CHROMID CARBA agar (CARB)

K181092 · Biomerieux S.A. · JSO · Jul 6, 2018 · Microbiology

Device Facts

• Record ID: K181092
• Device Name: CHROMID CARBA agar (CARB)
• Applicant: Biomerieux S.A.
• Product Code: JSO · Microbiology
• Decision Date: Jul 6, 2018
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.1700
• Device Class: Class 2

Intended Use

CHROMID® CARBA agar is a selective and differential chromogenic medium that is intended for the qualitative detection and presumptive identification of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae in rectal swab specimens from patients at risk of colonization. CHROMID® CARBA agar is intended as an aid in the detection, identification of colonization and control of these bacteria in a healthcare setting. Rectal swabs are inoculated directly onto CHROMID® CARBA agar without enrichment and results can be interpreted after incubation for 18-24 hours. Presumptive carbapenemase-producing colonies of E. coli appear pink to burgundy and those of K. pneumoniae appear blue-green or blue-grey. Other organisms besides carbapenemase-producing E. coli and K. pneumoniae can also grow on CHROMID® CARBA agar with colonies that appear pink to burgundy or blue-grey. Sub-culture to non-selective medium is required to confirm organism identity, for antimicrobial susceptibility testing, confirmation of carbapenemase production and epidemiological typing. A lack of growth or the absence of pink to burgundy or blue-green to blue-grey colonies does not preclude the carriage of carbapenemase producing organisms.

Device Story

CHROMID® CARBA agar is a selective/differential chromogenic culture medium; used for screening rectal swabs from patients at risk of carbapenemase-producing E. coli and K. pneumoniae colonization. Input: rectal swab specimens inoculated directly onto agar without enrichment. Principle: nutritive base with peptones, antibiotics, and 3 chromogenic substrates; enables presumptive identification via spontaneous colony coloration (pink-to-burgundy for E. coli; blue-green/blue-grey for K. pneumoniae) after 18-24 hours incubation. Output: visual colony growth/coloration. Used in clinical laboratories; interpreted by microbiologists. Results are presumptive; requires sub-culture to non-selective media for confirmation, antimicrobial susceptibility testing, and epidemiological typing. Benefits: aids in rapid identification and control of carbapenemase-producing bacteria in healthcare settings.

Clinical Evidence

Prospective clinical study (n=709) compared CHROMID® CARBA agar to CDC enrichment culture method. For E. coli: 99.7% NPA (95% CI 99.0-99.9%). For K. pneumoniae: 84.3% PPA (95% CI 72.0-91.8%) and 97.7% NPA (95% CI 96.3-98.6%). Contrived sample study (n=210) showed 80.0% PPA/98.9% NPA for E. coli and 96.6% PPA/91.1% NPA for K. pneumoniae. Analytical studies included LOD (1.5x10^3 CFU/mL), interfering substances, cross-reactivity, and mixed infection testing.

Technological Characteristics

Selective/differential culture medium containing peptones, antimicrobial agents, and chromogenic substrates (β-glucuronidase/β-galactosidase for E. coli; β-glucosidase for K. pneumoniae). Form factor: agar plate. Incubation: 18-24 hours at 35±2°C, aerobic. Standalone use; no instrumentation required.

Indications for Use

Indicated for qualitative detection and presumptive identification of carbapenemase-producing E. coli and K. pneumoniae in rectal swab specimens from patients at risk of colonization. Prescription use only.

Regulatory Classification

Identification

A culture medium for antimicrobial susceptibility tests is a device intended for medical purposes that consists of any medium capable of supporting the growth of many of the bacterial pathogens that are subject to antimicrobial susceptibility tests. The medium should be free of components known to be antagonistic to the common agents for which susceptibility tests are performed in the treatment of disease.

Predicate Devices

• bioMérieux CHROMID VRE agar (K091025)

Submission Summary (Full Text)

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Image /page/0/Picture/0 description: The image contains the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo, which is a blue square with the letters "FDA" in white. To the right of the blue square is the text "U.S. FOOD & DRUG ADMINISTRATION" in blue.

