MB/BacT Process bottles are used with the MB/BacT Mycobacteria Detection System in qualitative procedures for recovery and detection of mycobacteria in clinical specimens other than blood.

Device Description

Automated system for growth and detection of mycobacteria organisms in clinical specimens other than blood.

AI/ML Overview

Here's a breakdown of the acceptance criteria and study information for the BacT/Alert MB/BacT Mycobacteria Detection System, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The provided text does not explicitly state formal "acceptance criteria" for performance metrics like sensitivity or specificity with predefined numerical thresholds. Instead, the study aims to demonstrate substantial equivalence by comparing the MB/BacT system's recovery rates and time to detection with predicate devices.

The "reported device performance" is presented through recovery rates for various mycobacteria species compared to the predicate devices.

Metric	Acceptance Criteria (Implicit)	Reported Device Performance (MB/BacT vs BACTEC)	Reported Device Performance (MB/BacT vs Solid Media)
Overall Mycobacteria Recovery	Comparable to predicate devices (BACTEC 460 and solid media)	MB/BacT recovered 151/179 isolates (84.4%) vs BACTEC 460 recovering 150/179 (83.8%)	MB/BacT recovered 335/395 isolates (84.8%) vs Solid Media recovering 307/395 (77.7%)
MB/BacT "Positives Only" (vs BACTEC)	Should show instances where MB/BacT detects growth that BACTEC 460 does not.	22 isolates unique to MB/BacT	Not applicable
BACTEC "Positives Only" (vs MB/BacT)	Should show instances where BACTEC 460 detects growth that MB/BacT does not.	18 isolates unique to BACTEC 460	Not applicable
Solid Media "Positives Only" (vs MB/BacT)	Should show instances where Solid Media detects growth that MB/BacT does not.	Not applicable	60 isolates unique to Solid Media
MB/BacT "Positives Only" (vs Solid Media)	Should show instances where MB/BacT detects growth that Solid Media does not.	Not applicable	88 isolates unique to MB/BacT
Time to Detection	Comparable to predicate devices.	Ranged from 7.9 to 17.1 days for MB/BacT (vs 5 to 14 days for BACTEC 460)	Not explicitly quantified for solid media in this summary.
Ability to Grow Mycobacteria Strains In Vitro	Must demonstrate support for growth of a variety of mycobacteria organisms.	Demonstrated growth of several ATCC strains and clinical strains from CDC.	Demonstrated.
Level of Growth to Trigger Positive Reading	Instrument capable of detecting growth at relevant concentrations.	Triggered positive reading at 10^0 to 10^6 CFU/ml.	Demonstrated.

Summary of Device Performance based on the Tables provided:

MB/BacT vs BACTEC 460: The overall recovery rates are very similar (MB/BacT: 151, BACTEC: 150). Both systems also detected isolates that the other did not (MB/BacT only: 22, BACTEC only: 18).
MB/BacT vs Solid Media: MB/BacT showed a higher overall recovery rate (335) compared to solid media (307). MB/BacT also uniquely identified more isolates (88) than solid media did uniquely (60).
Time to Detection: The time to detection for MB/BacT was slightly longer on average (7.9 to 17.1 days) compared to BACTEC 460 (5 to 14 days).

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

Test Set Sample Size:
- For the MB/BacT vs BACTEC comparison, the total number of unique mycobacteria isolates recovered across all methods was 179.
- For the MB/BacT vs Solid Media comparison, the total number of unique mycobacteria isolates recovered across all methods was 395.
- The total number of clinical specimens is not explicitly stated, only the number of isolates recovered.
Data Provenance: Clinical specimens were collected from 4 clinical sites. The country of origin is not specified, but given the context of a US FDA 510(k) submission, it is highly likely to be United States data. The data is prospective, as it involved direct comparison studies conducted at clinical sites.

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 qualifications for establishing ground truth. However, the ground truth for identifying "mycobacteria species" and "total recovered" would have been established by standard microbiology laboratory procedures at the four clinical sites, likely by trained microbiologists using recognized culture and identification methods.

