chromID® Strepto B agar is a selective chromogenic medium that is intended to aid in the qualitative determination of Group B Streptococcus (GBS) colonization in pregnant women. This medium supports the growth of, but does not differentiate between, hemolytic and non-hemolytic GBS strains. The test is performed on 18-24 hour LIM broth enrichments of vaginal/rectal swabs obtained from pregnant women. chromID® Strepto B agar results can be interpreted after 24 hours incubation with confirmation of characteristic GBS colonies from the media.

chromID® Strepto B agar is not intended to diagnose infection nor to guide or monitor treatment for infections. chromID® Strepto B agar does not provide susceptibility results. Subculture to non-selective media should be performed as needed for susceptibility testing. chromID® Strepto B agar is intended for use by laboratory health practitioners in a clinical laboratory.

Device Description

chromID Strepto B agar consists of a nutritive base combining different peptones, chromogenic substrates and antibiotics. These components enable the screening of S. agalactiae by the spontaneous appearance of pale pink to red colonies. Most other bacterial species and yeasts do not grow on this medium or do not produce typical colonies.

AI/ML Overview

Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance:

Performance Metric	Acceptance Criteria	Reported Device Performance (24 hours)
Sensitivity	Not explicitly stated in the document, but typically aims for high.	97.7% (95% CI: 94.3% - 99.1%)
Specificity	Not explicitly stated in the document, but typically aims for high.	92.1% (95% CI: 89.4% - 94.1%)
Analytical Reactivity	Detect GBS strains at low inoculum.	12/20 at 18h, 17/20 at 24h, 20/20 at 48h (at 10 CFU/ml)
Analytical Specificity	Most non-GBS organisms should not grow or produce non-typical colonies.	20/88 strains grew at 24h (3 with characteristic colonies); 30/88 grew at 48h (6 with characteristic colonies)
Mixed Infection (GBS recovery in presence of non-target)	GBS detected in presence of high levels of non-target organisms.	Both GBS strains detected at 24h in presence of 10^8 CFU/ml non-target (except for Streptococcus Group C); non-target organisms grew as non-characteristic colonies when diluted.
Incubation Time	Acceptable growth and characteristic colonies within specified timeframes.	8/10 GBS strains showed characteristic colonies at 24 hours.
Recovery	Lowest CFU/ml detected.	10^3 CFU/ml for both GBS strains.
Reproducibility	Expected results 100%.	100% of 990 times tested.
Quality Control	100% correct results for positive and negative controls.	100% correct for 107 times tested.
Interfering Substances	No interference or limited inhibition.	No interference for most; partial inhibition from naproxen sodium and topical agent.

Note: The document only provides the reported performance and implies that these values are acceptable as it concludes substantial equivalence. Explicit numerical acceptance criteria for sensitivity and specificity are not directly stated in the text.

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

Sample Size: A total of 681 vaginal/rectal specimens enriched in LIM broth were analyzed during the clinical trial.
Data Provenance: The data was collected from fresh clinical specimens at three external sites. This indicates that the data is prospective and originates from a clinical setting (likely within the USA, given the FDA filing).

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

The document does not explicitly state the number of experts or their specific qualifications (e.g., "radiologist with 10 years of experience").
It mentions that for the Reference Culture Method, "all suspicious colonies were screened to confirm or rule-out the presence of GBS using established laboratory methods: gram stain, catalase, PYR testing, and latex agglutination. VITEK® MS was also used to confirm the identification of GBS by the Reference Method." This implies that laboratory health practitioners (as stated in the intended use for the device) with relevant microbiology expertise were responsible for establishing the ground truth.

4. Adjudication Method for the Test Set:

The document does not describe an explicit adjudication method (like 2+1 or 3+1).
Instead, for the Reference Culture Method, it states that "all suspicious colonies were screened to confirm or rule-out the presence of GBS using established laboratory methods: gram stain, catalase, PYR testing, and latex agglutination. VITEK® MS was also used to confirm the identification of GBS by the Reference Method." This suggests a sequential confirmation process using multiple established laboratory tests to arrive at a confirmed ground truth, rather than an adjudication among independent readers.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done:

No, an MRMC comparative effectiveness study was not done.
This study evaluates a culture medium (chromID® Strepto B agar) against a "Reference Culture Method" for detecting Group B Streptococcus. It's a comparison of diagnostic methods, not human reader performance with and without AI assistance. Therefore, there is no effect size reported for human readers improving with AI.

