The LightCycler® MRSA Advanced Test is a qualitative in vitro diagnostic test for the direct detection of nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) to aid in the prevention and control of MRSA infections in healthcare settings. The test is performed on the LightCycler® 2.0 Instrument with nasal swab specimens from patients suspected of colonization, uses swab extraction and mechanical lysis for specimen preparation followed by polymerase chain reaction (PCR) for the amplification of MRSA DNA, and fluorogenic target specific hybridization probes for the detection of the amplified DNA.

The LightCycler® MRSA Advanced Test is not intended to diagnose, guide or monitor treatment for MRSA infections. Concomitant cultures are necessary to recover organisms for epidemiology typing or for further susceptibility testing.

Device Description

The LightCycler® MRSA Advanced Test relies on 3 major processes: (1) specimen preparation by mechanical lysis of the bacterial cell walls, (2) PCR amplification of target DNA and detection by specific hybridization probes, and (3) automated result generation after melting peak analysis.

A nasal specimen is collected and transported to the laboratory in either BBL™ CultureSwab™ Liquid Stuart or Copan Venturi Transystem™ Liquid Stuart, BBL™ CultureSwab™ plus Amies gel with charcoal or Copan Venturi Transystem™ plus Amies gel with charcoal or BBL™ CultureSwab™ plus Amies gel without charcoal or Copan Venturi Transystem™ plus Amies gel without charcoal. Swab heads are cut into lysis tubes and subjected to heating to inactivate specimens. Subsequently lysis tubes are transferred in the MagNA Lyser Instrument where mechanical lysis of bacterial cell walls occurs, resulting in crude lysate preparations. After a brief centrifugation step to spin down glass beads and swab fibers, the processed specimen are subjected to PCR analysis using the LightCycler® MRSA Advanced Test.

The processed samples and the amplification mixture containing hot-start Tag polymerase are placed in LightCycler® Capillaries (20uL) in which PCR amplification will occur. Each LightCycler® MRSA Advanced Test reaction contains an internal control, which is designed to control for specimen inhibition, and to monitor reagent integrity. Also present in each LightCycler® MRSA Advanced Test is the AmpErase (uracil-N-glycosylase) enzyme. It recognizes and catalyzes the destruction of DNA strands containing deoxyuridine, but not DNA containing deoxythymidine. Since amplicons produced with the LightCycler® MRSA Advanced Test contain deoxyuridine, potential amplicon contaminants are eliminated during a prolonged heating step performed prior to the start of PCR amplification.

A target sequence in a plasmid is simultaneously amplified in the Positive Control. The Positive Control is intended to monitor for reagent failure and is included into each run. Each run also includes a Negative Control used to detect reagent or environmental contamination by MRSA DNA.

MRSA and Internal Control amplicons are detected by fluorescence using a specific pair of hybridization probes. The probes attach to a specific internal sequence in the amplified fragment and are positioned in a closed proximity to one another. Upon excitation, these bound probes emit a fluorescence signal of a specific wavelength using a process called Fluorescence Resonance Energy Transfer (FRET). The emitted light is measured by the Light ycler® 2.0 Instrument. MRSA or internal control specific amplicons are detected in parallel in two different detection channels and thus can be differentiated.

After completion of the real-time PCR process, a melting peak analysis is performed automatically by the LightCycler® 2.0 Instrument. Single stranded DNA amplicons with bound hybridization probes are subjected to increasing temperatures. When the PCR products reach a specific temperature one of the two bound hybridization probes melts off, resulting in a loss of fluorescence signal. The decrease in the fluorescence signal occurs at a specific temperature and results in melting peaks which are used to identify and distinguish MRSA- and Internal Controlspecific amplicons.

After a visual identification of the melting peaks is performed using Tm Bars in the LightCycler® Software, test results are transferred to a dedicated interpretation tool (the Micro Analysis Software) and a report is generated.

AI/ML Overview

Here's a summary of the acceptance criteria and study details for the LightCycler® MRSA Advanced Test, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance:

The document doesn't explicitly state 'acceptance criteria' in a formal table format with specific numerical targets before presenting the results. Instead, it presents the performance characteristics and implies that these results were deemed acceptable for substantial equivalence. The predicate device's performance is listed as a point of comparison (Sensitivity: 92.5%, Specificity: 96.4% using an enriched culture method).

Therefore, the table below reflects the reported performance of the LightCycler® MRSA Advanced Test in its clinical evaluation against the specified ground truths, which implicitly served as the demonstration of meeting the required performance for market clearance.

