K Number

Device Name

ARTUS C. DIFFICILE QS-RGQ MDX KIT

Manufacturer

QIAGEN, GMBH

Date Cleared

2014-04-04

(102 days)

Product Code

OZN OOI

Regulation Number

866.3130

Intended Use

The artus C. difficile QS-RGQ MDx Kit is an in vitro polymerase chain reaction (PCR) assay for use on the QIAsymphony RGQ MDx system for the qualitative detection of toxigenic Clostridium difficile toxin A and toxin B genes in human liquid or soft stool specimens from patients suspected of having Clostridium difficile associated disease. The test is intended to be used directly on patient samples. The artus C. difficile QS-RGQ MDx Kit is intended to be used to aid in diagnosis of Clostridium difficile infection.

Device Description

The artus C. difficile QS-RGQ MDx Kit assay uses PCR to generate an amplified product from the tcdA and tedB/tedBv genes of toxigenic C. difficile DNA in clinical specimens. Samples are extracted and prepared using the Q1Asymphony SP instrument with the QIAsymphony DSP Virus/Pathogen Mini Kit, followed by assay setup on the OIAsymphony AS. Amplification and detection are carried out using the artus C. difficile OS-RGQ MDx Kit with the Rotor-Gene Q MDx (RGQ MDx) and Rotor-Gene AssayManager software. The presence of a toxigenic C. difficile target sequence is indicated by the fluorescent signal generated through the use of fluorescently labeled oligonucleotide probes. The probes do not generate a signal unless they are specifically bound to the amplified product. The amplification cycle at which fluorescent signal is detected by the RGQ MDx is inversely proportional to the toxigenic C. difficile DNA target concentration present in the original specimen. A bacterial species unrelated to toxigenic C. difficile is introduced into each specimen during sample preparation to serve as an internal control. The internal control bacteria are lysed simultaneously with toxigenic C. difficile in the specimen. and amplified in the same reaction as the C. difficile targets using PCR, and serve to demonstrate that the entire assay process has proceeded correctly for each specimen.

More Information

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Type

Center

Panel

Date Received

Product Code

Subsequent Product Codes

Applicant Name (Manufacturer)

Device Name

Decision

Street 1

Street 2

City

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Country Code

ZIP

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Class Advise Committee

SSP Indicator

Third Party Reviewed

Expedited Review

Predicate Devices

K123998

Reference Devices

Not Found

AI/ML (Artificial Intelligence / Machine Learning)

No
The device description and performance studies focus on standard PCR technology and data analysis based on fluorescent signal detection and threshold cycles (Ct values). There is no mention of AI or ML algorithms being used for interpretation or analysis.

Therapeutic

No.
Explanation: This device is an in vitro diagnostic (IVD) PCR assay used to detect specific genes of toxigenic Clostridium difficile in stool specimens, aiding in diagnosis. It does not provide any treatment or therapeutic intervention.

Diagnostic

Yes
The "Intended Use / Indications for Use" section explicitly states, "The artus C. difficile QS-RGQ MDx Kit is intended to be used to aid in diagnosis of Clostridium difficile infection."

SaMD (Software as a Medical Device)

The device is an in vitro diagnostic (IVD) kit that includes reagents and is used with specific hardware (QIAsymphony RGQ MDx system, QIAsymphony SP instrument, QIAsymphony AS, Rotor-Gene Q MDx) for sample preparation, amplification, and detection. While it uses software (Rotor-Gene AssayManager software) for analysis, it is not solely software.

IVD (In Vitro Diagnostic)

Yes, this device is an IVD (In Vitro Diagnostic).

Here's why:

Intended Use: The "Intended Use / Indications for Use" section explicitly states that the artus C. difficile QS-RGQ MDx Kit is an "in vitro polymerase chain reaction (PCR) assay". It is intended for the qualitative detection of specific genes in human stool specimens to aid in the diagnosis of Clostridium difficile infection. This clearly aligns with the definition of an in vitro diagnostic device, which is used to examine specimens taken from the human body to provide information for diagnosis, monitoring, or treatment.
Device Description: The description details how the assay works by analyzing DNA from a human specimen (stool) using PCR, which is a common in vitro diagnostic technique.
Clinical Performance Study: The document includes a clinical performance study comparing the device's results to established methods (culture) using human specimens. This is a standard requirement for demonstrating the performance of an IVD.

PCCP (Predetermined Change Control Plan) Authorized

N/A

Overview

Intended Use / Indications for Use

The artus C. difficile QS-RGQ MDx Kit is intended to be used to aid in diagnosis of Clostridium difficile infection.

Product codes (comma separated list FDA assigned to the subject device)

OZN, OOI

Device Description

Mentions image processing

Not Found

Mentions AI, DNN, or ML

Not Found

Input Imaging Modality

Not Found

Anatomical Site

Not Found

Indicated Patient Age Range

Not Found

Intended User / Care Setting

Not Found

Description of the training set, sample size, data source, and annotation protocol

Not Found

Description of the test set, sample size, data source, and annotation protocol

Not Found

Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)

Analytical Sensitivity (Limit of detection):
Assessed using 3 toxigenic C. difficile strains (NAP-1/BI/027, 1470, VPI 10463). LoD defined as the bacterial titer (CFU/mL) detected with >=95% probability, determined by probit analysis.