6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) was Done:

Yes, a standalone performance evaluation was done. The "device" in this context is the chromID® Strepto B agar medium.
The clinical study directly compares the results obtained from the chromID® Strepto B agar (interpreting characteristic colonies after 24 hours, followed by confirmation) to a "Reference Culture Method." The reported sensitivity and specificity values represent the standalone performance of the chromID® Strepto B agar in identifying GBS from clinical specimens.
It's important to note that the device's intended use specifies "chromID® Strepto B agar results can be interpreted after 24 hours incubation with confirmation of characteristic GBS colonies from the media," indicating that a human laboratory health practitioner is always in the loop for confirmation, but the primary sensitivity and specificity reported directly reflect the medium's ability to selectively grow and display characteristic GBS colonies.

7. The Type of Ground Truth Used:

The ground truth used was expert consensus / established laboratory methods for microbiology.
The "Reference Culture Method" served as the gold standard, involving:
- Subculture to CNA agar.
- Screening suspicious colonies with gram stain, catalase, PYR testing, and latex agglutination.
- Confirmation with VITEK® MS.

8. The Sample Size for the Training Set:

The document does not explicitly mention a "training set" for the chromID® Strepto B agar. This is typical for traditional in-vitro diagnostic devices like culture media, which are developed and validated through analytical studies and then assessed in clinical studies, rather than "trained" like AI algorithms.
The design and formulation of the medium come from developmental work, but there isn't a "training set" in the machine learning sense.

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

As there is no explicit "training set" mentioned in the context of an algorithm, the concept of establishing ground truth for a training set is not directly applicable to this device description. The performance is assessed against established laboratory practices and known bacterial strains for analytical studies.

Summary

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Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002

January 27, 2017

BIOMERIEUX, INC. KAREN RUSSELL STAFF REGULATORY AFFAIRS SPECIALIST 595 ANGLUM ROAD HAZELWOOD MO 63042

Re: K163042

Trade/Device Name: ChromID® Strepto B Agar Regulation Number: 21 CFR 866.2360 Regulation Name: Selective culture medium Regulatory Class: I Product Code: POZ Dated: October 28, 2016 Received: October 31, 2016

Dear Ms. Russell:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food. Drug. and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21. Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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If you desire specific advice for your device on our labeling regulations (21 CFR Parts 801 and 809), please contact the Division of Industry and Consumer Education 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. 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 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 Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.

Sincerely yours,

Ribhi Shawar -A

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) K163042

Device Name chromID® Strepto B agar

Indications for Use (Describe)

chromID® Strepto B agar is a selective chromogenic medium that is intended to aid in the qualitative determination of Group B Streptococcus (GBS) colonization in pregnant women. This medium supports the growth of, but does not differentiate between, hemolytic GBS strains. The test is performed on 18-24 hour LIM broth enrichments of vaginal/rectal swabs obtained from pregnant women. chromID® Strepto B agar results can be interpreted after 24 hours incubation with confirmation of characteristic GBS colonies from the media.

chromID® Strepto B agar is not intended to diagnose infection nor to guide or monitor treatment for infections. chromID® Strepto B agar does not provide susceptibility results. Subculture to non-selective media should be performed as needed for susceptibility testing, chromID® Strepto B agar is intended for use by laboratory health practitioners in a clinical laboratory.

