EK/P. AERUGINOSA PNA FISH

K081433 · Advandx, Inc. · JSS · Mar 26, 2009 · Microbiology

Device Facts

• Record ID: K081433
• Device Name: EK/P. AERUGINOSA PNA FISH
• Applicant: Advandx, Inc.
• Product Code: JSS · Microbiology
• Decision Date: Mar 26, 2009
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.2660
• Device Class: Class 1

Indications for Use

EK/P. aeruginosa PNA FISH is a multicolor, qualitative nucleic acid hybridization assay intended for identification of Escherichia coli /Klebsiella pneumoniae and Pseudomonas aeruginosa on smears from positive blood cultures containing Gram-negative rods. The test does not distinguish between E. coli and K. pneumoniae. Further testing is needed to differentiate E. coli and K. pneumoniae. The EK/P. aeruginosa PNA FISH assay is indicated for use in conjunction with positive blood subcultures as an aid in the identification of E. coli/Klebsiella pneumoniae, and/or P. aeruginosa.

Device Story

EK/P. aeruginosa PNA FISH is a qualitative nucleic acid hybridization assay; utilizes Peptide Nucleic Acid (PNA) probes for identification of specific bacterial species. Input: smears from positive blood cultures containing Gram-negative rods. Process: hybridization of fluorescently labeled PNA probes to target ribosomal RNA sequences within bacterial cells; visualization via fluorescence microscopy. Output: qualitative identification of E. coli/K. pneumoniae and/or P. aeruginosa. Used in clinical microbiology laboratories by trained laboratory personnel. Results provide rapid identification to assist clinicians in selecting appropriate antimicrobial therapy, potentially improving patient outcomes by enabling targeted treatment earlier than traditional culture-based methods.

Clinical Evidence

No clinical data provided in the summary document. Substantial equivalence is based on analytical performance characteristics and technological comparison to the predicate device.

Technological Characteristics

Qualitative nucleic acid hybridization assay using PNA probes. Employs fluorescence microscopy for detection. Form factor: kit containing reagents and PNA probes. No software algorithm or electronic connectivity; manual interpretation of fluorescent signals.

Indications for Use

Indicated for identification of E. coli/K. pneumoniae and P. aeruginosa in patients with positive blood cultures containing Gram-negative rods. Prescription use only.

Regulatory Classification

Identification

A microorganism differentiation and identification device is a device intended for medical purposes that consists of one or more components, such as differential culture media, biochemical reagents, and paper discs or paper strips impregnated with test reagents, that are usually contained in individual compartments and used to differentiate and identify selected microorganisms. The device aids in the diagnosis of disease.

Predicate Devices

• E. faecalis/OE PNA FISH (K063127)

Submission Summary (Full Text)

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510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION
DECISION SUMMARY
ASSAY ONLY TEMPLATE

A. 510(k) Number:
K081433

B. Purpose for Submission:
Request substantial equivalence for a new device

C. Measurand:
E. coli + Klebsiella pneumoniae and P. aeruginosa specific ribosomal RNA sequences

D. Type of Test:
Fluorescence In Situ Hybridization (FISH) using protein nucleic acid (PNA) probes

E. Applicant:
AdvanDx, Inc

F. Proprietary and Established Names:
EK/P. aeruginosa PNA FISH™

G. Regulatory Information:
1. Regulation section:
866.2660
2. Classification:
Class I
3. Product code:
JSS
4. Panel:

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83 Microbiology

H. Intended Use:

1. Intended use(s):

EK/P. aeruginosa PNA FISH is a multicolor, qualitative nucleic acid hybridization assay intended for identification of Escherichia coli /Klebsiella pneumoniae and Pseudomonas aeruginosa on smears from positive blood cultures containing Gram-negative rods. The test does not distinguish between E. coli and K. pneumoniae. Further testing is needed to differentiate E. coli and K. pneumoniae. The EK/P. aeruginosa PNA FISH assay is indicated for use in conjunction with positive blood subcultures as an aid in the identification of E. coli/Klebsiella pneumoniae, and/or P. aeruginosa.

2. Indication(s) for use:

EK/P. aeruginosa PNA FISH is a multicolor, qualitative nucleic acid hybridization assay intended for identification of Escherichia coli /Klebsiella pneumoniae and Pseudomonas aeruginosa on smears from positive blood cultures containing Gram-negative rods. The test does not distinguish between E. coli and K. pneumoniae. Further testing is needed to differentiate E. coli and K. pneumoniae. The EK/P. aeruginosa PNA FISH assay is indicated for use in conjunction with positive blood subcultures as an aid in the identification of E. coli/Klebsiella pneumoniae, and/or P. aeruginosa.

3. Special conditions for use statement(s):

Prescription use only

4. Special instrument requirements:

Fluorescence microscope with Dual Band Filter (Cat. No. AC003) and Microscope Slides (Cat. No. AC001)

I. Device Description:

A mixture of fluorescein-labeled, E. coli, a fluorescein-labeled K. pneumoniae specific PNA probe and a Texas Red labeled, P. aeruginosa specific PNA probe is added to a smear prepared from a positive blood culture. Hybridization is performed at 55°C for 90 min. The hybridization is followed by a water rinse at 55°C to remove the cover slips followed by a wash at 55°C for 30 min. with a stringent wash solution. The smear is finally mounted with Mounting Medium for examination with fluorescence microscopy (Dual Band Filter). E. coli and K. pneumoniae are bright green fluorescent rods whereas P. aeruginosa are bright red fluorescent rods.

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The test does not distinguish between $E$ coli and $K$ pneumoniae.