Performance Metric	Acceptance Criteria (Implied by Predicate/Demonstrated Performance)	Reported Device Performance (LightCycler® MRSA Advanced Test)	Ground Truth Used
Analytical Sensitivity (LoD)	Not explicitly stated (predicate not shown for this)	240 CFU/swab (95% confidence)	Quantified MRSA cultures
Analytical Inclusivity	High percentage of MRSA isolates detected	99.3% (136/137) of NARSA strains detected; 95% (1561/1643) of additional isolates	Well-characterized MRSA isolates (NARSA Program, clinical sites)
Analytical Specificity (Exclusivity)	High percentage of non-MRSA organisms showing no cross-reactivity	98.9% of tested organisms showed no cross-reactivity	Identified bacterial, viral, fungal species, human DNA
PPA vs. Direct Chromogenic Culture	Comparable to predicate (92.5%)*	95.2% (91.1%, 97.8% CI)	Direct Chromogenic Culture
NPA vs. Direct Chromogenic Culture	Comparable to predicate (96.4%)*	96.4% (95.2%, 97.4% CI)	Direct Chromogenic Culture
PPA vs. Second FDA-Cleared NAAT	Not explicitly stated (used as comparison, not a target)	71.7% (65.9%, 77.0% CI)	Second FDA-Cleared NAAT
NPA vs. Second FDA-Cleared NAAT	Not explicitly stated (used as comparison, not a target)	98.2% (97.2%, 98.9% CI)	Second FDA-Cleared NAAT
PPA vs. Broth Culture	Not explicitly stated (broth is more sensitive benchmark)	89.8% (84.8%, 93.5% CI)	Broth Culture
NPA vs. Broth Culture	Not explicitly stated (broth is more sensitive benchmark)	96.8% (95.6%, 97.7% CI)	Broth Culture
Reproducibility	High agreement across lots, sites, days	Negative: 98-100%; Below LoD: 41-58%; Weak Positive: 99-100%; Positive: 98-100%	Spiked samples with known concentrations

*Note on Predicate Comparison: The predicate device's performance was reported using an enriched culture method as its ground truth, while the LightCycler® MRSA Advanced Test was initially compared to direct chromogenic culture. Discrepancy analysis also suggested the LightCycler® test might be more sensitive than direct chromogenic culture alone. The "substantial equivalence" claim hinges on the overall body of evidence.

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

Clinical Performance (Method Comparison):
- Initial samples collected: 1,620 nasal swab specimens.
- Eligible for statistical analysis: 1,402 specimens.
- Data Provenance: Multi-site prospective investigational study at 5 institutions across the United States.
Analytical Inclusivity (Epidemiological Clones):
- NARSA strains: 137 isolates.
- Additional isolates: 1,643 isolates (65% Europe, 35% U.S.).
- Data Provenance: NARSA Program (NIAID/NIH contract) and clinical sites in the U.S. and Europe.
Analytical Specificity (Exclusivity):
- Cross-reactivity panel: 13 viral, 66 bacterial, 7 fungal species, human DNA (total 87 distinct species/DNA).
- Additional strains: 117 methicillin-resistant coagulase-negative staphylococci, 104 methicillin-sensitive coagulase-negative staphylococci, 100 methicillin-sensitive Staphylococcus aureus.
- Data Provenance: Not explicitly stated, but likely laboratory-sourced or reference strains from various locations.

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

The ground truth for the clinical performance study was established by culture methods (direct chromogenic culture and broth culture), not by human experts interpreting results. The text does not mention any experts for establishing ground truth for the primary clinical study endpoint.

However, for the discrepancy analysis, further investigation was performed, including "testing for mecA mediated Oxacillin resistance using cefoxitin disk diffusion methodology, fem- and mecA-specific PCR, and sequencing of SCCmec regions." This implies expert laboratory analysis to confirm the presence or absence of MRSA, but the number and specific qualifications of those experts are not provided.

4. Adjudication Method for the Test Set:

For the clinical performance study, the primary ground truth was established by culture methods (direct chromogenic culture and broth culture). The results were compared against these predefined culture outcomes.

No explicit "adjudication method" involving multiple human readers/experts is described for the primary comparison.
Discrepancy Analysis: When discordance occurred between the LightCycler® MRSA Advanced Test and the culture ground truth (or between the LightCycler test and the second FDA-cleared NAAT), further confirmatory molecular testing was used to resolve these discrepant results. This served as a form of "adjudication" based on advanced laboratory techniques.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done, What Was the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance:

No. This device is a fully automated in-vitro diagnostic test (nucleic acid amplification test) for direct detection of MRSA. It does not involve human readers interpreting images or data where AI assistance would be applicable in the sense of improving human reader performance. Therefore, an MRMC comparative effectiveness study of this nature was not conducted.