Type of Use (Select one or both, as applicable)
Research Use (Part 21 CFR 312, Subpart D)
Compassionate Use

|X Prescription Use (Part 21 CFR 801 Subpart D)

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

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SECTION 030. 510(k) SUMMARY

510(k) SUMMARY

chromID® Strepto B agar

A. 510(k) Submission Information:

Submitter's Name:	bioMérieux, Inc.
Address:	595 Anglum RoadHazelwood, MO 63042
Contact Person:	Karen RussellStaff Regulatory Affairs Specialist
Phone Number:Fax Number:	314-731-8639314-731-8689

Date of Preparation: October 28, 2016

B. Device Name:

Formal/Trade Name: chromID® Strepto B agar

Classification Name: 21 CFR 866.2360	Selective culture medium
--------------------------------------	--------------------------

Product Code POZ

Selective Culture Media Common Name:

C. Predicate Device: Modified Selective Streptococcus Agar (K881577)

D. 510(k) Summary:

Intended Use:

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chromID® Strepto B agar Traditional 510(k) Submission

Indications for use:

See Intended use

Device Description:

Substantial Equivalence:

The similarities and differences between chromID® Strepto B agar and the predicate device are described in the following table:

Category	Predicate DeviceAcumedia Manufacturers, Inc.Modified Selective Streptococcus AgarK881577	DevicebioMérieux, Inc.chromID® Strepto B agarK163042
Classification, and Product code	Class 1 21 CFR 866.2360JSI	Class 1 21 CFR 866.2360PQZ
Intended Use	Selective agar medium for the isolation and detection of pathogenic Streptococci.	chromID® Strepto B agar is a selective chromogenic medium that is intended to aid in the qualitative determination of Group B Streptococcus (GBS) colonization in pregnant women. This medium supports the growth of, but does not differentiate between, hemolytic and non-hemolytic GBS strains. The test is performed on 18-24 hour LIM broth enrichments of vaginal/rectal swabs obtained from pregnant women. chromID® Strepto B agar results can be interpreted after 24 hours incubation with confirmation of characteristic GBS colonies from the media. chromID® Strepto B agar is not intended to diagnose infection nor to guide or monitor treatment for infections. chromID® Strepto B agar does not provide susceptibility results. Subculture to non-selective media should be performed as needed for susceptibility testing. chromID® Strepto B agar is intended for use by laboratory health practitioners in a clinical laboratory.

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Category	Predicate DeviceAcumedia Manufacturers, Inc.Modified Selective Streptococcus AgarK881577	DevicebioMérieux, Inc.chromID® Strepto B agarK163042
Test method	Manual, culture media	Manual, culture media
Sample Types	Direct from Specimen	Vaginal/rectal swab enriched in Lim broth
Interpretationof positiveresults	For the detection of Streptococci, examinemedium for growth and hemolyticreactions (e.g. alpha-hemolysis, beta-hemolysis, or no hemolysis) after 18 - 24and 48 hours incubation.	For the detection of GBS, observebacterial growth and the appearance ofcolonies.Typical GBS colonies are pale pink tored.
QualityControl	Incubate at 35 ± 2°C. Examine for growthafter 18-24 hours.	Incubate in the dark at 35-37°C.Examine for growth after 24 hours. QCstrains: Streptococcus agalactiae ATCC12386 (positive control) andStaphylococcus aureus ATCC 6538(negative control)
Storage	2 - 30°C.	2 - 8°C

Both the devices use a selective media for the detection of Streptococci. Their formulas and method of inoculation are similar. The differences between chromID® Strepto B agar and the predicate device are related to the storage temperature, QC method, and interpretation of results.

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Performance Characteristics:

Analytical Studies

The following analytical studies were conducted to evaluate the performance of chromID® Strepto B medium: Analytical Reactivity (Challenge), Analytical Specificity (Cross Reactivity), Incubation Time, Interference, Recovery, and Mixed Infection. All analytical performance studies demonstrated acceptable results.

Recovery Study-Two well-characterized GBS strains (ATCC 12386, hemolytic and ATCC 13813, non-hemolytic) were tested to determine the lowest CFU/ml detected on chromID Strepto B medium. For both strains, the last dilution for which visible growth with characteristic colonies was observed was 103 CFU/ml.

Analytical Reactivity (Challenge)-A challenge set of 20 GBS strains (hemolytic and non-hemolytic) was inoculated on the chromID Strepto B medium at low inoculum (10) CFU/ml). After 18, 24 and 48 hours, 12/20, 17/20 and 20/20 strains were detected on the chromID® Strepto B medium, respectively.