# J. Substantial Equivalence Information:

1. Predicate device name(s):

E. faecalis/OE PNA FISH

2. Predicate 510(k) number(s):

K063127

3. Comparison with predicate:

| Similarities | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Technology | Fluorescence In Situ Hybridization (FISH) using protein nucleic acid (PNA) probe | Same |
| Sample | Positive blood culture | Same |
| Interpretation of Results | Qualitative Fluorescence microscope | Same |
| | | |
| Differences | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Function | Identification of Escherichia coli/K. pneumoniae and Pseudomonas aeruginosa | Identification of E. faecalis and other Enterococci |
| Control organisms | Pos control: E. coli ATCC 35218 and P. aeruginosa ATCC 10145 Neg control: Klebsiella oxytoca ATCC 43086 | Pos control: E. faecalis and E. faecium Neg control: Streptococcus spp |
| PNA Probes | E. coli + P. aeruginosa and P. aeruginosa | E. faecalis and other Enterococci |

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K. Standard/Guidance Document Referenced (if applicable):

Non applicable

L. Test Principle:

A mixture of fluorescein-labeled, E. coli, a fluorescein-labeled K. pneumoniae specific PNA probe and a Texas Red-label, P. aeruginosa specific PNA probe is added to a smear prepared from a positive blood culture. Hybridization is performed at 55°C for 90 minutes. The hybridization is followed by a water rinse at 55°C to remove the cover slips followed by a wash at 55°C for 30 minutes with a stringent Wash Solution. Finally, the smear is mounted with Mounting Medium and examined by fluorescence microscopy.

M. Performance Characteristics (if/when applicable):

1. Analytical performance:

a. Precision/Reproducibility:

A reproducibility study for EK/P. aeruginosa PNA FISH assay was performed by using ten reference Gram negative rods, once per day with positive and negative controls, over a period of three days at three different sites, by one operator at each site. Results showed 100% precision and reproducibility between and within sites.

b. Linearity/assay reportable range:

Not applicable

c. Traceability, Stability, Expected values (controls, calibrators, or methods):

Positive and negative control slides were performed at each testing site. All results were as expected.

d. Detection limit:

10⁵ CFU/mL

e. Analytical specificity:

The analytical specificity of the EK/P. aeruginosa PNA FISH™ was determined by BLAST search and sequence alignments and experimentally by testing of well characterized laboratory and reference strains comprising of 22 E. coli, 17 K. pneumoniae and 24 P. aeruginosa, 74 additional Gram negative, including anaerobes, 13 Gram positive organisms and 7 yeasts. All E. coli, K. pneumoniae and P. aeruginosa were correctly identified. Brevundimonas diminuta, Herbaspirillum huttiense, Pseudomonas nitroreducens and Pseudomonas fulva cross reacted to create a red signal; Shigella spp,

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(serogroup A, B, C, or D), Escherichia fergusonii and Escherichia albertii cross reacted to create a green signal.

Interference

A study consisting of 15 Gram negative rods were tested on BACTEC Plus blood culture bottles for the interference of resin. No interferences were observed. Current peer-reviewed publications indicated that sodium polyanetholesulfonate (SPS) or charcoal does not cause interference with PNA FISH assays.

f. Assay cut-off:
Not applicable

2. Comparison studies:

a. Method comparison of device to conventional methods, as the reference method:
Performance results compare to routine Vitek2 identifications, following subculture.

b. Matrix comparison:
Not applicable

3. Clinical studies:

a. Clinical Sensitivity:
Clinical Studies were conducted at four sites in the United States and Europe, directly on blood culture bottles containing Gram negative rods (GNR). A total of 240 GNR-positive blood bottles, from two commercial continuously monitoring blood culture systems (BacT/Alert and BACTEC) were included in the study. Performance results compare to routine identifications, following subculture, was summarized below.

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Performance Data for EK/P. aeruginosa PNA FISH

| Study | Sensitivity
EK | Sensitivity
P. aeruginosa | Specificity | Blood Culture System |
| --- | --- | --- | --- | --- |
| A | 100% (26/26) | 100% (11/11) | 92.3% (12/13) | BacT/Alert |
| | 95% CI (89.1-100) | 95% CI (76.2-100) | 95% CI (64.0-99.8) | |
| B | 100% (47/47) | 88.9% (8/9) | 100% (18/18) | BacT/Alert |
| | 95% CI (93.8-100) | 95% CI (51.8-99.7) | 95% CI (84.7-100) | |
| C | 100% (31/31) | 92.3% (12/13) | 94.4% (17/18) | BACTEC |
| | 95% CI (90.8-100) | 95% CI (64.0-99.8) | 95% CI (72.7-99.9) | |
| D | 100% (40/40) | 100% (2/2) | 100% (13/13) | BacT/Alert |
| | 95% CI (92.8-100) | 95% CI (22.4-100) | 95% CI (79.4-100) | |
| Total | 100% (144/144) | 94.3% (33/35) | 95.9% (60/62) | |
| | 95% CI (97.9-100) | 95% CI (80.8-99.3) | 95% CI (88.8-99.6) | |

b. Clinical specificity:
Refer to table above

c. Other clinical supportive data (when a. and b. are not applicable):
Not applicable

4. Clinical cut-off:
Not applicable

5. Expected values/Reference range:
E. coli/K. pneumoniae cells: multiple bright green fluorescent rods in multiple fields
P. aeruginosa cells: multiple bright red fluorescent rods in multiple fields.

The expected E. coli, K. pneumoniae and P. aeruginosa positive result rate for Gram-negative rods positive blood culture bottles are approximately 37%, 18% and 13%, respectively.

N. Proposed Labeling:
The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10.

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