4. Adjudication Method for the Test Set

The document does not describe an adjudication method. The comparison tables present aggregated results for organisms recovered by each method, implying that if an organism was recovered by any of the methods, it was considered a "total recovered" isolate. This suggests a "Union" approach where any positive result from a validated method contributes to the ground truth of presence, rather than a specific adjudication process between conflicting results.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No, an MRMC comparative effectiveness study was not done. This device is an automated system for detecting microbial growth, not an imaging diagnostic requiring human interpretation. The study compares the performance of the automated system to other laboratory methods (both manual and automated), not the performance of human readers with or without AI assistance.

6. Standalone Performance Study

Yes, a standalone study was done for the algorithm (device). The entire clinical study is a standalone performance evaluation of the MB/BacT system compared to predicate devices. The system operates independently to detect growth and provide a positive reading. The results in the tables reflect the performance of the MB/BacT system on its own.

7. Type of Ground Truth Used

The ground truth used was microbiological culture and identification. The "Total recovered" column in the tables represents the ground truth for the presence of mycobacteria, meaning that if a mycobacterium species was successfully isolated and identified by any of the comparative methods (MB/BacT, BACTEC 460, or solid media), it was counted as a recovered isolate. The specific type of mycobacteria (e.g., M. tuberculosis, M. avium) would be confirmed through further laboratory identification methods.

8. Sample Size for the Training Set

The document does not specify a separate "training set" sample size. This is typical for device submissions of this nature, especially in 1996, where the "training" (development and refinement) of the device's
detection algorithm would have involved various in-house studies (growth promotion, colony count determination) rather than a distinct, prospectively collected clinical "training set" dataset as understood in modern AI/ML contexts. The "ATCC strains were used and clinical strains not commonly encountered were obtained from CDC for testing" for growth promotion studies, which could be considered part of the development/training process.

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

For the "growth promotion studies" which served a similar purpose to training:

For ATCC strains and CDC clinical strains: The ground truth for the presence and identity of these mycobacteria strains would have been established by standard microbiological techniques and culture verification methods inherent to their source (ATCC, CDC). This typically involves culturing, microscopy, biochemical tests, and potentially molecular methods to confirm the species and viability of the organisms.
Colony counts: For determining the level of growth to trigger a positive reading (10^0 to 10^6 CFU/ml), the ground truth for CFU/ml would have been established by standard quantitative microbiology techniques, such as pour plating or spread plating dilutions of known bacterial suspensions.

Summary

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K954468

JUL 22 1996

510(k) Summary

BacT/Alert MB/BacT Mycobacteria Detection System

This summary of safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and the final rule under 21 CFR 807.92 published December 14, 1994.

The submitter's name, address, telephone number, a contact person, and the date (A)(1) the summary was prepared:

Submitter's Name: Organon Teknika Corporation

Submitter's Address: 100 Akzo Avenue, Durham, NC, 27712

Submitter's Telephone: (919) 620-2634

Submitter's Contact: Ann M. Quinn

Date 510(k) Summary Prepared: July 11, 1996

(a)(2) The name of the device, including the trade or proprietary name if applicable, the common or usual name, and the classification name, if known.

Trade or Proprietary Name: MB/BacT Mycobacteria Detection System

Common or Usual Name: Microbial Growth Monitor

Classification Name: Microbial Growth Monitor

(a)(3) An identification of the legally marketed device to which the submitter claims substantial equivalence.

Device Equivalent to: Manual Methods including Lowenstein Jensen (LJ) slants, Middlebrook 7H11 solid media and Bactec 460, all of which are pre amendment devices.

(a)(4) A description of the device

Device description: Automated system for growth and detection of mycobacteria organisms in clinical specimens other than blood.

(a)(5) A statement of the intended use of the device

Device Intended Use: MB/BacT Process bottles are used with the MB/BacT Mycobacteria Detection System in qualitative procedures for recovery and detection of mycobacteria in clinical specimens other than blood.

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(a)(6) A summary of the technological characteristics of the new device in comparison to those of the predicate device.

MB/BacT Mycobacteria Detection System detects the growth of mycobacteria in a broth culture bottle by colorimetric measurement of CO2 production. Bactec 460 detects the orowth of mycobacteria in a broth culture bottle by radiometric measurement of CO2 production. Manual solid media methods such as Lowenstein Jensen slants or Middlebrook 7H11 plates, growth is detected by visual examination. MB/BacT cultures are continuously monitored while the other methods are monitored periodically. MB/BacT is a closed monitoring system once the specimen is inoculated into the bottle. This limits the technologist's exposure to potentially infectious organisms. This safety feature is not present in the other systems.