6. If a Standalone (i.e. algorithm only, without human-in-the-loop performance) Was Done:

Yes, the entire clinical performance study and analytical studies represent a standalone performance evaluation of the LightCycler® MRSA Advanced Test. The device provides "automated result generation after melting peak analysis" (page 4), and results are transferred to a "dedicated interpretation tool (the Micro Analysis Software)" to generate a report (page 4). The performance metrics provided (PPA, NPA, sensitivity, specificity, inclusivity, exclusivity) are a direct measure of the device's accuracy without human interpretation influencing the final call. The human interaction is limited to specimen preparation and loading, and the machine-generated result is the standalone output.

7. The Type of Ground Truth Used (Expert Consensus, Pathology, Outcomes Data, etc.):

Clinical Performance (Method Comparison):
- Direct Chromogenic Culture: Used as a primary comparator.
- Broth Culture: Used as a more sensitive comparator.
- Discrepancy Analysis: Advanced molecular testing (mecA mediated Oxacillin resistance, fem- and mecA-specific PCR, SCCmec region sequencing) was used to confirm MRSA presence in discrepant samples. This represents a more definitive, complex laboratory-based ground truth.
Analytical Sensitivity (LoD): Quantified MRSA cultures.
Analytical Inclusivity: Well-characterized MRSA isolates (epidemiological clones).
Analytical Specificity (Exclusivity): Identified bacterial, viral, fungal species, and human DNA.
Reproducibility: Spiked samples with known concentrations of MRSA and MSSE.

8. The Sample Size for the Training Set:

The document does not explicitly describe a separate "training set" in the context of machine learning or AI algorithm development. This device is a molecular diagnostic test governed by predefined PCR assays and melting curve analysis, not a learning algorithm that requires a separate training phase. The analytical and clinical studies described evaluate the performance of the fully developed test.

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

As there is no described training set for an AI/machine learning algorithm, this question is not applicable to the information provided. The ground truths for the various analytical and clinical studies (LoD, inclusivity, exclusivity, clinical comparison) were established as described in point #7.

Summary

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1091409

510(k) Summary

JUL -- 6 2010

Submitted by:	Roche Molecular Systems, Inc.4300 Hacienda DrivePleasanton, CA 94588-2722
	Phone Number: (925) 730-8040Fax Number: (925) 730-8128
Contact:	Larry Pietrelli
Date of Preparation:	July 1, 2010
Device Trade Name:	LightCycler® MRSA Advanced Test
Common Name:	Methicillin-resistant Staphylococcus aureus (MRSA) Test
Type of Test:	Nucleic Acid Amplification Test, DNA, Methicillin-resistantStaphylococcus aureus (MRSA), qualitative
Classification Name:	Antimicrobial susceptibility powder
Regulation:	866.1640
Procode:	NQX,OOI Nuclei Acid Amplification System, Real Time
Classification Advisory:	Microbiology
Committee:
Predicate Device:	BD GeneOhm™ MRSA Assay(510(k) numbers K033415/K042357)

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		Table of Contents
1.	Device Description
2.	Intended Use………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
3.	Substantial Equivalence
4.	Non-Clinical Performance Evaluation
	4.1.	Analytical Sensitivity
	4.2.	Inclusivity
	4.3.	Analytical Specificity
		Exclusivity4.3.1.
5.	Clinical Performance
	5.1.	Method Comparison
	5.2.	Reproducibility
6.	Conclusion

List of Tables

Table 1: Substantial Equivalence between LightCycler MRSA Advanced Test and Predicate
Device
Table 2: Detection of MRSA in various transport media
Table 3: MRSA Isolates Representative of Epidemiological Clones Obtained from the Network
on Antimicrobial Resistance in Staphylococcus aureus (NARSA) Program and well
Characterized Isolates from Clinical Sites
Table 4: Species Tested for Cross Reactivity with the LightCycler® MRSA Advanced Test 9
Table 5: Comparison of the LightCycler® MRSA Advanced Test With
Table 6: Comparison of the LightCycler® MRSA Advanced Test with the Second FDA-Cleared
NAAT

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Table 7: Comparison of the LightCycler® MRSA Advanced Test with	16
Table 8: Summary of Reproducibility Results	18

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DEVICE DESCRIPTION 1.

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2. INTENDED USE

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SUBSTANTIAL EQUIVALENCE 3.