C. difficile NAP1 (ATCC BAA-1870, strain:4118): LoD 7.9 CFU/mL (95%CI 6.1-15.0)
C. difficile 1470 (ATCC 43598, strain:1470): LoD 11.2 CFU/mL (95%CI 8.7-16.8)
C. difficile 10463 (ATCC 43255, strain:10463): LoD 2.8 CFU/mL (95%CI 2.1-4.2)

Analytical Reactivity:

Tested 27 toxigenic C. difficile strains and characterized clinical isolates diluted in TE buffer to 2-3x LoD of the reference strain.
Result: C. difficile target was detected in all strains tested.

Cross-Reactivity and Microbial Interference:

Tested a panel of microorganisms (bacteria, fungi, viruses) and human genomic DNA.
Organisms were tested at approx. 1 x 10^8 CFU/ml for bacteria/fungi or >=1 x 10^5 units/ml for viruses in the presence of 2-3x LoD of three C. difficile strains (NAP-1/BI/027, VPI 10463).
Result: None of the potential interfering organisms cross-reacted or interfered with the detection of any of the 3 C. difficile strains. In silico analysis for Clostridium botulinum predicted no cross-reactivity or microbial interference.

Precision:
(a) Within Laboratory Repeatability Study:

Study Type: Repeatability study.
Sample Size: 7-member panel (2 C. difficile strains: NAP-1/BI/027 and 1470) at 3 concentrations (positive, low positive, high negative) and a negative member.
Key Results: Tested in replicates of three, once a day for 12 days (262 data points). Conducted by two operators using one instrument and one reagent kit lot.
Key Metrics (Mean Ct, STDEV, %CV):
- NAP1 Positive: IC (29.78, 0.49, 1.64%), tcdA (30.84, 0.47, 1.52%), tcdB (33.58, 0.64, 1.91%)
- NAP1 Low Positive: IC (30.07, 0.55, 1.82%), tcdA (32.19, 0.99, 3.08%), tcdB (34.92, 0.68, 1.94%)
- NAP1 High Negative: IC (29.99, 0.72, 2.41%), tcdA (34.21, 0.91, 2.66%), tcdB (36.18, 0.23, 0.64%)
- 1470 Positive: IC (29.85, 0.52, 1.73%), tcdA (30.95, 0.55, 1.78%), tcdB (33.72, 0.45, 1.33%)
- 1470 Low Positive: IC (29.89, 0.41, 1.39%), tcdA (32.14, 0.65, 2.03%), tcdB (35.13, 0.63, 1.80%)
- 1470 High Negative: IC (29.92, 0.53, 1.76%), tcdA (34.14, 0.66, 1.92%), tcdB (36.39, 0.03, 0.07%)
- Negative: IC (30.00, 0.44, 1.46%)

(b) Site-to-Site Reproducibility Study:

Study Type: Reproducibility study.
Sample Size: 7-member panel (as above).
Key Results: Run by 2 users at each of 3 sites (IMDx and 2 external sites). Each user performed 5 runs on alternating days. Panel members tested in replicates of 3, randomized and blinded. A single QIAsymphony RGQ instrument system and one lot of the kit used at each site.
Key Metrics (Mean Ct, SD, %CV for overall):
- NAP-1/B1/027 Positive: IC (30.58, 0.42, 1.37%), tcdA (32.00, 0.80, 2.49%), tcdB (34.53, 0.76, 2.19%)
- NAP-1/B1/027 Low Positive: IC (30.74, 0.55, 1.78%), tcdA (33.24, 0.79, 2.38%), tcdB (35.36, 0.62, 1.76%)
- NAP-1/B1/027 High Negative: IC (30.65, 0.39, 1.27%), tcdA (34.19, 0.45, 1.32%), tcdB (35.91, 0.16, 0.43%)
- 1470 Positive: IC (30.74, 0.42, 1.35%), tcdA (31.92, 0.88, 2.77%), tcdB (34.78, 0.69, 1.99%)
- 1470 Low Positive: IC (30.65, 0.4, 1.31%), tcdA (33.2, 0.96, 2.9%), tcdB (35.65, 0.53, 1.48%)
- 1470 High Negative: IC (30.58, 0.46, 1.49%), tcdA (34.49, 0.31, 0.91%), tcdB (36.12, 0.42, 1.16%)
- Negative: IC (30.67, 0.42, 1.36%)

Target Carryover Study:

Study Type: Carryover study.
Key Results: 5 runs with alternating high positive (concentration exceeding 95% of specimens from diseased patients in intended use population) and negative samples.
Key Metrics: Carryover rate of 0.0%.

Interfering Substances:

Study Type: Interference study.
Key Results: Tested a panel of 23 substances (e.g., anti-fungal, creams, antacids, antibiotics, blood, fecal components) at physiologically relevant concentrations. Three toxigenic C. difficile strains (NAP-1/BI/027, 1470, VPI 10463) were diluted to 2-3x LoD and spiked with each substance.
Result: None of the substances showed an inhibitory effect on the detection of C. difficile.

Clinical Studies:

Study Type: Clinical performance evaluation.
Sample Size: 759 liquid or soft stool specimens initially, 741 specimens with valid results included in final analysis.
Data Source: 3 external testing sites using C. difficile patient samples from 5 geographically diverse locations within the United States in 2013.
Comparison: Compared to direct and/or enriched culture.

(a) Assay vs. Enriched Culture Comparison:

Sample Size: 741 specimens.
Key Results:
- Positive: artus C. difficile QS-RGQ MDx Kit 131 (114 True Positives, 17 False Positives)
- Negative: artus C. difficile QS-RGQ MDx Kit 610 (13 False Negatives, 597 True Negatives)
- Discordant Analysis:
  - 17 artus Positive / Enriched Culture Negative: 12/17 were positive for toxigenic C. difficile by alternative PCR + sequencing, agreeing with artus.
  - 13 artus Negative / Enriched Culture Positive: 10/12 were negative for toxigenic C. difficile by alternative PCR + sequencing, agreeing with artus (1 specimen unavailable).

(b) Assay vs. Direct Toxigenic Culture Comparison:

Sample Size: 699 specimens.
Key Results:
- Positive: artus C. difficile QS-RGQ MDx Kit 105 (84 True Positives, 21 False Positives)
- Negative: artus C. difficile QS-RGQ MDx Kit 594 (1 False Negative, 593 True Negatives)
- Discordant Analysis:
  - 19 artus Positive / Direct Culture Negative: 14/19 were positive for toxigenic C. difficile by alternative PCR + sequencing, agreeing with artus (2 specimens unavailable).
  - 1 artus Negative / Direct Culture Positive: 1 specimen unavailable for testing.

Key Metrics (Sensitivity, Specificity, PPV, NPV, etc.)

Assay vs. Enriched Culture Comparison:

Sensitivity: 90% (95% CI: 83%-94%)
Specificity: 97% (95% CI: 96%-98%)
Positive Predictive Value: 87% (95% CI: 80%-92%)
Negative Predictive Value: 98% (95% CI: 96%-99%)
Prevalence: 17% (95% CI: 15%-20%)

Assay vs. Direct Toxigenic Culture Comparison:

Sensitivity: 99% (95% CI: 94%-100%)
Specificity: 97% (95% CI: 95%-98%)
Positive Predictive Value: 80% (95% CI: 71%-87%)
Negative Predictive Value: 100% (95% CI: 99%-100%)
Prevalence: 12% (95% CI: 10%-15%)

Predicate Device(s): If the device was cleared using the 510(k) pathway, identify the Predicate Device(s) K/DEN number used to claim substantial equivalence and list them here in a comma separated list exactly as they appear in the text. List the primary predicate first in the list.

K123998

Reference Device(s): Identify the Reference Device(s) K/DEN number and list them here in a comma separated list exactly as they appear in the text.

Not Found

Predetermined Change Control Plan (PCCP) - All Relevant Information for the subject device only (e.g. presence / absence, what scope was granted / cleared under the PCCP, any restrictions, etc).

Not Found

Regulation Number and Section

§ 866.3130 Clostridium difficile toxin gene amplification assay.

(a)
Identification. AClostridium difficile toxin gene amplification assay is a device that consists of reagents for the amplification and detection of target sequences inClostridium difficile toxin genes in fecal specimens from patients suspected of havingClostridium difficile infection (CDI). The detection of clostridial toxin genes, in conjunction with other laboratory tests, aids in the clinical laboratory diagnosis of CDI caused byClostridium difficile. (b)
Classification. Class II (special controls). The special controls are set forth in FDA's guideline document entitled: “Class II Special Controls Guideline: Toxin Gene Amplification Assays for the Detection ofClostridium difficile; Guideline for Industry and Food and Drug Administration Staff.” See § 866.1(e) for information on obtaining this document.

Summary

QIAGIEN artus® C. difficile QS-RGQ MDx Kit Attachment 1. Revised 510(k) Summary

510(k) Submission K 133936 Amendment Page 1 of 15

510(k) SUMMARY

General Information

| Submitted by: | QIAGEN GmbH
Qiagen Strasse 1
Hilden, Germany D-40724 |

---------------	------------------------------------------------------------

Contact Person:

Kimberly Mapp, Ph.D. Manager, Regulatory Affairs 1201 Clopper Road Gaithersburg, MD 20878

Phone: 301.944.7817 Fax: 240.686.3847 Email: kimberly.mapp(@qiagen.com

April 4, 2014 Date Prepared:

Device Name:

artus® C. difficile QS-RGQ MDx Kit

artus® C. difficile QS-RGQ MDx Kit Trade Name: Common Name: C. difficile nucleic acid amplification test assay Classification: Class II

Predicate Device

Manufacturer	Product Name	510(k) No.
Quidel	Quidel Molecular Direct C. difficile Assay	K123998

Device Description

APR 0 4 2014

QIAGEN	510(k) Submission
artus® C. difficile QS-RGQ MDx Kit	K133936 Amendment
Attachment 1, Revised 510(k) Summary	Page 2 of 15

detected by the RGQ MDx is inversely proportional to the toxigenic C. difficile DNA target concentration present in the original specimen. A bacterial species unrelated to toxigenic C. difficile is introduced into each specimen during sample preparation to serve as an internal control. The internal control bacteria are lysed simultaneously with toxigenic C. difficile in the specimen. and amplified in the same reaction as the C. difficile targets using PCR, and serve to demonstrate that the entire assay process has proceeded correctly for each specimen.

Intended Use

The artus C. difficile QS-RGQ MDx Kit is an in vitro polymerase chain reaction (PCR) assay for use on the OlAsymphony RGO MDx system for the qualitative detection of toxigenic Clostridium difficile toxin A and toxin B genes in human liquid or soft stool specimens from patients suspected of having Clostridium difficile associated disease. The test is intended to be used directly on patient samples.

The artus C. difficile QS-RGQ MDx Kit is intended to be used to aid in diagnosis of Clostridium difficile infection.

Comparison of the artus® C. difficile QS-RGQ MDx Kit and the Predicate Device

The artus® C. difficile QS-RGQ MDx Kit is substantially equivalent to the predicate device:

· K123998: Ouidel Molecular Direct C. difficile Assay
Similarities and differences between the artus® C. difficile QS-RGQ MDx Kit (72) and the predicate device are shown in Table 1.

Table 1: Comparison of the artus® C. difficile QS-RGQ MDx Kit with the predicate device.

Characteristic	Device	Predicate
Name	artus C. difficile QS-RGQ MDx Kit	Quidel Molecular Direct C. difficile Assay
510(k) No.	TBD	K123998
Regulation	866.3130	866.3130
Product Code	OZN	OZN
Device Class	Class II	Class II
Similarities
Intended Use	The artus C. difficile QS-RGQ MDx Kit is an in vitro polymerase chain reaction (PCR) assay for use on the QIAsymphony RGQ MDx system for the qualitative detection of toxigenic Clostridium difficile toxin A and toxin B genes in human liquid or soft stool specimens from patients suspected of having Clostridium difficile associated disease. The test is intended to be used directly on patient samples. The artus C. difficile QS-RGQ MDx Kit is intended to be used to aid in diagnosis of Clostridium difficile infection.	The Quidel Molecular Direct C. difficile Assay is a qualitative, multiplexed in vitro diagnostic test for the direct detection of toxin A gene ( tcdA ) or toxin B gene ( tcdB ) sequences of toxigenic strains of Clostridium difficile from unformed (liquid or soft) stool specimens collected from patients suspected of having Clostridium difficile-Associated Disease (CDAD). The Quidel Molecular Direct C. difficile Assay is a real-time PCR test and utilizes proprietary sample preparation with fluorescently labeled primers and probes. The assay can be performed using either the Life Technologies QuantStudio® Dx; the Applied Biosystems 7500 Fast Dx, or the Cepheid SmartCycler II, to detect the toxin gene sequences associated with toxin-producing C. difficile strains. The assay is intended to be performed directly on CDAD-suspected stool specimens, and is indicated for use as an aid in the diagnosis of CDAD.
Specimen Type	Liquid or soft stool	Unformed (liquid or soft) stool
Characteristic	Device	Predicate
Assay Targets	Toxin A gene ( tcdA )
Toxin B gene ( tcdB and tcdBv )	Toxin A gene ( tcdA )
Toxin B gene ( tcdB )
Amplification and Detection Technology	Real-time PCR DNA
amplification	Real-time PCR DNA
amplification
Differences
Assay Controls	Positive Control, Negative Control and Internal Control included in the kit.	Process Control included in the kit.
Positive and Negative Controls not included in kit; separate control kit available for sale.
Nucleic Acid Extraction and Assay Setup	Assay uses the QIAsymphony SP/AS for automated sample preparation and assay setup.	Assay uses proprietary sample preparation buffer and manual assay setup.
Amplification and Detection Instrument System	Assay uses the Rotor-Gene Q MDx.	Assay can be performed using either the:
• Life Technologies QuantStudio Dx
• Applied Biosystems 7500 Fast Dx
• Cepheid SmartCycler II

The differences between the artus C. difficile QS-RGQ MDx Kit and Quidel Molecular Direct C. difficile assays are primarily centered around the control strategy and instrumentation. These differences do not affect substantial equivalency of the artus C. difficile QS-RGQ MDx Kit and the Quidel Molecular Direct C. difficile Assay. Both assays detect toxigenic C. difficile, and the assays have comparable intended uses. The differences noted above do not change the intended use and do not raise questions of safety and effectiveness.

Performance Characteristics - Non-Clinical Studies

Analytical Sensitivity (Limit of detection)

The limit of detection (LoD) was assessed for the artus C. difficile QS-RGQ MDx Kit using 3 toxigenic Clostridium difficile strains: NAP-1/BI/027 strain, toxinotype III A+B+ (ATCC® BAA-1870); 1470 strain, toxinotype VIII A-B+(ATCC 43598); and VPI 10463 strain, toxinotype 0 A+B+ (ATCC 43255). The LoD is defined as the toxigenic C. difficile bacterial titer (CFU/mL) detected with a probability of 95% or greater and was determined by probit analysis. The results, representative of the analytical sensitivity of the artus C. difficile QS-RGQ MDx Kit, are summarized in Table 2.

Table 2: Limit of Detection

Strain	LoD (95%CI)
C. difficile NAP1
ATCC BAA-1870, strain:4118	7.9 CFU/mL (6.1-
15.0)
C. difficile 1470
ATCC 43598, strain:1470	11.2 CFU/mL (8.7-
16.8)
C. difficile 10463
ATCC 43255, strain:10463	2.8 CFU/mL (2.1-
4.2)

Analytical Reactivity

The analytical reactivity of the artus C. difficile QS-RGQ MDx Kit was assessed to determine whether the kit could detect a broad range of toxigenic C. difficile strains representing temporal and geographical diversity. A total of 27 strains and characterized clinical isolates were diluted in TE buffer to 2-3x LOD of the reference strain and tested with the artus C. difficile QS-RGQ MDx Kit. C. difficile target was detected in all strains tested Table 3.