(b)(1) A brief discussion of the nonclinical tests submitted, reference, or relied on in the premarket notification submission for a determination of substantial equivalency.

Growth promotion studies were performed on the MB/BacT Process System which consists of the media bottle, antibiotic supplement, and reconstitution fluid along with the MB/BacT instrument. These data were generated to demonstrate that the media was capable of growing several strains of mycobacteria in vitro. ATCC strains were used and clinical strains not commonly encountered were obtained from CDC for testing. These data demonstrate the MB/BacT Process System is capable of supporting growth of a variety of mycobacteria organisms. Colony counts were performed on select strains to determination the level of growth to trigger a positive reading by the instrument. These counts ranged from 100 to 10° CFU/ml. Data was generated on select strains of mycobacteria at different concentrations comparing MB/BacT to Bactec 460. Times to detection ranged from 7.9 to 17.1 days for MB/BacT and from 5 to 14 days for Bactec 460 (when a G.I. of 50 was considered positive)

(b)(2) A brief discussion of the clinical tests submitted, referenced, or relied on in the premarket notification submission for a determination of substantial equivalency.

Comparison Studies were conducted at 4 clinical sites to evaluate the performance of the MB/BacT Mycobacteria Detection System compared to conventional solid media for growth and detection of mycobacteria. One of the sites also used the BACTEC 460 in addition to conventional solid media. The comparative methods used at the sites were as follows:

Site Comparative Method
Site A Lowenstein-Jensen Slants Middlebrook 7H11 bi-plates containing selective and non-selective media
Site B Lowenstein-Jensen Slants Middlebrook 7H11 selective agar slants
Site C Lowenstein-Jensen Slants Middlebrook 7H11 bi-plates containing selective and non-selective media

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Lowenstein-Jensen Slants Site D Middlebrook 7H11 bi-plates containing selective and non-selective media BACTEC 460 TB

Site E Lowenstein-Jensen Slants ВАСТЕС 460ТВ
A summary of the organisms recovered and comparison to the predicate devices is provided in the following tables.

Mycobacteria speciesonly	Totalrecovered	MB/BacTpos	MB/BacTpos only	Bactecpos	Bactecpos only	Solidpos
M. avium	67	52	4	61	10	43
M. chelonae	6	4	0	6	2	2
M. gordonae	21	17	14	7	2	3
M. intracellulare	1	1	0	0	0	1
M. kansasii	2	2	0	2	0	2
M. simiae	1	1	0	1	0	1
M. tuberculosis	79	74	4	71	2	65
M. xenopi	1	0	0	1	1	0
Atypical mycobacteria	1	0	0	1	1	0
Total isolates	179	151	22	150	18	117

Recovery of Mycobacteria species - MB/BacT vs BACTEC

Recovery of Mycobacteria species - MB/BacT vs Solid Media

Mycobacteria species	Totalrecovered	MB/BacTpos	MB/BacTpos only	Solidpos	Solidpos only
M. avium	132	111	38	94	21
M. chelonae	6	5	3	3	1
M. fortuitum	7	6	3	4	1
M. gordonae	31	30	24	7	1
M. kansasii	12	9	2	10	3
M. terrae	1	0	0	1	1
M. tuberculosis	205	173	18	187	32
M. xenopi	1	1	0	1	0
Total isolates	395	335	88	307	60

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The conclusions drawn from the nonclinical and clinical tests that demonstrate (b)(3) that the device is as safe, as effective, and performed as well or better than the legally marketed device identified in (a)(3).

The performance characteristics of the new device are comparable to those of the predicate devices and typical of methods used for detection of mycobacteria. The data presented in the premarket notification demonstrate that the new device performs substantially equivalent to the predicate devices.

Regulation Number and Section

§ 866.2560 Microbial growth monitor.

(a)
Identification. A microbial growth monitor is a device intended for medical purposes that measures the concentration of bacteria suspended in a liquid medium by measuring changes in light scattering properties, optical density, electrical impedance, or by making direct bacterial counts. The device aids in the diagnosis of disease caused by pathogenic microorganisms.(b)
Classification. Class I. With the exception of automated blood culturing system devices that are used in testing for bacteria, fungi, and other microorganisms in blood and other normally sterile body fluids, this device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter.