground Truth Used

The ground truth used for establishing clinical performance was the Vero Cell Cytotoxin Assay (with neutralization), which is referred to as the "clinical reference standard (gold standard)".

8. The Sample Size for the Training Set

The document describes the device's validation but does not mention a separate "training set" in the context of machine learning or AI models. This is an in vitro diagnostic test, and its development typically involves internal analytical studies rather than a distinct training/test set split as seen in AI algorithms.

9. How the Ground Truth for the Training Set Was Established

As there's no mention of a "training set" for an AI model, this question is not applicable in the context of this traditional in vitro diagnostic device. The device's analytical setup (e.g., cutoff points for LOD) was established empirically using purified toxins and negative fecal/broth pools, following established protocols (EP17A).

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Image /page/0/Picture/0 description: The image shows the word "TECHLAB" in a bold, sans-serif font. The word is enclosed in an oval shape. The letter "B" has a small circle next to it, which is likely a registered trademark symbol.

5121364

ОСТ

2 2012

SHIGA TOXIN QUIK CHEK 510(k) SUMMARY

This summary of 510(k) safety and effectiveness is being submitted in accordance with the requirements of 21 CFR 807.92.

Applicant/Contact Information:

Date Prepared:
Name:
Address:

October 02, 2012
TECHLAB®, Inc. 2001 Kraft Drive Corporate Research Center Blacksburg, VA 24060

Contact Person:
Phone Number:
Email:

Donna T. Link 540-953-1664 dlink@techlab.com

MAT

Signature:

1.1 Manufacturing Facility Address

TECHLAB®, Inc. 2001 Kraft Drive Blacksburg, VA 24060-6358

1.2 Product and Trade Name of the Device

SHIGA TOXIN QUIK CHEK

1.3 Common Name or Classification Name

E. coli toxins detection test

1.4 Classification and Regulation

Class I 21 CFR 866.3255; Escherichia coli serological reagents

1.5 Product Code(s)

GMZ - Antigens, all types, Escherichia coli

.

1.6 Panel 83 Microbiology

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Intended Use

The SHIGA TOXIN QUIK CHEK test is a rapid membrane enzyme immunoassay for the simultaneous qualitative detection and differentiation of Shiga toxin 1 (Stx1) and Shiga toxin 2 (Stx2) in a single test device. It is intended for use with human fecal samples from patients with gastrointestinal symptoms to aid in the diagnosis of disease caused by Shiga toxin producing Escherichia coli (STEC). It may be used with fecal specimens, or broth or plate cultures derived from fecal specimens. The test results should be considered in conjunction with the patient history.

Explanation

Shiga toxin producing Escherichia coli (STEC) were first described by O' Brien, et al, after discovering that E. coli culture supernatant, which was cytotoxic to HeLa and Vero cells, could be neutralized by rabbit antibodies. STEC cause foodborne and waterborne diarrheal disease worldwide which, if left undiagnosed, can progress to hemorrhagic colitis and/or hemolytic uremic syndrome (HUS). Since certain treatments and medications can increase the risk of HUS, prompt detection is necessary to prevent outbreaks and secondary transmission. STEC strain 0157:H7 has historically been the focus of attention in the United States since first isolated from undercooked hamburgers, causing an estimated 73,000 illnesses annually. However, STEC infections caused by non-O157 strains have become more prevalent in recent years, both in the United States as well as abroad. 0157:H7 infections are routinely diagnosed by culture of fecal samples on selective media, but this methodology allows non-0157 STEC strains to go undetected. STEC produce either one or both Shiga toxins (Stx1 and/or Stx2), both potent cytotoxins. Isolates producing only Stx2 have been attributed to higher incidence rates of HUS. Shiga toxins can be detected by tissue culture assay, but this method is both time consuming and labor intensive. By detecting the SHIGA TOXIN QUIK CHEK test can detect STEC present in fecal samples or culture, regardless of the serotype or other virulence factors.