Name	Strain	Toxinotype	Origin
ATCC 17857	870	O	unknown
ATCC 17858	1253	N/A	unknown
ATCC 43594	W1194	N/A	Human feces; Belgium
ATCC 43596	545	N/A	Human feces; Belgium
ATCC 43599	2022	N/A	Human feces; Belgium
ATCC 43600	2149	N/A	Human feces; Belgium
ATCC 51695	BDMS
18AN	N/A	Becton Dickinson
Microbiology Systems,
Johns Hopkins Univ.
Hosp. Lab
ATCC 700792	14797-2	N/A	Human feces;
Michigan, USA
ATCC 9689	90556-
M6S	O	unknown
ATCC BAA-
1382	630	X	Switzerland
ATCC BAA-
1805	N/A	III	unknown
ATCC BAA-
1871	4111	O	Human; New Jersey,
USA
ATCC BAA-
1872	4206	O	Human; Maine, USA
ATCC BAA-
1873	5283	O	Human; New York,
USA
ATCC BAA-
1874	4205	O	Human; Oregon, USA
ATCC BAA-
1875	5325	V	Human; Georgia, USA
ATCC BAA-
2155	LBM
0801058	N/A	Human; New Mexico,
USA
ATCC BAA-
2156	LBM
0801040	N/A	Human; Cambridge
UK
CCUG 20309	8864	X	Birmingham, UK
Illinois VA
Hospital isolate
278	N/A	II	Illinois, USA
Illinois VA
Hospital isolate
464	N/A	IV	Illinois, USA
Illinois VA
Hospital isolate	N/A	VIII	Illinois, USA
Name	Strain	Toxinotype	Origin
4092
Illinois VA
Hospital isolate
5572	N/A	VIII	Illinois, USA
Illinois VA
Hospital isolate
3430	N/A	IX	Illinois, USA
Illinois VA
Hospital isolate
1753	N/A	XII	Illinois, USA
Illinois VA
Hospital isolate
5090	N/A	XXI	Illinois, USA
Illinois VA
Hospital isolate
3130	N/A	XXII	Illinois, USA

Table 3: Strains Tested in Analytical Reactivity

Cross-Reactivity and Microbial Interference

A panel of microorganisms that may be present in patient specimens was tested to determine whether these microorganisms interfered with the detection of tcdA or tedB targets or were cross-reactive with the artus C. difficile QS-RGQ MDx Kit. Organisms were tested at a target concentration of approximately 1 x 10° CFU/ml for bacteria and fungi or ≥1 x 105 units/ml for viruses separately in the presence of 2-3x LOD of each of three C. difficile strains: NAP-1/BI/027 strain, and VPI 10463 strain. None of the potential interfering organisms cross-reacted or interfered with the detection of any of the 3 C. difficile strains by the artus C. difficile QS-RGQ MDx Kit (Table 4). Crossreactivity for Clostridium botulinum was analyzed in silico and predicted no cross reactivity or microbial interference for the artus C. difficile QS-RGQ MDx Kit.

Table 4: Organisms Tested in Cross Reactivity and Microbial Interference
--------------------------------------------------------------------------	--	--	--

Organism Tested	Source ID
Abiotrophia defectiva	ATCC 49176
Acinetobacter baumannii	ATCC 19606
Aeromonas hydrophila	ATCC 7966
Alcaligenes faecalis subsp. faecalis	ATCC 15554
Bacillus cereus	ATCC 13472
Bacteroides fragilis	ZMC 0601533
Organism Tested	Source ID
Campylobacter coli	ATCC 43479
Campylobacter coli	ATCC 33559
Campylobacter jejuni subsp. jejuni	ATCC 33292
Candida albicans	ATCC 10231
Citrobacter freundii	ATCC 8090
Clostridium bifermentans	ATCC 638
Clostridium butyricum	ATCC 19398
Clostridium haemolyticum	ATCC 9650
Clostridium novyi	ATCC 19402
Clostridium orbiscindens	ATCC 49531
Clostridium perfringens	ATCC 13124
Clostridium scindens	ATCC 35704
Clostridium septicum	ATCC 12464
Clostridium sordellii	ATCC 9714
Clostridium difficile (non-toxigenic)	ATCC 43593
Clostridium difficile (non-toxigenic)	ATCC 43601
Clostridium sporogenes	ATCC 15579
Edwardsiella tarda	ATCC 15947
Enterobacter aerogenes	ATCC 13048
Enterobacter cloacae	ATCC 13047
Enterococcus faecalis (vanB)	ATCC 51299
Escherichia coli	ATCC 23511
Escherichia coli 0157:H7	ATCC 700927
Helicobacter pylori DNA	ATCC 43504D-5
Klebsiella oxytoca	ATCC 33496
Lactobacillus acidophilus	ATCC 4356
Listeria monocytogenes	ZMC 0801534
Peptostreptococcus anaerobius	ATCC 27337
Plesiomonas shigelloides	ATCC 14029
Porphyromonas asaccharolytica	ATCC 25260
Prevotella melaninogenica	ATCC 25845
Proteus mirabilis	ATCC 25933
Providencia alcalifaciens	ATCC 9886
Pseudomonas aeruginosa	ATCC 35554
Salmonella choleraesuis (Typhimurium)	ATCC 14028
Salmonella enterica subsp. arizonae	ATCC 13314
Salmonella enterica subsp. enterica	ATCC 7001
Serratia liquefaciens	ATCC 27592
Serratia marcescens	ATCC 13880
Shigella boydii	ATCC 9207
Shigella dysenteriae	ATCC 11835
Organism Tested	Source ID
Shigella sonnei	ATCC 29930
Staphylococcus aureus	ATCC 43300
Staphylococcus epidermidis	ATCC 14990
Streptococcus agalactiae	ATCC 27541
Vibrio parahaemolyticus	ATCC 17802
Adenovirus	ZMC 0810110 CF
Rotavirus	ZMC 0810041 CF
Norovirus	ZMC 0810086 CF
Enterovirus	ZMC 0810047 CF
Echovirus	ZMC 0810023 CF
Coxsackie virus	ZMC 0810075 CF
Cytomegalovirus	ZMC 0810003 CF
Human Genomic DNA	Promega G3041