As indicated in Table 1, the RMS LightCycler® MRSA Advanced Test is substantially equivalent to those characteristics for the predicate device (BD GeneOhm MRSA assay). Both assays have the same intended use, and utilize PCR technology for amplification and detection of MRSA from nasal swabs.

Data as presented in this pre-market notification further support the substantial equivalence.

	LightCycler MRSAAdvanced Test	Predicate Device:BD GeneOhm MRSA
Intended Use	Qualitative in vitro diagnostic testfor the direct detection of nasalcolonization with Methicillin-resistant Staphylococcus aureus(MRSA) to aid in the preventionand control of MRSA infections inhealthcare settings	same
Sample Type	Nasal swab	same
Sample Collection / Transport /Storage	Liquid Stuart swabs,22 to 25°C for 6 days,2 to 6°C for 5 days, and1 month at -25 to -15°C.Amies Gel with charcoal swabs,Amies Gel without charcoal swabs22 - 25°C for 4 days	Liquid Stuart swabs,15- 30°C for 36 hours,2-8°C for up to 5 days
Time to Result	2 hours (16 samples, wholeworkflow)	60 - 75 minutes (depending onnumber of samples)
Workflow	multiple manual steps includingpipetting, fluid transfer, vortexing,centrifugation and sample heating	same
Lysis	mechanical lysis using glass beads	same
Assay Platform	LightCycler	SmartCycler
Mode of Detection	Nucleic acid amplification (DNA)utilizing real-time PCR	same
DNA Target Sequence	sequence incorporating theinsertion site of the SCCmec in theS. aureus orfx gene	similar but not identical sequence

Table 1: Substantial Equivalence between LightCycler MRSA Advanced Test and Predicate Device

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	LightCycler MRSAAdvanced Test	Predicate Device:BD GeneOhm MRSA
Detection Chemistry	paired target-specific hybridizationprobes using fluorescenceresonance energy transfer (FRET)	target-specific hybridization probes(molecular beacon technology)
Result Analysis	based on melting peak analysis	based on analysis of amplificationcurves
Internal Assay Controls	internal assay control to detectinhibitory specimens and to confirmintegrity of reagent in negativesamples	same
External Assay Controls	provided: positive control tomonitor for reagent integrity	same
External Controls for WholeWorkflow	available but not provided(commercial productrecommended in PI)	available but not provided(commercial productrecommended in PI)
Comparison Performancecharacteristics	Direct chromogenic culture methodPositive agreement: 95.2%Negative agreement: 96.4%	Sensitivity: 92.5%Specificity: 96.4%*BD GeneOhm™ MRSA PackageInsert using an enriched culturemethod

4. NON-CLINICAL PERFORMANCE EVALUATION

4.1. Analytical Sensitivity

The analytical sensitivity of the LightCycler® MRSA Advanced Test was determined using 3 strains of MRSA representing the three RE types targeted with this assay (right extremity of the SCCmec/orfX junction (RE) types 2, 3, and 7). Cultures of these strains were quantified, diluted to values spanning the range of 100 to 400 colony forming units (CFU) per swab, and absorbed onto swabs previously soaked into various transport media. All dilutions around the LOD value were tested in replicates of at least 30. Limit of detection obtained for each strain type and swab type tested represents the lowest number of CFU/swab at which a positive result will be obtained with at least 95% confidence. Results indicate that the LightCycler® MRSA Advanced Test will produce a positive results with 95% confidence for a swab containing 240 CFU.

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Swab Types	CFU/swab
Liquid Stuart transport media	240
Amies gel without charcoal transport media	240
Amies gel with charcoal transport media	240

Table 2: Detection of MRSA in various transport media

4.2. Inclusivity

Performance of the LightCycler® MRSA Advanced Test for 137 well characterized MRSA isolates representative of epidemiologic clones in the U.S. is shown in Table 3. The strains were obtained through the Network on Antimicrobial Resistance in Staphylococcus aureus (NARSA) Program supported under NIAID/NIH Contract No. HHSN272200700055C and from clinical sites. All strains were tested as cultures at a concentration of 10E5 cfu/mL.

All but 1 isolate tested positive with the LightCycler® MRSA Advanced Test (99.3%).