July 6, 2018

bioMérieux SA Asa Karlsson Sr. Regulatory Affairs Manager 376 Chemin de l'Orme Marcy l'Etoile, 69280 Fr

Re: K181092

Trade/Device Name: CHROMID CARBA agar (CARB) Regulation Number: 21 CFR 866.1700 Regulation Name: Culture medium for antimicrobial susceptibility tests Regulatory Class: Class II Product Code: JSO Dated: April 24, 2018 Received: April 25, 2018

Dear Asa Karlsson:

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 Part 801 and Part 809); medical device 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.

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K181092

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/) and CDRH Learn (http://www.fda.gov/Training/CDRHLearn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (http://www.fda.gov/DICE) for more information or contact DICE by email ([e-mail]) or phone [phone] or 301-796-7100).

Sincerely,

Ribhi Shawar -S
For

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

Enclosure

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## Indications for Use

510(k) Number (if known) K181092

Device Name CHROMID® CARBA agar (CARB)

#### Indications for Use (Describe)

CHROMID® CARBA agar is a selective and differential chromogenic medium that is intended for the qualitative detection and presumptive identification of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae in rectal swab specimens from patients at risk of colonization. CHROMID® CARBA agar is intended as an aid in the detection, identification of colonization and control of these bacteria in a healthcare setting.

Rectal swabs are inoculated directly onto CHROMID® CARBA agar without enrichment and results can be interpreted after incubation for 18-24 hours. Presumptive carbapenemase-producing colonies of E. coli appear pink to burgundy and those of K. pneumoniae appear blue-green or blue-grey.

Other organisms besides carbapenemase-producing E. coli and K. pneumoniae can also grow on CHROMID® CARBA agar with colonies that appear pink to burgundy or blue-grey. Sub-culture to non-selective medium is required to confirm organism identity, for antimicrobial susceptibility testing, confirmation of carbapenemase production and epidemiological typing.

A lack of growth or the absence of pink to burgundy or blue-grey colonies does not preclude the carriage of carbapenemase producing organisms.

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

| <span style="font-family: Arial, sans-serif;">☑</span> Prescription Use (Part 21 CFR 801 Subpart D) | □ Over-The-Counter Use (21 CFR 801 Subpart C) |
|-----------------------------------------------------------------------------------------------------|-----------------------------------------------|
|-----------------------------------------------------------------------------------------------------|-----------------------------------------------|

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## SECTION 029. 510(k) SUMMARY

#### 510(k) SUMMARY

CHROMID® CARBA agar

#### A. 510(k) Submission Information:

| 510(k) Submission: | K181092 |
|--------------------------------------------------|-------------------------------------------------------------------------------------------|
| Submitter's Name: | bioMerieux SA |
| Address: | 376 Chemin de l'Orme<br>69280 Marcy l'Etoile, FRANCE |
| Contact Person: | Asa Karlsson<br>Sr. Regulatory Affairs Manager |
| Phone Number: | [phone] |
| Email: | [e-mail] |
| 510(k) Summary | |
| Date of Preparation: | June 28, 2018 |
| <b>B. Device Name:</b> | |
| Formal/Trade Name: | CHROMID® CARBA agar |
| Classification Name: | 21 CFR 866.1700<br>Culture Medium for Antimicrobial Susceptibility Test |
| Product Code | JSO<br>Culture Media, Antimicrobial Susceptibility Test, Excluding<br>Mueller Hinton Agar |
| Common Name: | CHROMID® CARBA agar (CARB) |
| C. Predicate Device: CHROMID® VRE agar (K091025) | |

## D. 510(k) Summary:

Intended Use:

CHROMID® CARBA agar is a selective and differential chromogenic medium that is intended for the qualitative detection and presumptive identification of carbapenemaseproducing Escherichia coli and Klebsiella pneumoniae in rectal swab specimens from

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Traditional 510(k) Submission

patients at risk of colonization. CHROMID® CARBA agar is intended as an aid in the detection, identification of colonization and control of these bacteria in a healthcare setting.

