C. ALBICANS/C. GLABRATA PNA FISH

K092784 · Advandx, Inc. · NZS · Mar 12, 2010 · Microbiology

Device Facts

• Record ID: K092784
• Device Name: C. ALBICANS/C. GLABRATA PNA FISH
• Applicant: Advandx, Inc.
• Product Code: NZS · Microbiology
• Decision Date: Mar 12, 2010
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.2660
• Device Class: Class 1

Indications for Use

C. albicans/C. glabrata PNA FISH™ is a qualitative nucleic acid hybridization assay intended for identification of Candida albicans/C.glabrata on smears made from positive blood cultures containing yeast observed on Gram stain or other microbiological stains. Subculturing of positive blood cultures is necessary for susceptibility testing and/or differentiation of mixed growth.

Device Story

Qualitative nucleic acid hybridization assay; identifies Candida albicans/C. glabrata in yeast-positive blood cultures. Input: smear prepared from positive blood culture bottle. Process: heat/methanol/flame fixation; hybridization with fluorescein-labeled PNA probes (30 minutes at 55°C); wash; mounting. Output: visual identification via fluorescent microscope; C. albicans appears as bright green yeast; C. glabrata appears as bright red yeast. Used in clinical microbiology laboratories; performed by trained laboratory personnel. Results provide rapid identification of yeast species, enabling targeted clinical decision-making compared to conventional culture-based methods.

Clinical Evidence

No clinical data provided in the document; the submission relies on analytical performance characteristics typical of a qualitative nucleic acid hybridization assay.

Technological Characteristics

Fluorescence in situ hybridization (FISH) assay using peptide nucleic acid (PNA) probes. Qualitative detection of ribosomal RNA targets. Requires fluorescence microscopy for visualization. Standalone diagnostic test kit.

Indications for Use

Indicated for use as an aid in the diagnosis of C. albicans and/or C. glabrata fungemia in patients with yeast-positive blood cultures.

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.

Submission Summary (Full Text)

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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY

A. 510(k) Number:
K092784

B. Purpose for Submission:
To obtain a SE determination for a modification of the assay procedure for C.albican/C.glabrata PNA FISH. The specific modifications are: elimination of the 5-10 minutes ethanol step in smear preparation; a reduction of the hybridization time from 90 minutes to 30 minutes.

C. Measurand:
C. albicans/C.glabrata specific 26S ribosomal RNA

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

E. Applicant:
AdvanDx, Inc.

F. Proprietary and Established Names:
C albicans/C.glabrata PNA FISH™ Candida albicans/C.glabrata Culture Identification Kit

G. Regulatory Information:
| Product Code | Classification | Regulation Section | Panel |
| --- | --- | --- | --- |
| NZS | Class 1 | 21 CFR 866.2660 | 83 Microbiology |

H. Intended Use:

1. Intended use(s):
C. albicans/C. glabrata PNA FISH™ is a qualitative nucleic acid hybridization assay intended for identification of Candida albicans/C.glabrata on smears made

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from positive blood cultures containing yeast observed on Gram stain or other microbiological stains. Subculturing of positive blood cultures is necessary for susceptibility testing and/or differentiation of mixed growth.

2. Indication(s) for use:

C. albicans/C. glabrata PNA FISH™ is a qualitative nucleic acid hybridization assay intended for identification of Candida albicans/C. glabrata on smears made from positive blood cultures containing yeast observed on Gram stain or other microbiological stains. Subculturing of positive blood cultures is necessary for susceptibility testing and/or differentiation of mixed growth.

3. Special conditions for use statement:

Prescription use only.

4. Special instrument requirements:

AdvanDx Teflon-coated Microscope Slides. (Cat. AC001) A fluorescent microscope equipped with an AdvanDx Dual Band Filter (Cat. No. AC003)

I. Device Description:

The C. albicans/C. glabrata PNA FISH™ Culture Identification Kit contains a 3 mL bottle of fixation solution, a 1.5 mL bottle of fluorescein-labeled PNA probe in hybridization solution, a 50 mL bottle of concentrated wash solution, which must be diluted prior to use, and a 3 mL bottle of mounting medium. The one-well, Teflon-coated microscope slides, glass cover slips and the external quality control organism slides are sold separately. User prepared quality control organism slides are acceptable. After processing, the slides must be examined within two hours by using a fluorescent microscope equipped with a dual band filter

J. Substantial Equivalence Information:

1. Predicate device name:

C.albicans PNA FISH™

2. Predicate K numbers

K062461

3. Comparison with predicate:

2

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| | Similarities | |
| --- | --- | --- |
| Technology | Fluorescence In Situ Hybridization (FISH) using protein nucleic acid (PNA) probe | Same |
| Sample | Yeast Positive blood culture | Same |
| Interpretation of Results | Qualitative Fluorescence microscope | Same |
| Differences | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Fixed smear treatment | None | Ethanol for 10 minutes and air dried |
| Hybridization at 55°C | 30 minutes | 90 minutes |

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

Not applicable

# L. Test Principle:

One drop of fluorescein-labeled, C. albicans/C.glabrata-specific PNA probe is added to a methanol, heat, or flame fixed smear, prepared from positive liquid blood culture bottles. Hybridization is performed during a $30 + / - 5$ minute incubation at $55 + / - 1^{\circ}\mathrm{C}$ , in an incubator or on a slide warmer. The slide is examined by fluorescent microscopy within two hours of staining. C. albicans is identified as multiple bright green fluorescent yeast cells in multiple fields and C.glabrata is identified as a multiple bright red fluorescent yeast cells in multiple fields.