Table 3: MRSA Isolates Representative of Epidemiological Clones Obtained from the Network on Antimicrobial Resistance in Staphylococcus aureus (NARSA) Program and well Characterized Isolates from Clinical Sites

USA type	Number ofisolatestested	Isolates withpositive resultsby theLightCycler®MRSA AdvancedTest
100	54*	53
200	5	5
300	37	37
400	4	4
500	7	7
600	3	3
700	4	4
800	7	7
1000	7	7
1100	4	4
Nottypable/	5	5

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unknown
Total	137	136 (99.3%)

*Of the 54 type USA 100 strains tested, one strain (NRS642) was negative by the LightCycler® MRSA Advanced Test

An additional 1,643 isolates other than those listed in Table 3 were collected in Europe (65%) and in the U.S. (35%) and tested by the LightCycler® MRSA Advanced Test. Of the 1,643 isolates tested, 1,561 (95%) were correctly identified as MRSA while 82 were negative by the LightCycler® MRSA Advanced Test.

Analytical Specificity 4.3.

4.3.1. Exclusivity

The specificity of the LightCycler® MRSA Advanced Test was evaluated by testing for cross reactivity to pathogenic microorganisms and to contaminants potentially present in normal nasal microflora. Tested species consisted of 13 viral, 66 bacterial and 7 fungal species as outlined in Table 4. The microorganisms were tested either as cultures in concentrations of 10E6 to 10E7 cfu/mL or as genomic DNA preparations in concentrations of 10 pg/PCR. In addition human DNA in a concentration of 5 ng/reaction was tested. Human DNA and all tested species except for one, were found negative for MRSA with the LightCycler® MRSA Advanced Test.

Table 4: Species Tested for Cross Reactivity with the LightCycler® MRSA Advanced Test
Species
Staphylococcus aureus (MSSA)	Haemophilus influenzae
Staphylococcus cohnii ssp. cohnii	Haemophilus parainfluenzae
Staphylococcus epidermidis	Herpes simplex virus 1
Staphylococcus haemolyticus	Human DNA
Staphylococcus hominis	Influenza A (H1N1), A (H3N2)
Staphylococcus intermedius	Influenza B
Staphylococcus lugdunensis	Issatchenkia orientalis (Candida krusei)
Staphylococcus pseudointermedius	Klebsiella pneumoniae ssp. ozeanae
Staphylococcus saprophyticus	Kocuria kristinae
Staphylococcus schleiferi ssp. coagulans	Kytococcus schroeteri
Staphylococcus sciuri	Lactobacillus delbrueckii ssp. delbrueckii
Staphylococcus simulans	Legionella pneumophila
Staphylococcus warneri	Metapneumovirus
Staphylococcus xylosus	Microbacterium testaceum
Acinetobacter baumannii	Micrococcus luteus

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Actinobacillus actinomycetemcomitans	Moraxella catarrhalis
Actinomyces odontolyticus	Morganella morganii
Adenovirus 7A	Mycobacterium avium
Aerococcus urinaeequi	Mycoplasma pneumoniae
Aspergillus fumigatus	Mycoplasma salivarium
Bacteroides fragilis	Neisseria meningitidis
Bacteroides uniformis	Oerskovia jenensis
Bacteroides vulgatus	Parainfluenza 1
Bordetella bronchioseptica	Parainfluenza 2
Bordetella parapertussis	Parainfluenza 3
Bordetella pertussis	Parvimonas micra (Peptostreptococcus micros)
Burkholderia cepacia	Peptostreptococcus stomatis
Candida albicans	Peptostreptococcus anaerobius
Candida glabrata	Planococcus maritimus
Candida parapsilosis	Proteus mirabilis
Candida tropicalis	Proteus vulgaris
Citrobacter freundii	Pseudomonas putida
Coronavirus	Pseudomonas aeruginosa
Corynebacterium glutamicum	Respiratory syncytial virus (RSV A, B & A2)
Corynebacterium amycolatum	Rhinovirus
Corynebacterium jeikeium	Rhodococcus equi
Cryptococcus neoformans	Rothia mucilaginosa*
Eikenella corrodens	SARS
Enterococcus faecalis	Streptococcus agalactiae
Enterococcus faecium	Streptococcus pneumoniae
Enterovirus	Streptococcus pyogenes
Escherichia coli	Streptococcus viridans
Finegoldia magna (Peptostreptococcus magnus)	Veillonella atypica
Haemophilus aphrophilus

Initial test results were weakly positive. Retested eight times and all tests were negative for MRSA DNA.

An absence of cross-reactivity was observed for 98.9% of the organisms tested

In addition, 117 isolates of methicillin-resistant coagulase negative staphylococci, 104 isolates of methicillin-sensitive coagulase negative staphylococci and 100 isolates of methicillin-sensitive Staphylococcus aureus obtained from different European clinical centers were tested at

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concentrations of 10E4 to 10E5 cfu/reaction. All additional strains tested negative with the LightCycler® MRSA Advanced Test.