Analytical Specificity (Cross Reactivity)-To evaluate the analytical specificity of the chromID StreptoB medium with non-GBS organisms, 88 strains representing bacterial and fungal species potentially encountered in vaginal/rectal samples were inoculated onto chromID® Strepto B medium at high inoculum (10° CFU/ml). After 24 hours of incubation, 20/88 strains grew on the medium with 3 strains producing characteristic colonies (Streptococcus Group C, Streptococcus mitis, and Klebsiella pneumoniae (KPC)). After 48 hours, 30/88 grew on the medium and 6 strains producing characteristic colonies (Streptococcus Group C, Streptococcus mitis, Streptococcus pyogenes, Streptococcus anginosus, Staphylococcus aureus (MRSA), Lactobacillus sakei).

Mixed Infection-This study was conducted to evaluate the performance of chromID Strepto B agar in recovering GBS in the presence of high levels of non-target organisms. Seven non-target organisms were tested in the study that included strains known to produce pale pink to red colonies on chromID® Strepto B medium from the Cross Reactivity Study. For those non-target strains yielding pink to red colonies on chromID® Strepto B medium, colony features were used to distinguish GBS from non-target organisms. Two GBS strains (one hemolytic and one non-hemolytic) were incubated at approximately 10° CFU/ml with each non-target organism. At 24 hrs, both GBS strains were detected in the presence of 108 CFU/ml of non-target organism, except in the presence of Streptococcus Group C (NCTC 8546). At this concentration (10° CFU/ml), 5/7 non-target organisms gave characteristic colonies when grown on chromID® Strepto B medium. The 2 GBS strains gave characteristic colonies as expected when tested in the presence of non-target organisms diluted below 108 CFU/ml (10-10' CFU/ml) at 24 hrs. It was noted that all non-target organisms incubated with GBS either did not grow or grew as non-characteristic colonies on chromID Strepto B agar when diluted from 10-10 CFU/ml.

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Incubation Ten (10) GBS strains (hemolytic and non-hemolytic) were inoculated on the chromID® Strepto B medium at low inoculum (10 CFU/ml). The growth and the presence of characteristic colonies were evaluated every hour across a range that represented different target times: 18 hrs (16-20 hrs), 24 hrs (21-28 hrs), and 48 hrs (44-52 hrs). The number of strains showing characteristic colonies ranged between 5/10 (at 16 and 17 hours) and 10/10 from 44 hours and after. At 24 hours, 8/10 GBS strains showed characteristic colonies.

Interfering Substances No interference was observed for vaginal fluid, amniotic fluid, sperm, whole blood, concentrated buffy coat and stool. Of the 15 interfering substances tested, two (naproxen sodium and topical agent) demonstrated partial inhibition of GBS growth on chromID StreptoB medium. Use of compounds containing the active ingredients below had an inhibitory effect on GBS growth that was unrelated to chromID StreptoB medium performance: nystatin (10" Ul/ml), hydrocortisone (0.625 mg/ml), aluminum hydroxide (2.125 mg/ml)/magnesium hydroxide (2.250 mg/ml), mesalazine ( 5 mg/ml), barium sulfate (5 mg/ml), esomeprazole (1 mg/ml), loperamide (1 mg/ml), sennosides (40 mg/ml), metronidazole (25 mg/ml), lidocaine (2.5 mg/ml), econazole (7.2 mg/ml), naproxen sodium (27.5 mg/ml), nonoxynol-9 (one condom/50 ml sterile water; used at 1:1 dilution), benzalkonium chloride (1 wipe/100 ml sterile water; used at 1:1 dilution).

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Clinical Studies

Reproducibility and OC

Reproducibility and Quality Control were performed during the clinical studies. Quality Control and Reproducibility strains were subcultured to BAP each day of testing and observed for growth to ensure purity and the viability of the organism.

Reproducibility of the chromID® Strepto B agar was evaluated with 11 organisms including one non-hemolytic strain of Streptococcus agalactiae, and one Staphylococcus aureus strain. These organisms were tested at three of the trial sites. Expected results were obtained 100% of the 990 times tested.