Device Description

The SHIGA TOXIN QUIK CHEK test utilizes specific antibodies against Stx1 and Stx2. The Membrane Device contains a Reaction Window with three vertical lines of immobilized antibodies. The "1" test line contains monoclonal antibodies against Stx1. The control line ("C") is a dotted line that contains anti-horseradish peroxidase (HRP) antibodies. The "2" test line contains monoclonal antibodies against Stx2. The Conjugate consists of antibodies to Stx1 and Stx2 coupled to horseradish peroxidase. To perform the test, the sample is added to a tube containing a mixture of Diluent and Conjugate. The diluted sample-coniugate mixture is added to the Sample Well and the device is allowed to incubate at room temperature for 15 minutes. During the incubation, any Stx1 and/or Stx2 present in the sample binds to the antibodyperoxidase conjugates. The toxin-antibody-peroxidase complexes migrate through a filter pad to a membrane where they are captured by the immobilized Stx1 and Stx2 specific monoclonal antibodies in the test lines. The Reaction Window is subsequently washed with Wash Buffer, followed by the addition of Substrate. After a 10 minute incubation period, the Reaction Window is examined visually for the appearance of vertical blue lines on the "1" and "2" sides of the Reaction Window. A blue line on the "1" side of the Reaction Window is a positive result indicating the presence of Stx1. A blue line on the "2" side of the Reaction Window is a positive result indicating the presence of Stx2. A positive "C" reaction, indicated by a vertical dotted blue line under the "C" portion of the Reaction Window, confirms that the test is working properly, the procedure was followed, and the results are valid.

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Materials Provided

Membrane Devices - each pouch contains 1 device

Diluent (22 mL per bottle) - Buffered protein solution with graduated dropper assembly Wash Buffer (12 mL per bottle) – Buffered solution with graduated dropper assembly Substrate (3.5 mL per bottle) - Solution containing tetramethylbenzidine

Conjugate (2.5 mL per bottle) - Antibodies specific for Stx1 and Stx2 coupled to horseradish peroxidase in a buffered protein solution

Positive Control (1 mL per bottle) – Antigen in a buffered protein solution

Disposable plastic transfer pipettes – graduated at 25 μL, 100 μL, 200 μL, 300 μL, 400 μL and 500 µL

WD In Vitro Diagnostic Medical Device

Comparative Information of Predicate Devices

Kit Name510(k)NumbersIntended UseFormatTarget Population
Vero Cell CytotoxinAssay (withneutralization)*ClinicalReferenceStandard(goldstandard)Detection of Shigatoxins 1 and 2 fromfecal specimens, brothcultures, individualcolonies or colonysweeps of agar platesCell culturecytotoxicity andneutralizationPersons suspected ofhaving STEC infection
Premier™ EHECK953362Detection of Shigatoxins 1 and 2 fromdirect fecal samples,broth cultures of fecalspecimens, individualcolonies or colonysweeps of agar platesMicrowell ELISAPersons suspected ofhaving STEC infection
ImmunoCard Stat!EHECK062546Detection of Shigatoxins 1 and 2 incultures derived fromclinical stool specimensImmuno-chromatographicrapid testPersons suspected ofhaving STEC infection
ProSpecT ShigaToxin E. coli (EHEC)Microplate ELISAK980507Detection of Shigatoxins (Stx1 and Stx2)in aqueous extracts offecal specimens andbroth enriched fecalculturesMicroplate ELISAPersons suspected ofhaving STEC infection

*Comparative device used to establish equivalency.