Rectal swabs are inoculated directly onto CHROMID® CARBA agar without enrichment and results can be interpreted after incubation for 18-24 hours. Presumptive carbapenemase-producing colonies of E. coli appear pink to burgundy and those of K. pneumoniae appear blue-green or blue-grey.

Other organisms besides carbapenemase-producing E. coli and K. pneumoniae can also grow on CHROMID® CARBA agar with colonies that appear pink to burgundy or bluegreen to blue-grey. Sub-culture to non-selective medium is required to confirm organism identity, for antimicrobial susceptibility testing, confirmation of carbapenemase production and epidemiological typing.

A lack of growth or the absence of pink to burgundy or blue-green to blue-grey colonies does not preclude the carriage of carbapenemase producing organisms.

#### Indications for use:

See Intended Use

### Device Description:

CHROMID® CARBA agar consists of a nutritive base combining different peptones, 3 chromogenic substrates and antibiotics. These components enable the screening and presumptive identification of E. coli: spontaneous coloration (pink to burgundy) of strains producing ß-glucuronidase (ß-GUR) and/or ß-galactosidase (ß-GAL) and K. pneumoniae: spontaneous blue-green to bluish-grey coloration of strains producing ß-glucosidase (ß-GLU) from rectal swabs.

#### Substantial Equivalence:

The similarities of CHROMID® CARBA agar when compared to the predicate device are described in the following table:

| Category | Predicate Device<br>bioMerieux SA<br>CHROMID® VRE agar<br>K091025 | Proposed Device<br>bioMerieux SA<br>CHROMID® CARBA agar<br>K181092 | Substantially equivalent |
|---------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Similarities | | | |
| Classification, and<br>Product code | Class II, 21 CFR 866.1700<br>JSO | Class II, 21 CFR 866.1700<br>JSO | Equivalent |
| Intended Use | CHROMID® VRE agar is a<br>selective and differential<br>chromogenic medium containing<br>8 µg/mL vancomycin, for the<br>qualitative detection of<br>Enterococcus faecium and E.<br>faecalis showing acquired<br>vancomycin resistance (VRE) in<br>stool specimens. CHROMID®<br>VRE agar can be used as an aid<br>to identify, prevent and control | CHROMID® CARBA agar is a<br>selective and differential<br>chromogenic medium that is<br>intended for the qualitative<br>detection and presumptive<br>identification of carbapenemase-<br>producing Escherichia coli and<br>Klebsiella pneumoniae in rectal<br>swab specimens from patients at<br>risk of colonization.<br>CHROMID® CARBA agar is | Equivalent<br>Both agars are designed to<br>detect resistance<br>mechanisms but for<br>different antimicrobial<br>species. |
| | Predicate Device | Proposed Device | |
| Category | bioMerieux SA | bioMerieux SA | Substantially equivalent |
| | CHROMID® VRE agar | CHROMID® CARBA agar | |
| | K091025 | K181092 | |
| | VRE colonization in healthcare | intended as an aid in the | |
| | stings. | detection, identification of | |
| | | colonization and control of these | |
| | CHROMID® VRE agar is not | bacteria in a healthcare setting. | |
| | intended to diagnose VRE<br>infection nor to guide or monitor | Rectal swabs are inoculated | |
| | treatment for infections. | directly onto CHROMID® | |
| | Subculture to non-selective | CARBA agar without | |
| | media (e.g., trypticase soy agar | enrichment and results can be<br>interpreted after incubation for | |
| | with 5% sheep blood) is needed | 18-24 hours. Presumptive | |
| | for further identification, | carbapenemase-producing | |
| | susceptibility testing and<br>epidemiological typing. | colonies of E. coli appear pink to | |
| | | burgundy and those of K. | |
| | | <i>pneumoniae</i> appear blue-green<br>or blue-grey. | |
| | | | |
| | | Other organisms besides | |
| | | carbapenemase-producing <i>E.</i><br><i>coli</i> and <i>K. pneumoniae</i> can also | |
| | | grow on CHROMID® CARBA | |
| | | agar with colonies that appear | |
| | | pink to burgundy or blue-green | |
| | | to blue-grey. Sub-culture to non- | |
| | | selective medium is required to | |
| | | confirm organism identity, for<br>antimicrobial susceptibility | |
| | | testing, confirmation of | |
| | | carbapenemase production and | |
| | | epidemiological typing. | |
| | | A lack of growth or the absence | |
| | | of pink to burgundy or blue-<br>green to blue-grey colonies does | |
| | | not preclude the carriage of | |
| | | carbapenemase producing | |
| | | organisms. | |
| Test method | Manual, culture media | Manual, culture media | Identical |
| Method of | Direct inoculation of the sample | Direct inoculation of the sample | Identical |
| inoculation | type without enrichment. | type without enrichment. | |
| Storage of the | 2-8° C in their box until expiry | 2-8° C in their box until expiry | Identical |
| device | date. | date. | |
| | Outside the box, plates can be | Outside the box, plates can be | |
| | stored for 2 weeks in the dark in<br>the cellophane sachet at 2-8° C. | stored for 2 weeks in the dark in<br>the cellophane sachet at 2-8° C. | |
| | | | |
| Formula | Formula / Liter | Formula/ Liter | Equivalent |
| | Casein and meat peptone | Casein and meat peptone | |
| | (bovine or porcine) ........ 18g | (bovine or porcine) ........ 13g | The formulas contain |
| | Heart peptone ........ 3g | Soy peptone ........ 5g | similar ingredients and have |
| | Corn starch ........ 1g | Carbohydrates ........ 1g | |
| Category | Predicate Device<br>bioMerieux SA<br>CHROMID® VRE agar<br>K091025 | Proposed Device<br>bioMerieux SA<br>CHROMID® CARBA agar<br>K181092 | Substantially equivalent |
| | Sodium chloride...............6g<br>Agar........................15g<br>Selective mixture........28.8mg<br>Chromogenic mixture.....0.13g<br>Purified water................1L<br><br>Final pH: 7.2 | L-Tryptophan................0.9g<br>Phosphate buffer .............1g<br>Nutrient mixture...............2g<br>Agar........................18g<br>Selective mixture............1.35g<br>Chromogenic mixture......1.23g<br>Purified water................1L<br><br>Final pH: 7.4 | a similar final pH.<br><br>Both formulas can be adjusted and/or supplemented according to the performance criteria required. |
| <b>Differences</b> | | | |
| Analytes | Vancomycin resistant <i>E. faecium</i><br>and <i>E. faecalis</i> . | Carbapenemase-producing <i>E. coli</i><br>and <i>K. pneumoniae</i> . | Different target species and<br>antimicrobial resistance<br>phenotypes. |
| Specimen Types | Swabs<br>(stools) | Swabs<br>(rectal) | Different specimen types |
| Interpretation of<br>positive results | Observe bacterial growth and the<br>appearance of colonies.<br><br>Positive <i>E. faecium</i> : Violet<br>colonies.<br><br>Positive <i>E. faecalis</i> : Blue to<br>green colonies. | Observe bacterial growth and the<br>appearance of colonies.<br><br>Presumptive positive <i>E. coli</i> :<br>Pink to burgundy colonies.<br><br>Presumptive positive <i>K.<br/>pneumoniae</i> : Blue-green to<br>bluish-grey colonies. | Equivalent<br><br>Different color changes<br>depending on bacterial<br>species provide a visual<br>interpretation of positive<br>results.<br><br>Positive results obtained on<br>CHROMID® CARBA agar<br>are presumptive. |
| Incubation time<br>and conditions | Incubate at 35-37°C in aerobic<br>conditions.<br><br>Examined for growth after 24 to<br>48 hours. | Incubate at 35-37°C in aerobic<br>conditions.<br><br>Examined for growth after 18 to<br>24 hours. | Identical.<br><br>Potential extended<br>incubation time for the<br>predicate. |