Quality Control was performed with two quality control organisms tested at each study site by chromID Strepto B agar on each day of comparative and reproducibility testing:

Streptococcus agalactiae ATCC 12386, positive control

Staphylococcus aureus ATCC 6538 negative control

The results for chromID Strepto B agar were 100% correct for the 107 times tested.

Prospective Clinical Study

Clinical studies were conducted at three external sites with fresh clinical specimens. These studies were designed to evaluate the recovery Streptococcus agalactiae from 18-24 hour LIM broth enrichments of vaginal/rectal swab specimens (from pregnant women) by chromID Strepto B agar. Positive results were defined for chromID Strepto B agar as the growth of pale pink to red colonies. No growth or colonies presenting as other than pale pink to red in appearance were interpreted as a negative result. All colony types growing on chromID Strepto B agar were characterized using one or more of the following laboratory tests: gram stain, catalase, PYR testing, and latex agglutination. In addition, VITEK® MS was used to identify all organisms growing on chromID® Strepto B agar. For the Reference Culture Method, turbid LIM broth cultures were subcultured to CNA agar, and all suspicious colonies were screened to confirm or rule-out the presence of GBS using established laboratory methods: gram stain, catalase, PYR testing, and latex agglutination. VITEK MS was also used to confirm the identification of GBS by the Reference Method. Negative broth enriched specimens were incubated an additional 24 hours before calling samples negative by the Reference Culture Method.

A total of 681 vaginal/rectal specimens enriched in LIM broth per CDC guidelines were analyzed during the clinical trial. There were 60 isolates and 5 cultures removed due to protocol deviations.

There were 172 cultures that were positive for Group B Streptococcus (GBS) by chromID Strepto B (24 hours) and by the Reference Culture Method.

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			Number Ntotal Performance	2-sided 95% ScoreCI
Sensitivity	172	176	97.7%	[94.3 - 99.1]%
Specificity	465	રે રેણવાડી તેમ જ દૂધની ડેરી જેવી સવલતો પ્રાપ્ય થયેલી છે. આ ગામનાં પ્રાથમિક શાળા, પંચાયતઘર, આંગણવાડી તેમ જ દૂધની ડેરી જેવી સવલતો પ્રાપ્ય થયેલી છે. આ ગામનાં પ્રાથમિક શાળા, આંગ	92.1%	[89.4 - 94.11%

chromID 24hr vs. Reference Culture Method

Comparison of chromID® Strepto B at 24 hours to the Reference Culture Method resulted in a Sensitivity of 97.7% (95% CI: 94.3% - 99.1%) and Specificity of 92.1% (95% CI: 89.4 % - 94.1%)

At 24 hours, a total of 212 cultures were positive by chromID Strepto B and 176 were positive by the Reference Method. Of the 40 false positive cultures, four cultures that were positive for GBS by chromID Strepto B agar were confirmed as GBS positive by characteristic color, Gram staining, catalase reaction, Lancefield Group B positive latex agglutination, and VITEK® MS identification. The remaining 36 false positives demonstrated pale pink to red colored colonies that were not confirmed as GBS.

In the chromID Strepto B clinical study, the prevalence of GBS detected by the Reference Culture Method was 25.8% (176/681).

The chromID Strepto B medium is a screening agar medium based on colony coloration, thus it further requires identification of pale pink to red Streptococcus agalactiae colonies using a laboratory approved procedure. The medium also has the ability to recover both hemolytic and non-hemolytic strains of Streptococcus agalactiae. The clinical trial has shown chromID Strepto B agar to be a safe and effective when used in the clinical setting.

Conclusion

The analytical and clinical data demonstrate that chromID® Strepto B medium is substantially equivalent to the predicate device.

Regulation Number and Section

§ 866.2360 Selective culture medium.

(a)
Identification. A selective culture medium is a device that consists primarily of liquid or solid biological materials intended for medical purposes to cultivate and identify certain pathogenic microorganisms. The device contains one or more components that suppress the growth of certain microorganisms while either promoting or not affecting the growth of other microorganisms. The device aids in the diagnosis of disease caused by pathogenic microorganisms and also provides epidemiological information on these diseases.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 866.9.