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Similarities
ItemSHIGA TOXIN QUIKCHEKImmunoCard STAT!EHECK062546PREMIER EHECK953362ProSpecT ShigaToxin E. coli (STEC)K980507
IntendedUseQualitative Detection ofShiga toxins 1 and 2Qualitative Detection ofShiga toxins 1 and 2Qualitative Detection ofShiga toxins 1 and 2Qualitative Detectionof Shiga toxins 1 and2
TechnologyEnzyme ImmunoassayImmunochromatographic(lateral flow)Enzyme ImmunoassayEnzyme Immunoassay
AntibodyFormatMonoclonal/PolyclonalMonoclonal/PolyclonalMonoclonal/PolyclonalMonoclonal/Polyclonal
Differences
ItemSHIGA TOXINQUIK CHEKImmunoCard STAT!EHECPREMIER EHECProSpecT Shiga ToxinE. coli (STEC)
Intended UseDifferentiation ofShiga toxins 1 and 2Non-differentiationNon-differentiationNon-differentiation
TechnologyRapid MembraneEnzymeImmunoassayImmunochromatographic(lateral flow)Enzyme Immunoassay- Microwell PlateELISAEnzyme Immunoassay -Microwell Plate ELISA
SpecimenTypesDirect Human FecalSpecimensBroth CulturesPlate culturesBroth and Plate CulturesonlyDirect Human FecalSpecimensBroth culturesPlate culturesDirect Human FecalSpecimensBroth cultures
Amount ofSpecimenrequired25 µL - fecal100 µL - transportmedia or brothculture50 µL - fecal50 µL - fecal300 µL - fecal
Time to Result30 minutes25 minutesafter the 16-24 hr.enrichment procedure2 hour 15 minutes1 hour 50 minutes

· . .

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Summary of Performance Data

Predicate Device Method Comparison N/A

Other Method Comparison - Clinical Reference Standard (Gold Standard)

Vero Cell Cytotoxin Assay with neutralization

Clinical Performance

The performance of the SHIGA TOXIN QUIK CHEK test was evaluated at 3 independent sites. A summary of overall performance at the 3 sites follows.

Direct Fecal Testing

The performance of the SHIGA TOXIN QUIK CHEK (STQC) test was compared to the Vero Cell Cytotoxin Assay (with neutralization), considered the clinical reference standard (gold standard) and included 873 fresh and 14 frozen samples. Age and sex information was available for 878 patients. Of the 878 patients, 8% were ≤ 18 years and 59.8% were females and 40.2% were males. The following tables show a summary of the clinical performance of the Stx1 portion and the Stx2 portion of the SHIGA TOXIN QUIK CHEK test at all 3 sites. The results show that the Stx1 portion exhibited a sensitivity of 98.0%, a specificity of 99.8%, and an overall correlation of 99.7% with cytotoxin assay. The Stx2 portion exhibited a sensitivity of 98.0%, a specificity of 100%, and an overall correlation of 99.9% with cytotoxin assay.

Direct Fecal Testing Results

Vero Cell Cytotoxin AssayVero Cell Cytotoxin Assay
n = 887Stx 1 +Stx 1 -n = 887Stx 2 +Stx 2 -
STQCStx1 +482STQCStx2 +480
STQCStx1 -1836STQCStx2 -1838
95% ConfidenceInterval
Sensitivity98.0%87.8 - 99.9%
Specificity99.8%99.0 - 99.9%
Correlation99.7%99.7 - 99.7%
95% ConfidenceInterval
Sensitivity98.0%87.8 - 99.9%
Specificity100%99.4 - 99.9%
Correlation99.9%100 - 100%

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Broth Cultures

The performance of the SHIGA TOXIN QUIK CHEK test using overnight broth cultures (GN or MacConkey broth) from fecal specimens was compared to the Vero Cell Cytotoxin Assay (with neutralization). The following tables show a summary of the clinical performance of the Stx1 portion and the Stx2 portion of the SHIGA TOXIN QUIK CHEK test. The results show that the Stx1 portion exhibited a sensitivity of 100%, a specificity of 99.5%, and an overall correlation of 99.5% with cytotoxin assay. The Stx2 portion exhibited a sensitivity of 95.7%, a specificity of 99.9%, and an overall correlation of 99.6% with cytotoxin assay.

n = 770

Specificity

Correlation

Vero Cell Cytotoxin Assay
n = 770Stx 1 +Stx 1 -
STQCStx1 +424
STQCStx1 -0724
Broth Culture Testing Results
-------------------------------------
STQCStx2 +451
STQCStx2 -2722
Sensitivity95.7%95% ConfidenceInterval84.3-99.3%