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## CHROMID® CARBA agar Traditional 510(k) Submission

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### CHROMID® CARBA agar Traditional 510(k) Submission

Both the devices use a selective mixture for the detection of resistance mechanisms and a chromogenic mixture for the presumptive identification of the bacterial species. Their formulas and method of inoculation on the agar are similar. The differences between the new device and the predicate device are related to the bacterial species and antimicrobial resistance mechanisms detected and the associated colony colors, the specimen type and incubation time. The performance data presented in this submission support a substantial equivalence

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#### Performance Characteristics:

#### Analytical Studies

The following analytical studies were conducted to evaluate the performance of the CHROMID® CARBA agar: Interfering Substances, Recovery Study (Limit of Detection), Cross Reactivity (Analytical Specificity), Challenge Testing (Analytical Reactivity), Mixed Infection and Incubation Time. All analytical performance studies demonstrated acceptable results.

Interfering Substances: No interference was observed with 21 interfering substances including Zinc Oxide, Pramocaine hydrochloride, Miconazole nitrate, K-Y Jelly, Loperamide hydrochloride, Playtex Personal wipes, Witch Hazel, Diosmectite, Talc, K-Y Liquibeads vaginal moisturizer, Vaseline, Glycerol, Phenylephrine HCl, Trojan Enz condoms, Physiological saline, Bisacodyl, Ispaghula husk, Benzocaine + Resorcinol, Ruscoside + Lidocaine hydrochloride + Prednacinolone acetonide, Hydrocortisone and Human Blood.

Recovery Study (Limit of Detection (LOD)): Two well-characterized KPC strains K. pneumoniae ATCC® 1705™ and E. coli ATCC® 2340™ were tested to determine the lowest number of CFU/mL detected on CHROMID® CARBA agar. After 18 to 24 hours of incubation, the lowest dilution for the detection (Limit of Detection (LOD)) of both strains was 1.5x103 CFU/mL.

Cross Reactivity (Analytical Specificity): To evaluate the analytical specificity of CHROMID® CARBA agar, testing was performed with high concentrations (10° CFU/mL; 1000 times the LOD) of 59 target and non-target organisms. The strains tested included bacterial and fungal species encountered in stools, CPE and strains of E. coli and K. pneumoniae that produced other carbapenemases besides KPC type enzyme. After 18 to 24 hours of incubation, growth and colony coloration were analyzed.

- Sixteen CPE grew with pink to burgundy or blue-grey colonies:
Six KPC strains belonging to the following species: three C. freundii (blue-grey), one
- P. rettgerii (blue-green), one E. cloacae (blue-green) and one K. aerogenes [E. aerogenes| (blue-green),
- . Four strains of K. pneumoniae with a resistant mechanism other than KPC: one VIM,
one IMP, one OXA-48, one NDM (all blue-green),
- . Three strains of E. coli with a resistant mechanism other than KPC: one NDM, one VIM, one IMP (all pink-to burgundy)
- . Two strains of M. morganii with NDM (both blue-green),
- One strain of S. marcescens with SME (blue-green).

Pseudomonas aeruginosa (VIM), Stenotrophomonas maltophilia (VIM), Pseudomonas putida and Acinetobacter baumanii (NDM) grew on CHROMID® CARBA agar but without a characteristic coloration (colorless).

See Limitations section in the package insert.

Challenge Testing (Analytical Reactivity): Fifty-two well-characterized KPC-EK strains were tested on CHROMID® CARBA agar using a calibrated inoculum at 4.5x109 CFU/mL (3 times the LOD).

After 18 to 24 hours of incubation, all the K. pneumoniae strains were recovered with characteristic blue-green color. Among the 11 E. coli studied, 9 of them grew with a

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Traditional 510(k) Submission

characteristic burgundy color. The two other E. coli failed to grow; of these, one had an MIC in the susceptible range for ertapenem and was intermediate for imipenem and meropenem and the other was susceptible to all three carbapenems tested.