5. CLINICAL PERFORMANCE

5.1. Method Comparison

Performance characteristics of the LightCycler® MRSA Advanced Test were determined in a multi-site prospective investigational study at 5 institutions by comparing the LightCycler® MRSA Advanced Test with a second FDA-cleared nucleic acid amplification test (NAAT), direct chromogenic culture, and broth culture (the more sensitive culture method). Subjects included individuals and medical staff at risk for nasal colonization. Each subject was enrolled in the study only one time. Subjects who had received systemic or topical-nasal antibiotics used to treat nasal colonization with MRSA from the day of sample collection and up to one week prior to study enrollment, under 2 years of age, and/or had contraindication to nasal swab collection were excluded from the study. Only those subjects meeting the inclusion and exclusion criteria were enrolled.

A double-headed nasal swab was collected from each subject. One swab head was directly streaked onto a quadrant of a chromogenic agar plate with cefoxitin, and then processed according to the package insert for testing with the LightCycler® MRSA Advanced Test. The remaining quadrants of the chromogenic agar were streaked using a sterile loop. The second swab head was directly streaked onto a separate chromogenic plate with cefoxitin, and then processed for testing with the second FDA-cleared NAAT test (according to the package insert). Thereafter, the second swab head was transferred into Trypticase Soy Broth and incubated for 48 hours at 35-37°C and then subcultured onto a chromogenic plate with cefoxitin. Chromogenic culture plates were incubated at 35-37℃ for 20-48 hours. Presumptive MRSA colonies from all culture plates were confirmed by coagulase testing and Gram staining if found after 44-48 hours of incubation. Each participating site performed all tests.

Performance of the LightCycler® MRSA Advanced Test and the second FDA-cleared NAAT test were calculated relative to the direct chromogenic culture, and the broth culture results. Samples

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that grew MRSA on direct chromogenic culture from either swab head A and/or swab head B were considered MRSA positive unless otherwise stated.

A total of 1,620 nasal swab specimens were collected from subjects at 5 sites across the United States and tested with the LightCycler® MRSA Advanced Test. Of the 1,620 specimen tested, 1.402 specimens were eligible to be included in statistical analyses' The overall number of positive MRSA samples by direct chromogenic culture was 187 (13.3%).

Results obtained in nasal swabs from eligible subjects tested for MRSA using the LightCycler® MRSA Advanced Test compared to direct chromogenic culture, the 2nd FDA-cleared NAAT, and broth culture are shown in Tables 5, 6, and 7, respectively. Included in Table 5 are 1,402 evaluable specimens that had valid LightCycler® MRSA Advanced Test and direct chromogenic culture results. Included in Table 6 are 1,385 specimens with valid results for the LightCycler® MRSA Advanced Test and the second FDA-cleared NAAT test who additionally had concordant direct chromogenic culture results from swab heads A and B. Included in Table 7 are 1,395 evaluable specimens that had valid LightCycler® MRSA Advanced Test and broth culture results.

1 218 specimens were not evaluable for statistical analyses: 36 subjects did not meet study inclusion / exclusion criteria. 153 specimens were not tested according to the study protocol. 22 specimens were invalid due to external control failure, and 7 specimens were invalid due to internal control failures. Upon retest these 7 specimens remained invalid due to internal control failure.

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Table 5: Comparison of the LightCycler® MRSA Advanced Test With

	Direct chromogenic culture
LightCycler® MRSAAdvanced Test	Positive	Negative	Total
Positive	178	44	222
Negative	9	1,171	1,180
Total	187	1,215	1,402
Positive PercentAgreement(95% exact CIᵃ)	95.2%(91.1%,97.8%)
Negative PercentAgreement(95% exact CIᵃ)		96.4%(95.2%,97.4%)

Direct Chromogenic Culture

Note: Included in this summary table are 1,402 evaluable specimens that had valid LightCycler® MRSA Advanced Test and direct chromogenic culture results.

4 CI = confidence interval

Of the 178 samples with positive results for the LightCycler® MRSA Advanced Test and direct chromogenic culture, the second FDA-cleared NAAT was positive for 175 samples and negative for 3 samples.

For the 44 samples that were positive for the LightCycler® MRSA Advanced Test and negative for direct chromogenic culture, the second FDA-cleared NAAT was positive for 25 samples and negative for 19 samples.

For the 9 samples that were negative for the LightCycler® MRSA Advanced Test and positive for direct chromogenic culture, the second FDA-cleared NAAT was positive for 4 samples and negative for 5 samples.