510(k) Submission K 133936 Amendment Page 9 of 15

Precision

The precision of the artus C. difficile QS-RGQ Kit was assessed using a 7-member panel consisting of 2 C. difficile strains: NAP-1/BI/027 strain, toxinotype III A+B+ (ATCC BAA-1870) and 1470 strain, toxinotype VIII A-B+(ATCC 43598). Panel members were initially diluted in TE buffer then tested in Buffer ATL containing negative stool matrix with a single strain present (NAP-1/B1/027 or 1470) at 3 concentrations; positive (approximately 2-3x LoD), low positive (1x LoD), and high negative (tcdA | | | tcdB | | |
|-----------------------|------------------|-------|-------|-------------|-------|-------|-------------|-------|-------|
| | MEAN | STDEV | %CV | MEAN | STDEV | %CV | MEAN | STDEV | %CV |
| NAP1 Positive | 29.78 | 0.49 | 1.64% | 30.84 | 0.47 | 1.52% | 33.58 | 0.64 | 1.91% |
| NAP1 Low
Positive | 30.07 | 0.55 | 1.82% | 32.19 | 0.99 | 3.08% | 34.92 | 0.68 | 1.94% |
| NAP1 High
Negative | 29.99 | 0.72 | 2.41% | 34.21 | 0.91 | 2.66% | 36.18 | 0.23 | 0.64% |
| 1470 Positive | 29.85 | 0.52 | 1.73% | 30.95 | 0.55 | 1.78% | 33.72 | 0.45 | 1.33% |
| 1470 Low
Positive | 29.89 | 0.41 | 1.39% | 32.14 | 0.65 | 2.03% | 35.13 | 0.63 | 1.80% |
| 1470 High
Negative | 29.92 | 0.53 | 1.76% | 34.14 | 0.66 | 1.92% | 36.39 | 0.03 | 0.07% |
| Negative | 30.00 | 0.44 | 1.46% | N/A | N/A | N/A | N/A | N/A | N/A |

Table 5: Within Laboratory Repeatability Study Results

To measure site-to-site reproducibility, the 7-member panel was run by 2 users at each of 3 sites (IMDx and 2 external sites). Each of the 2 users performed 5 runs on alternating testing days. Panel members were tested in replicates of 3 that were randomized and blinded to the user. A single QlAsymphony RGQ instrument system and one lot of the artus C. difficile QS-RGQ Kit were used at each site to conduct the study (Table 6).

			Internal Control			tcdA			tcdB
Strain	Panel
Member	Site	Mean
Ct	SD	% CV	Mean
Ct	SD	%CV	Mean
Ct	SD	%CV
NAP-
1/B1/027	Positive	1	30.61	0.42	1.38	31.85	0.73	2.3	34.32	0.69	2.02
		2	30.58	0.51	1.65	32.16	0.8	2.5	34.43	0.71	2.05
		3	30.55	0.32	1.05	31.97	0.85	2.65	34.87	0.78	2.25
		overall	30.58	0.42	1.37	32.00	0.80	2.49	34.53	0.76	2.19
	Low
Positive	1	30.63	0.4	1.3	33.38	0.71	2.14	35.58	0.55	1.55
		2	30.73	0.6	1.94	33.27	0.81	2.45	35.01	0.53	1.52
		3	30.86	0.62	2	33.07	0.84	2.53	35.45	0.69	1.96
		overall	30.74	0.55	1.78	33.24	0.79	2.38	35.36	0.62	1.76
High
Negative	1	30.71	0.35	1.15	34.21	0.54	1.58	35.88	N/A	N/A
	2	30.59	0.33	1.09	34.21	0.29	0.86	35.92	N/A	N/A
	3	30.64	0.47	1.53	34.17	0.57	1.68	N/A	N/A	N/A
	overall	30.65	0.39	1.27	34.19	0.45	1.32	35.91	0.16	0.43