Mixed Infection: Four carbapenemase-producing strains including two E. coli and two K. pneumoniae that each harbored KPC carbapenemase were tested at three times the LOD value in mixtures with other target and non-target organisms at 104 to 108 CFU/mL:

- one carbapenem non-susceptible carbapenemase-negative K. pneumoniae, .
- . one carbapenem non-susceptible Pseudomonas aeruginosa with VIM carbapenemase,
- . one carbapenem non-susceptible E. coli with NDM carbapenemase,
- one carbapenem susceptible K. pneumoniae.
- one carbapenem non-susceptible Enterobacter cloacae with KPC carbapenemase •
- one carbapenem non-susceptible Morganella morganii with NDM carbapenemase
- . one carbapenem non-susceptible Providencia rettgeri with KPC carbapenemase

After 18 to 24 hours of incubation, the results obtained showed that when the competitive species were present at <108 CFU/mL, colonies of the four KPC producing target organisms grew with the characteristic color (either pink-burgundy for E. coli or bluegreen/blue-grey for K. pneumoniae). However, when present at 108 CFU/mL, KPCproducing E. cloacae, NDM-producing M. morganii, VIM-producing P. aeruginosa and NDM-producing E. coli inhibited or masked the growth of one or more KPC-producing target organisms. Please refer to the Limitations section of the package insert.

Incubation: Ten well-characterized isolates representing KPC-EK strains were tested every two hours between 16 and 28 hours of incubation at +35°C ± 2°C. The 10 strains were recovered with the expected colony colors after 16 hours of incubation and at each reading interval until 28 hours. The results of the study support the ability to recover carbapenemase-producing E. coli and K. pneumoniae on CHROMID® CARBA agar after incubation for 18-24 hours as stipulated in the device labeling.

#### Clinical Studies including Challenge, Reproducibility and Quality Control

Challenge Study: Fifty well characterized isolates were tested at one external site at two times the LOD in saline matrix.

The following strains were tested:

11 KPC negative strains: 6 K. pneumoniae and 5 E. coli,

39 KPC positive strains: 27 K. pneumoniae and 12 E. coli.

KPC positive strains included KPC-2, KPC-3 and KPC-4 gene variants.

Other resistance mechanisms were tested among the negative strains, including ESBL, AmpC and carbapenem non-susceptible carbapenemase-negative strains.

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#### Traditional 510(k) Submission

| K. pneumoniae | | | |
|---------------|-----------------|----------|-------|
| CHROMID® | Expected status | | |
| CARBA | Negative | Positive | Total |
| Negative | 23 | 0 | 23 |
| Positive | 0 | 27 | 27 |
| Total | 23 | 27 | 50 |

CHROMID® CARBA agar at 24 hours compared to expected status

Positive Percent Agreement 100.0% (95% CI: [87.5 - 100.0] % ) Negative Percent Agreement 100.0% (95% CI: [85.7 - 100.0] %)

| E. coli | | | |
|-------------------|-----------------|----------|-------|
| CHROMID®<br>CARBA | Expected status | | |
| | Negative | Positive | Total |
| Negative | 38 | 0 | 38 |
| Positive | 0 | 12 | 12 |
| Total | 38 | 12 | 50 |

Positive Percent Agreement 100.0% (95% CI: [75.8 - 100.0] %) Negative Percent Agreement 100.0% (95% CI: [90.8 - 100.0] %)

## Reproducibility and Quality Control:

Ten well-characterized isolates of carbapenemase-producing E. coli (4) and K. pneumoniae (6) that harbored blakec were tested in a blinded fashion in triplicate each day for five days at three sites, and by two different operators at each site. Isolates were tested at approximately the LOD target level and plates were read at 24 hours. The overall between-site reproducibility was 99.3% (894/900).