# M. Performance Characteristics (if/when applicable):

# 1. Analytical performance:

# a. Precision/Reproducibility:

A reproducibility study for C. albicans/C. glabrata PNA FISH™ assay was performed by using ten reference yeast samples, once per day with positive and negative controls, over a period of three days at three different sites, by at least two different operators at each site. Results showed $100\%$ precision and reproducibility between and within sites.

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Summary of Reproducibility Results by Day Across Sites

| | DAY 1 | DAY 2 | DAY 3 | Total Agreement |
| --- | --- | --- | --- | --- |
| Positive Agreement Green | 63/63 | 63/63 | 63/63 | 100 % (189/189) |
| Negative Agreement Red | 63/63 | 63/63 | 63/63 | 100% (189/189) |
| Negative Agreement | 63/63 | 63/63 | 63/63 | 100% (189/189) |
| Total Agreement | 100%(189/189) | 100% (189/189) | 100% (189/189) | 100% (567/567) |
| Positive/Negative Control | 18/18 | 18/18 | 18/18 | |

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:

The claimed detection limit for C. albicans/C. glabrata in blood cultures was determined to be approximately $1 \times 10^{5}$ colony forming units (CFU) per mL by serial dilutions of a C. albicans/C. glabrata positive culture. This is consistent with the analytical sensitivity of slide-based staining techniques and is not limited by the test itself, but rather by the general requirement for $1 \times 10^{5}$ CFU/mL for interpretation by standard light microscopy.

e. Analytical specificity:

Specificity of C. albicans/C. glabrata PNA FISH probe was evaluated using cultures of 57 laboratory and reference strains comprising of Candida species, other closely related species and a variety of other frequently isolated organisms. All (20/20) C. albicans strain were green-positive, and all (14/14) C. glabrata strains were red-positive. Candida nivariensis, Candida bracarensis and Kluyveromyces delphensis were red-and two strains of Candida orthopsilosis were green-positive. All others (18/18) fungal and bacteria strains were negative.

Co-infection studies were conducted using concentrations of C. albicans and

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C. glabrata at CFU of $10^{6}$ . The C. albicans/C. glabrata PNA probe sequence is highly specific for identification of C. albican and C. glabrata.

f. Assay cut-off:

Not applicable

# 2. Comparison studies:

a. Method comparison with predicate device:

The performance of C. albicans/C. glabrata PNA FISH™ was evaluated using two different automated blood culture media systems at multiple sites. The data demonstrates that C. albicans/C. glabrata PNA FISH™ is compatible with two of the three major blood culture systems, and results from testing are comparable to results obtained by conventional methods. The results are displayed in the tables below.

Summary of Reproducibility Results by Sites Across 3 Days

| | Site 1 | Site 2 | Sites 3 | Total Agreement |
| --- | --- | --- | --- | --- |
| Positive Agreement Green | 27/27 | 27/27 | 27/27 | 100 % (81/81) |
| Negative Agreement Red | 27/27 | 27/27 | 27/27 | 100% (81/81) |
| Negative Agreement | 45/45 | 45/45 | 45/45 | 100% (135/135) |
| Total Agreement | 100% (99/99) | 100% (99/99) | 100% (99/99) | 100% (297/297) |

Performance Data for C. albicans/C. glabrata PNA FISH (new) Vs. C.albicans/C. glabrata (listed) on Yeast-positive Blood Culture Bottles (Clinical and Yeast Seeded Samples)

| Study | Positive Agreement C. albicans | Positive Agreement C. glabrata | Negative Agreement | Blood Culture system |
| --- | --- | --- | --- | --- |
| A | 100% (21/21) | 100% (9/9) | 100% (20/20) | BACTEC |
| B | 100% (21/21) | 100% (13/13) | 100% (16/16) | BacT/ALERT |
| C | 100% (5/5)* | 100% (6/6)* | 100% (15/15) | BACTEC |
| Total | 100% (47/47)95% CI (93.8-100) | 100% (28/28)95% CI (89.9-100) | 100% (51/51)95% CI (94.3-100) | N=126 |

*One bottle contained both C. albican and C. glabrata

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b. Matrix comparison: Not applicable

3. Clinical studies:
a. Clinical Sensitivity: Not applicable
b. Clinical specificity: Not applicable
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:
The expected C. albicans/C. glabrata positive result rate from yeast positive blood culture bottles is 25% - 40%, respectively depending on institutional and patient population. There is no Reference range for this assay. It is a qualitative assay that produces a color change. Red indicates C. glabrata, and green indicates C. albicans

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

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