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Of the 1,171 samples with negative results for the LightCycler® MRSA Advanced Test and direct chromogenic culture, the second FDA-cleared NAAT was positive for 76 samples, negative for 1,091 samples, and missing/invalid for 4 samples.

Discrepancy Analysis:

Further investigation (i.e., testing for mecA mediated Oxacillin resistance using cefoxitin disk diffusion methodology, fem- and mecA-specific PCR, and sequencing of SCCmec regions) was performed on all samples that gave discordant results between direct chromogenic culture (samples that gave concordant results in swab heads A and B only) and the LightCycler" MRSA Advanced Test LightCycler® MRSA Advanced Test or between direct chromogenic culture (samples that gave concordant results in swab A and B only) and the second FDA-cleared NAAT.

. Discrepancy analysis confirmed the presence of MRSA in 30 of 44 samples in which the LightCycler® MRSA Advanced Test gave a positive result but direct chromogenic culture was negative.
The presence of MRSA was confirmed in 4 of 9 samples in which the LightCycler® . MRSA Advanced Test gave a negative result but direct chromogenic culture was positive.
The presence of MRSA was confirmed in 13 of 76 samples in which the second FDA-. cleared NAAT gave a positive result but the LightCycler® MRSA Advanced Test and the direct chromogenic culture gave a negative result.

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	The Second FDA-Cleared NAAT
LightCycler® MRSA AdvancedTest	Positive	Negative	Total
Positive	195	20	215
Negative	77	1,093	1,170
Total	272	1,113	1,385
Positive Percent Agreement(95% exact CIa)	71.7%(65.9%,77.0%)
Negative Percent Agreement(95% exact CIa)		98.2%(97.2%,98.9%)

Table 6: Comparison of the LightCycler® MRSA Advanced Test with the Second FDA-Cleared NAAT

Note: Included in this summary are 1,385 specimens with valid results for the LightCycler® MRSA Advanced Test and the second FDAcleared NAAT test who additionally had concordant direct chromogenic culture results from swab heads A and B

ªCI = confidence interval.

Of the 195 samples with positive results for the LightCycler® MRSA Advanced Test and the second FDA-cleared NAAT, direct chromogenic culture was positive for 171 samples and negative for 24 samples (MRSA was confirmed in 20 of these 24 samples from discrepancy analysis).

For the 20 samples that were positive for the LightCycler® MRSA Advanced Test and negative for the second FDA-cleared NAAT, direct chromogenic culture was positive for 1 sample and negative for 19 samples (MRSA was confirmed in 10 of these 19 samples from discrepancy analysis).

For the 77 samples that were negative for the LightCycler® MRSA Advanced Test and positive for the second FDA-cleared NAAT, direct chromogenic culture was positive for 1 sample and negative for 76 samples (MRSA was confirmed in 13 of these 76 samples from discrepancy analysis).

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Of the 1,093 samples with negative results for the LightCycler® MRSA Advanced Test and the second FDA-cleared NAAT, direct chromogenic culture was positive for 4 samples (MRSA was confirmed in all 4 samples from discrepancy analysis) and negative for 1,089 samples.

	Broth Culture
LightCycler® MRSAAdvanced Test	Positive	Negative	Total
Positive	184	38	222
Negative	21	1,152	1,173
Total	205	1,190	1,395
Positive PercentAgreement(95% exact CIª)	89.8%(84.8%,93.5%)
Negative PercentAgreement(95% exact CIª)		96.8%(95.6%,97.7%)
Note: A total of 1,395/1,402 evaluable specimens that had validLightCycler® MRSA Advanced Test and broth culture results areincluded in this summary table. Broth culture results weremissing/invalid for 7/1,402 evaluable specimens.ªCI = confidence interval.

Table 7: Comparison of the LightCycler® MRSA Advanced Test with Broth Culture

5.2. Reproducibility

A panel of specimens with varying concentrations of MRSA and methicillin-sensitive Staphylococcus epidermidis (MSSE) were tested. Two operators at each of 3 sites performed one run each per day for 5 days on three reagent lots (4 specimens x 3 replicates x 5 days x 3 lots x 2 operators). A 12-member panel was used that was composed of specimens of Methicillin-resistant Staphylococcus aureus (MRSA) strain ATCC 43300 diluted to the concentrations shown in Table 8. Methicillin-sensitive Staphylococcus epidermidis (MSSE) ATCC strain 14990 was included in each panel member at a constant level to achieve an

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appropriate sample matrix. The panel included negative member, below the LOD (20 CFU/swab expected to yield a positivity rate of between 30 to 70%), weak positive (300 CFU/swab), and positive (800 CFU/swab). The negative panel member yield negative results from a low of 99% to 100% , the below LOD panel member positivity rate range from a low of 42% to 47%, the weak positive panel member positivity rate range from a low of 99% to 100%, and the positive panel member positivity rate range from a low of 99% to 100% depending on the site.