Quality Control was performed with three quality control organisms tested at each study site by CHROMID® CARBA agar on each day of comparative and reproducibility testing:

| Species | Strain | Expected Result | Agreement (%) |
|----------------------|------------------|-------------------------------|-------------------|
| <i>K. pneumoniae</i> | ATCC® BAA-1705TM | Blue-green/blue-grey colonies | 190/190<br>(100) |
| <i>E. coli</i> | ATCC® BAA-2340TM | Pink-burgundy colonies | 190/190<br>(100) |
| <i>K. pneumoniae</i> | ATCC® 700603TM | No growth | 189/190<br>(99.5) |

Overall, 569/570 (99.8%) of Quality Control test results for CHROMID® CARBA agar were as expected.

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### CLINICAL PERFORMANCE

#### Method Comparison

#### Prospective study on fresh clinical samples:

The performance of CHROMID® CARBA agar was evaluated at three external laboratories (2 in the US, 1 in Europe) using prospectively collected rectal swabs. A total of 1099 swabs from unique subjects were initially enrolled, of which 390 were excluded from the analysis of performance due to quality control failure (343), missing data (42) or questionable data reliability (5). Results from 709 swabs were therefore included in the analysis of performance. The characteristics of all colonies growing on CHROMID® CARBA medium (pink-to-burgundy, blue-green to blue-grey, colorless, and colors other than pink-to-burgundy or blue-green to blue-grey) at 18 to 24 hours were compared to the results obtained from the CDC enrichment culture method using selective Trypticase Soy broth, followed by subculture to MacConkey agar and phenotypic and genetic characterization of isolated lactose fermenting colonies.

Isolates from both the reference method and CHROMID® CARBA agar were identified biochemically and their carbapenemase status was determined by carbapenem susceptibility and CARBA NP testing, as well as PCR for carbapenemase resistance markers (Table 1).

| Carbapenem<br>MIC a | Carba NP Test | Carbapenemase<br>PCR b | Carbapenemase<br>Status |
|---------------------|---------------|------------------------|-------------------------|
| Non-susceptible | Positive | Positive | Positive |
| Non-susceptible | Positive | Negative | Negative |
| Non-susceptible | Negative | Positive | Positive |
| Non-susceptible | Negative | Negative | Negative |
| Susceptible | Positive | Positive | Positive |
| Susceptible | Positive | Negative | Negative |
| Susceptible | Negative | Positive | Negative c |
| Susceptible | Negative | Negative | Negative |

Table 1. Algorithm for determining carbapenemase status of isolates

a Non-susceptible: Intermediate or Resistant to one or more of the carbapenem antimicrobial agents tested (ertapenem, imipenem and meropenem)

b Multiplex PCR for blamp, blakpc, blandM, blaoxA-48 or blayM

C Phenotypic evidence of non-susceptibility to carbapenems in addition to a positive PCR result was required to establish the Carbapenemase Status as positive

The results of the study are presented in Tables 2 and 3 for carbapenemase-producing E. coli and K. pneumoniae, respectively.

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Traditional 510(k) Submission

| | | CDC Reference Culture Method | | |
|----------------------------|------------|------------------------------------|----------|-------|
| | | Positive | Negative | Total |
| CHROMID®<br>CARBA agar | Positive a | 0 | 2 c | 2 |
| | Negative b | 0 | 707 | 707 |
| | Total | 0 | 709 | 709 |
| Positive Percent Agreement | | Not applicable | | |
| Negative Percent Agreement | | 99.7% (707/709); 95% CI 99.0-99.9% | | |

Table 2. Detection of carbapenemase-producing E. coli in the Prospective Clinical Study

95% CI: 95% score confidence interval

- a Pink-burgundy colonies
- b No growth or colonies not pink-burgundy
- C Colonies from 1/2 specimens confirmed as carbapenem non-susceptible, carbapenemase negative K. pneumoniae; colonies from 1/2 specimens identified as Enterococcus faecalis

| | | Table 3. Detection of carbapenemase-producing K. pneumoniae in the Prospective | | | |
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