Table 6: Site-to-Site Reproducibility Study Results

QIAGEN artus® C. difficile QS-RGQ MDx Kit Attachment 1, Revised 510(k) Summary

510(k) Submission K 133936 Amendment Page 11 of 15

					Internal Control			tcdA			tcdB
Strain	Panel
Member	Site	Mean Ct	SD	Mean Ct	SD	% CV	Mean Ct	SD	%CV	Mean Ct	SD	%CV
1470	Positive	1	30.67	0.49	30.67	0.49	1.58	32.22	0.86	2.67	34.74	0.61	1.76
		2	30.69	0.41	30.69	0.41	1.32	31.74	0.95	2.99	34.66	0.74	2.14
		3	30.86	0.33	30.86	0.33	1.06	31.81	0.78	2.45	34.95	0.7	2.01
		overall	30.74	0.42	30.74	0.42	1.35	31.92	0.88	2.77	34.78	0.69	1.99
1470	Low Positive	1	30.74	0.42	30.74	0.42	1.37	33.17	0.94	2.83	35.61	0.49	1.38
		2	30.51	0.42	30.51	0.42	1.38	33.06	0.89	2.7	35.62	0.6	1.7
		3	30.7	0.33	30.7	0.33	1.08	33.41	1.08	3.22	35.77	0.46	1.29
		overall	30.65	0.4	30.65	0.4	1.31	33.2	0.96	2.9	35.65	0.53	1.48
	High Negative	1	30.76	0.46	30.76	0.46	1.5	34.64	0.14	0.4	36.41	N/A	N/A
		2	30.55	0.45	30.55	0.45	1.46	34.15	0.28	0.83	35.82	N/A	N/A
		3	30.44	0.42	30.44	0.42	1.38	34.63	0.27	0.77	N/A	N/A	N/A
		overall	30.58	0.46	30.58	0.46	1.49	34.49	0.31	0.91	36.12	0.42	1.16
	Negative	1	30.68	0.37	30.68	0.37	1.2	N/A	N/A	N/A	N/A	N/A	N/A
		2	30.66	0.47	30.66	0.47	1.55	N/A	N/A	N/A	N/A	N/A	N/A
		3	30.67	0.42	30.67	0.42	1.37	33.58	N/A	N/A	N/A	N/A	N/A
		overall	30.67	0.42	30.67	0.42	1.36	33.58	N/A	N/A	N/A	N/A	N/A

Target Carryover Study

Absence of carryover between samples for the entire workflow was proven by performing 5 runs with alternating high positive (formulated at a concentration which exceeded that of organisms found in 95% of specimens from diseased patients in the intended use population) and negative samples were detected correctly, generating a carryover rate of 0.0%.

Interfering Substances

A panel of 23 substances that may be present in patient specimens (Table 7) was tested to determine whether these substances interfered with the performance of the artus C. difficile QS-RGQ MDx Kit. Three toxigenic C. difficile strains: NAP-1/BI/027 strain, 1470 strain, and VPI 10463 strain, were diluted to approximately 2-3x LoD and spiked with each potentially inhibitory substance. None of the substances showed an inhibitory effect on the detection of C, difficile by the artus C. difficile QS-RGQ MDx Kit.

| Type | Substance Tested* |
|-------------------------------|--- | Anti-fungal nitrate cream | Miconazole nitrate | Cream/Suppos
itories | Preparation H | Cream/Suppos
itories | Zinc oxide | Cream/Suppos
itories | Vaseline | Anti-
hemorrhoid
creams | Hemorrhoid gel hydrochloride | 2% w/v | Condoms | Condoms | Moist
Towelettes | Moist Towelettes Chloride | 0.12% w/v | Antacids | Gaviscon Magnesium carbonate | 0.1 mg/mL | Antacids | Tums | Antacids | Tagamet | Antacids release) | Omeprazole
magnesium | 0.5 mg/mL | Enemas | Anti-Diarrheal
Medication | Imodium | Anti-Diarrheal
Medication | Pepto Bismol | Laxative | ExLax | Antibiotics | Antibiotics | Anti-
inflammatory | Naproxen (Aleve) | Naproxen Sodium | Blood enzymes, iron, etc., | 5% v/v | Fecal
Components | Mucus | Fecal
Components | Palmitic acid | Fecal
Components | Stearic acid | MRI Contrast
Agents | Barium sulfate | Potential Interferent | Concentration
----------------------------|--------------------------------------------|--------------------------|
| Miconazole
| 2% w/v |
| Hydrocortizone | 2% w/v |
| Zinc oxide | 40% w/v |
| Petroleum jelly | 100% |
| Phenylephrine
|
| Nonoxynol-9 | 7% |
| Benzalkonium
|
| Aluminum hydroxide,
|
| Ca carbonate | 0.5 mg/mL |
| Cimetidine | 0.5 mg/mL |
| Prilosec (delayed
|
| Mineral Oil | Mineral Oil | 2% v/v |
| Loperamide HCl | 0.00667 mg/mL |
| Bismuth Subsalicylate | 0.87 mg/mL |
| Sennosides | 0.1 mg/mL |
| Vancomycin HCl | Vancomycin | 12.5 mg/mL |
| Metronidazole | Metronidazole | 14 mg/mL |
Sodium
| 14 mg/mL |
| Whole blood | Glucose, hormones,
|
| Mucin | 3 mg/mL |
| Palmitic acid | 2 mg/mL |
| Stearic acid | 4 mg/mL |
| Barium sulfate | 5 mg/mL |

Table 7: Potentially Interfering Substances Tested

Represents physiologically relevant concentrations of substances

Performance Characteristics - Clinical Studies

The performance of the artus C. difficile QS-RGQ MDx Kit was evaluated at 3 external testing sites using C. difficile patient samples from 5 geographically diverse locations within the United States in 2013. The artus C. difficile QS-RGQ MDx Kit was compared to direct and/or enriched culture. The tables below present the data from these studies.