Vero Cell Cytotoxin Assay

Stx 2 -

99.1 - 100%

99.6 - 99.6%

Stx 2 +

99.9% 99.6%

95% ConfidenceInterval
Sensitivity100%89.6 - 100%
Specificity99.5%98.5 - 99.8%
Correlation99.5%99.5 - 99.5%
Reproducibility

The reproducibility of the SHIGA TOXIN QUIK CHEK test was determined using 12 fecal specimens that were coded to prevent their identification during testing. Testing was performed at 2 independent laboratories and on-site at TECHLAB®, Inc. The samples were tested, twice a day over a 5-day period by multiple technicians at each site using 2 different kit lots. A positive and negative control was run with each panel of the masked samples. The results from each laboratory were submitted to TECHLAB®, Inc. and compared with in-house results. The results were consistent among the different locations, and exhibited a correlation of 100%. The samples produced the expected results 100% of the time.

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Analytical Sensitivity

The cutoff for the SHIGA TOXIN QUIK CHEK test was established at concentrations of 0.04 ng/mL Stx1 and 0.04 ng/mL Stx2.

Determination of Limitation of Detection (LOD) - cutoff points for Stx1 and Stx2 directly from fecal specimens:

The data below was determined following EP17A - "Protocols for Determination of Limits of Detection and Limits of Quantitation: Approved Guideline".

The cutoff point for Stx1 was determined by using highly purified Stx1, and was defined as the concentration of toxin which yielded positive results 95% of the time, and negative results 5% of the time. The cutoff point was determined empirically by testing dilutions of Sb1 in a negative fecal pool. in replicates of 20. Using this method. the cutoff was found to be 0.042 ng/mL. A concentration of 0.025 ng/mL was positive 50% of the time, and a concentration of 0.022 ng/mL was negative 95% of the time.

The cutoff point for Stx2 was determined by using highly purified Stx2, and was defined as the concentration of toxin which yielded positive results 95% of the time, and negative results 5% of the time. The cutoff point was determined empirically by testing dilutions of Stx2 in a negative fecal pool, in replicates of 20. Using this method, the cutoff was found to be 0.039 ng/mL. A concentration of 0.025 ng/mL was positive 50% of the time, and a concentration of 0.013 ng/mL was negative 95% of the time.

Determination of Limitation of Detection (LOD) - cutoff points for Stx1 and Stx2 from broth cultures:

The cutoff point for Stx1 was determined by using highly purified Stx1, and was defined as the concentration of toxin which yielded positive results 95% of the time, and negative results 5% of the time. The cutoff point was determined empirically by testing dilutions of Stx1 in overnight GN broth culture of non-toxin producing E. Coli 0157 (ATCC 04388), in replicates of 20. Using this method, the cutoff was found to be 0.042 ng/mL. A concentration of 0.025 ng/mL was positive 50% of the time, and a concentration of 0.010 ng/mL was negative 95% of the time.

The cutoff point for Stx2 was determined by using highly purified Stx2, and was defined as the concentration of toxin which yielded positive results 95% of the time, and negative results 5% of the time. The cutoff point was determined empirically by testing dilutions of Stx2 in overnight GN broth culture of non-toxin producing E. Coli 0157 (ATCC 04388), in replicates of 20. Using this method, the cutoff was found to be 0.039 ng/ml.. A concentration of 0.025 ng/mL was positive 50% of the time, and a concentration of 0.013 ng/mL was negative 95% of the time.

In conclusion, the data generated for Determination of Limitation of Detection (LOD). support Package Insert claims of analytical sensitivity for Stx1 at 0.04 ng/mL and Stx2 at 0.04 ng/mL.

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Analytical Specificity (Cross Reactivity)

The SHIGA TOXIN QUIK CHEK test.was evaluated for cross-reactivity with the bacterial and viral strains listed below. None of the strains were shown to interfere with the performance SHIGA TOXIN QUIK CHEK test.

  • Aeromonas hydrophila Campylobacter jejuni Clostridium difficile Enterococcus faecalis Escherichia coll EIEC (enteroinvasive) Escherichia fergusonii Helicobacter pylori Proteus vulgaris Pseudomonas fluorescens Serratia liquefacians Staphylococcus aureus Yersinia enterocolitica
    Human Adenovirus, Type 2, 14, 40 and 41 Human Coxsackievirus A9, B1 Feline calicvirus

Escherichia coli (non-toxigenic) Escherichia coli EPEC (enteropathogenic) Escherichia coli ETEC (enterotoxic) Eschenchia hermannii Klebsiella pneumoniae Providencia stuartii Salmonella enteric serovar minnesota Shigella flexneri Staphylococcus aureus (Cowan)

Campylobacter coli Candida albicans

Human rotavirus

Clostridium perfringens

Campylobacter fetus Citrobacter freundii Enterobacter cloacae Escherichia coli 0157:H7 (non-toxigenic) Gardnerella vaginalis Lactobacillus acidophilus Pseudomonas aeruginosa Salmonella typhimurium Shigella sonnei Staphylococcus epidermidis

Human Enterovirus 69

Strains/Serotypes

Various E. coli Shiga toxin-producing strains and serotypes were tested in the SHGA TOXIN QUIK CHEK test by both the Sorbitol MacConkey Agar (SMAC) plate and MacConkey broth culture methods. Escherichia coli 0157 strains were also tested using CT-SMAC and ChromAgar 0157 plate cultures. Each strain is a clinical isolate and each was tested by a cytotoxin assay and by a polymerase chain reaction (PCR) to confirm the presence of the Shiga toxin gene(s). All organisms generated positive results for the appropriate toxin(s) when tested. Following is a list of the serotypes tested, the number of strains tested in that group type and the type of toxin produced by each strain.

Shiga Toxin Type Stx1: Strain Types - O26:H11 (5 strains), O157:H7, O111:NM (2 strains), 0111a:NM, 0103:H2, O103:H25, O103:H6, O103:N, O111:H11, O111:H8, O145:H16, 0145:NM, 045:H2 (4 strains), 045:NM, 0125:NM, 0146:H21, 0156:H21, 026, 05:N, 070:H11

Shiga Toxin Type Stx2: Strain Types - O26:H11, O157:H7 (4 strains), O157:NM, O8:H19 (2 strains), O8:H10, ORU:H29, O177:NM, O6:H10, O104:H4 (European 2011 outbreak strain), 0121:H19 (3 strains), O121, O145:H28, O145, O113:H21, O104:H21, O55:H7, O91:H21

Shiga Toxin Type Stx1 and Stx2: Strain Types - O157:H7 (7 strains), O157:NM (2 strains), 0111:H8, O111, O111:NM, O113:H21

Interfering Substances (U.S. Formulations)

The following substances had no effect on positive or negative test results analyzed at the concentrations indicated: Hog gastric mucin (3.5% w/v), Human blood (40% v/v), Barium suffate (5% w/v), Imodium® (5% v/v), Kaopectate® (5% v/v), Pepto-Bismol® (5% v/v), Maalox® Advanced (5% v/v) Steric/Palmitic Acid (40% w/v), Metronidazole (0.25% w/v), Vancomycin (0.25% w/v), Priolsec OTC® (5 µg/mL), TUMS (50 µg/mL), Tagamet® (5 µg/mL), Leukocytes (0.05% v/v), Ciprofloxacin (0.25% w/v).

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Interference from High Analyte Concentrations

A study was performed to ensure that a high concentration of Stx1 toxin does not interfere with the detection of Stx2 toxin, or high concentrations of Stx2 toxin do not interfere with the detection of Stx1 toxin. Low and high concentrations were based on either 100x (high) or 3x (low) concentrations of Stx1 and Stx2 toxin. Low samples were prepared by spiking a negative fecal pool with 3x the 95% cutoff (LOD) for either toxin. High samples were prepared by spiking a negative fecal pool with 100x the 95% cutoff for either toxin. Testing was performed in triplicate according to the Package Insert instructions for direct testing. The results demonstrated that elevated levels of one analyte did not affect the detection of the other analyte.