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MRSACFU/swab	SampleType	TmMean(°C)	TmStandardDeviation	TmCV(%)	Lot to Lot			Site to Site			Day to Day
					Lot	No./No.Tested	%	Site	No./No.Tested	%	Day	No./No.Tested	%
0	Negative	n/a	n/a	n/a	1	90/90	100%	1	90/90	100%	1	53/54**	98%
					2	90/90	100%	2	89/90**	99%	2	54/54	100%
					3	89/90**	99%	3	90/90	100%	3	54/54	100%
											4	54/54	100%
											5	54/54	100%
20*	Below LOD	59.56	0.22	0.4	1	52/90	58%	1	38/90	42%	1	25/54	46%
					2	30/90	33%	2	41/90	46%	2	26/54	48%
					3	39/90	43%	3	42/90	47%	3	22/54	41%
											4	25/54	46%
											5	23/54	43%
300	WeakPositive	59.48	0.20	0.3	1	90/90	100%	1	89/90	99%	1	53/54	98%
					2	89/90	99%	2	90/90	100%	2	54/54	100%
					3	90/90	100%	3	90/90	100%	3	54/54	100%
											4	54/54	100%
											5	54/54	100%
800	Positive	59.43	0.21	0.3	1	90/90	100%	1	90/90	100%	1	53/54**	98%
					2	90/90	100%	2	89/90**	99%	2	54/54	100%
					3	89/90**	99%	3	90/90	100%	3	54/54	100%
											4	54/54	100%
											5	54/54	100%

	Table 8: Summary of Reproducibility Results

Note: *Concentration that produces approximately 30%–70% positive results.

**There was an apparent transposition of one positive and one negative sample positioned adjacent to each other in the same run. Excluding these samples from the analysis results for lot to lot, site to site, and day to day reproducibility would be 100%.

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6. CONCLUSION

The results of the non-clinical analytical and clinical performance studies summarized above demonstrate that the device is as safe and as effective as the predicate device.

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Image /page/19/Picture/1 description: The image shows the logo for the Department of Health & Human Services - USA. The logo features a stylized eagle with three curved lines representing its body and wings. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" is arranged in a circular pattern around the eagle.

Food and Drug Administration 10903 New Hampshire Avenue Document Mail Center - WO66-0609 Silver Spring, MD 20993-0002

Larry Pietrelli Director, Regulatory Affairs Roche Molecular Systems, Inc. 4300 Hacienda Drive Pleasanton, California 94588-2722

JUL 0 6 2010

Re: K091409

Trade/Device Name: LightCycler® MRSA Advanced Test Regulation Number: 21 CFR §866.1640 Regulation Name: Antimicrobial susceptibility test powder Regulatory Class: Class II Product Code: NQX,00I Dated: June 11, 2010 June 14, 2010 Received:

Dear Mr. Pietrelli:

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 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 Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set

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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.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please go to http://www.fda.gov/AboutFDA/CentersOffices/CDRH0ffices/ucm115809.htm for the Center for Devices and Radiological Health's (CDRH's) Office of Compliance. 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/Resourcesfor You/Industry/default.htm.

Sincerely yours,

Sally Arthur

Sally A. Hojvat, M.Sc. Director Division of Microbiology Devices Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known): K091409

Device Name: LightCycler® MRSA Advanced Test

Indications for Use:

Prescription Use X Part 21 CRF 801 Subpart D) Over-the Counter Use (21 CRF 801 Subpart C)

PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE

AND/OR

Concurrence of CDRH, Office of Hr. Vitro Diagnostic Devices (OIVD)

Tall a
Division Sign-Off

Office of In Vitro Diagnos Device Evaluation and S

510(k) K091409

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

510(k)

Regulation Number and Section

§ 866.1640 Antimicrobial susceptibility test powder.

(a)
Identification. An antimicrobial susceptibility test powder is a device that consists of an antimicrobial drug powder packaged in vials in specified amounts and intended for use in clinical laboratories for determining in vitro susceptibility of bacterial pathogens to these therapeutic agents. Test results are used to determine the antimicrobial agent of choice in the treatment of bacterial diseases.(b)
Classification. Class II (performance standards).