Assay vs. Direct and Enriched Culture Comparison

A total of 759 liquid or soft stool specimens were collected from patients suspected of having Clostridium difficile-associated disease. Ten (10) specimens were missing artus and culture results and were withdrawn from the study. Of the 749 specimens with artus results reported. sixteen (16) specimens reported an invalid result (2.14%) with the artus C. difficile QS-RGQ MDx Kit. Of these samples, 8 returned valid results upon retesting (all negative) and 8 reported a final invalid result for the artus C. difficile QS-RGQ MDx Kit (1.07%). The remaining 741 specimens with valid artus results were included in the final data set and analyzed for product performance.

Assav vs. Enriched Culture Comparison

A total of 741 specimens were tested by both the artus C. difficile QS-RGQ MDx Kit and enriched toxigenic culture. The overall assessment of sensitivity and specificity versus enriched toxigenic culture is shown in Table 8.

Table 8: Clinical Performance of artus C. difficile QS-RGQ MDx Kit vs. Enriched Toxigenic Culture

Combined Sites – Combined Ages
		Enriched Toxigenic Culture
		Positive	Negative	Total
artus C. difficile
QS-RGQ MDx
Kit	Positive	114	17*	131
	Negative	13**	597	610
	Total	127	614	741
			95% CI
Sensitivity		90%	83% - 94%
Specificity		97%	96% - 98%
Positive Predictive Value		87%	80% - 92%
Negative Predictive Value		98%	96% - 99%
Prevalence		17%	15%-20%

*17 discordant specimens (arus C. difficile QS-RGQ MDx Positive, Enriched Toxigenic Culture Negative) reported were analyzed by alternative PCR followed by bi-directional sequencing and the result was that 12 out of 17 were positive for toxigenic C. difficile, agreeing with the artus C. difficile QS-RGQ MDx result.

** 12 discordant specimens (artus C. difficile QS-RGO MDx Negative. Enriched Toxigenic Culture Positive) reported were analyzed by alternative PCR followed by bi-directional sequencing and the result was that 10 out of 12 were negative for toxigenic C. difficile, agreeing with the artus C. difficile QS-RGQ MDx result. The remaining I discordant specimen was unavailable for testing.

Assay vs. Direct Toxigenic Culture Comparison

There were a total of 699 specimens for which a direct toxigenic culture result was available. The overall assessment of sensitivity and specificity versus direct toxigenic culture is shown in Table 9.

Table 9: Clinical Performance of artus C. difficile QS-RGQ MDx Kit vs. Direct Toxigenic Culture

Combined Sites - Combined Ages
		Direct Toxigenic Culture
		Positive	Negative	Total
artus C. difficile
QS-RGQ MDx
Kit	Positive	84	21*	105
	Negative	1**	593	594
	Total	85	614	699
			95% CI
Sensitivity		99%	94%-100%
Specificity		97%	95%-98%
Positive Predictive Value		80%	71%-87%
Negative Predictive Value		100%	99%-100%
Prevalence		12%	10%-15%

*19 discordant specimens (artus C. difficile QS-RGQ MDx Positive. Direct Toxigenic Culture Negative) reported were analyzed by alternative PCR followed by bi-directional sequencing and the result was that 14 out of 19 were positive for toxigenic C. difficile, agrecing with the artus C. difficile QS-RGQ MDx result. The remaining 2 specimens were unavailable for testing.

** The I discordant specimen (artus C. difficile QS-RGQ MDx Negative, Direct Toxigenic Culture Positive) was unavailable for testing.

Conclusions

The artus® C. difficile QS-RGQ MDx Kit is substantially equivalent to the legally marketed Quidel Molecular Direct C. difficile Assay.

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QIAGEN GMBH KIMBERLY MAPP, Ph.D MANAGER, REGULATORY AFFAIRS 1201 CLOPPER ROAD GAITHERSBURG MD 20878

April 4, 2014

Re: K133936

Trade/Device Name: artus C. difficile QS-RGQ MDx Kit Regulation Number: 21 CFR 866.3130 Regulation Name: Clostridium difficile toxin gene amplification assay Regulatory Class: II Product Code: OZN, OOI Dated: January 6, 2014 Received: January 6, 2014

Dear Dr. Mapp:

、

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. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. 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); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

Page 2—Dr. Mapp

If you desire specific advice for your device on our labeling regulations (21 CFR Parts 801 and 809), please contact 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/MedicalDevices/ResourcesforYou/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR 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/MedicalDevices/ResourcesforYou/Industry/default.htm.

Sincerely yours,

Uwe Scherf -S 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

Indications for Use

510(k) Number (if known) K133936

Device Name artus® C. difficile QS-RGQ MDx Kit

Indications for Use (Describe)

The artus C. difficile QS-RGQ MDx Kit is an in vitro polymerase chain reaction (PCR) assay for use on the QIAsymphony RGQ MDx system for the qualitative detection of toxigenic Clostridium difficile toxin A and toxin B genes in human liquid or soft stool specients suspected of having Clostridium difficile associated disease. The test is intended to be used directly on patient samples.

The artus C. difficile QS-RGQ MDx Kit is intended to be used to aid in diagnosis of Clostridium difficile infection.

Type of Use (Select one or both, as applicable)

2 Prescription Use (Part 21 CFR 801 Subpart D)

Over-The-Counter Use (21 CFR 801 Subpart C)

Form Approved: OMB No. 0910-0120

Expiration Date: January 31, 2017

See PRA Statement below.

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FOR FOR FDA USE ONLY

Concurrence of Center for Devices and Radiological Health (CDRH) (Signature)

Ribhi Shawar -S 2014.04.01 07:31 22

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