Precision - Intra-Assay

For the determination of intra-assay performance, 6 positive fecal specimens (two positive for Stx1, two positive for Stx2, two positive for both Stx1 and Stx2) and six negative fecal specimens were analyzed. Each specimen was assayed on 5 cassettes. All positives remained positive and all negatives remained negative.

Precision - Inter-Assay

The inter-assay precision of the SHIGA TOXIN QUIK CHEK test was determined using 12 fecal specimens (six negative, two positive for Stx1. two positive for Stx2. and two positive for both Stx1 and Stx2). The samples were tested, twice a day over a 5-day period using 2 different kit lots. A positive and negative control was run on each day. All positives remained positive and all negatives remained negative.

Conclusion

The information submitted in this premarket notification is complete and supports a substantial equivalence decision.

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/9/Picture/1 description: The image shows the seal of the U.S. Department of Health & Human Services. The seal features a stylized eagle-like emblem with outstretched wings, symbolizing protection and care. Encircling the emblem are the words "DEPARTMENT OF HEALTH & HUMAN SERVICES • USA", indicating the department's name and national affiliation. The text is arranged in a circular fashion around the emblem.

Public Health Service

Food and Drug Administration 10903 New Hampshire Avenue Silver Spring, MD 20993

TECHLAB®, Inc. c/o Donna T. Link Director of QA, Regulatory & Compliance 2001 Kraft Drive Blacksburg, VA 24060-6358

Re: K121364

Trade/Device Name: SHIGA TOXIN QUIK CHEK Regulation Number: 21 CFR 866.3255 Regulation Name: Escherichia coli serological reagents Regulatory Class: Class I Product Code: GMZ Dated: September 26, 2012 Received: September 26, 2012

Dear Ms. Link:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into class II (Special Controls), it may be subject to such additional controls. Existing major regulations affecting your device can be found in Title 21, Code of Federal Regulations (CFR), Parts 800 to 895. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); and good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820). This letter will allow you to begin marketing your device as described in your Section 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed

OCT
2 2012

{10}------------------------------------------------

Page 2 - Donna T. Link

predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Parts 801 and 809), please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at (301) 796-5450. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to

http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html.

Sincerely yours.

Ulue Self for

Sally A. Hojvat, M.Sc., Ph.D. Director Division of Microbiology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health

Enclosure

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INDICATIONS FOR USE 2.

510(k) Number: K121364

SHIGA TOXIN QUIK CHEK Device Name:

Indications For Use:

The SHIGA TOXIN QUIK CHEK test is a rapid membrane enzyme immunoassay for the simultaneous qualitative detection and differentiation of Shiga toxin 1 (Stx1) and Shiga toxin 2 (Stx2) in a single test device. It is intended for use with human fecal samples from patients with gastrointestinal symptoms to aid in the diagnosis of disease caused by Shiga toxin producing Escherichia coli (STEC). It may be used with fecal specimens, or broth or plate cultures derived from fecal specimens. The test results should be considered in conjunction with the patient history.

FOR IN VITRO DIAGNOSTIC USE.

Prescription Use _ (Part 21 CFR 801 Subpart D) AND/OR

Over-The-Counter Use (21 CFR 807 Subpart C)

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Concurrence of CDRH, Office of In Vitro Diagnostic Devices (OIVD)

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Division Sign-off Office of In Vitro Diagnostic Device Evaluation and Safety

510(k)_ K 121364

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§ 866.3255

Escherichia coli serological reagents.(a)
Identification. Escherichia coli serological reagents are devices that consist of antigens and antisera used in serological tests to identifyEscherichia coli from cultured isolates derived from clinical specimens. Additionally, some of these reagents consist ofEscherichia coli antisera conjugated with a fluorescent dye used to identifyEscherichia coli directly from clinical specimens or cultured isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by this bacterium belonging to the genusEscherichia, and provides epidemiological information on diseases caused by this microorganism. AlthoughEscherichia coli constitutes the greater part of the microorganisms found in the intestinal tract in humans and is usually nonpathogenic, those strains which are pathogenic may cause urinary tract infections or epidemic diarrheal disease, especially in children.(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 the limitations in § 866.9.