(365 days)
The BACTEC® MYCO/F Lytic culture vials when used with the 9000 Blood Culture series of instrumentation are intended as an adjunct to routine blood culture for patients suspected of having mycobacteria, yeast and fungi septicemia. Extended incubation times (7 days for yeast, 30 days for fungi, and 42 days for mycobacteria) will permit recovery of mycobacteria and fungi when more rapidly growing organisms are not present. This medium may also be used for the culture of sterile body fluids when yeast or fungi are suspected.
BACTEC MYCO/F LYTIC Culture medium is a Middlebrook 7H9 and Brain Heart Infusion broth formulation for the recovery of mycobacteria from blood specimens and fungi from blood and sterile body fluids. The range of specimen volume which can be cultured is one to five mL. with optimum recovery obtained at three to five mL. Specific modifications were made to enhance the growth and recovery of mycobacteria, veast, and fungi. These modifications include ferric ammonium citrate to provide an iron source for specific strains of mycobacteria and fungi, the addition of saponin as a blood lysing agent and the addition of specific proteins and sugars to provide nutritional supplements. Each vial contains a sensor which can detect decreases in oxygen concentration in the vial resulting from microorganism and growth. The sensor is monitored by the BACTEC 9000 Blood Culture Systems for increasing fluorescence which is proportional to the decrease in oxygen. A positive determination indicates the presumptive presence of viable microorganisms in the vial.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
Acceptance Criteria and Device Performance
The BACTEC MYCO/F LYTIC Blood Culture Medium is deemed substantially equivalent to predicate devices (BACTEC 13A for mycobacteria and BACTEC NR FUNGAL for yeast/fungi) based on internal and clinical studies demonstrating "equivalent performance." While explicit numerical acceptance criteria for recovery rates or time to detection are not provided as fixed thresholds, the studies aim to show that the new device performs comparably or better than the predicate devices across various clinically relevant scenarios.
Table of Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria (Implied by Substantial Equivalence Goal) | Reported Device Performance (BACTEC MYCO/F LYTIC) | Predicate Device Performance (BACTEC 13A / BACTEC NR FUNGAL) | Notes |
|---|---|---|---|---|
| Recovery of Mycobacteria (Clinical) | Equivalent or improved recovery compared to BACTEC 13A. | 10 (9%) isolates recovered only by Myco/F Lytic. | 3 (3%) isolates recovered only by BACTEC 13A. | Myco/F Lytic demonstrated improved unique recovery for mycobacteria. Total 111 pathogenic mycobacteria isolates. |
| Recovery of Yeast & Fungi (Clinical) | Equivalent or improved recovery compared to ISOLATOR™ System. | 7 (22%) isolates recovered only by Myco/F Lytic. | 6 (19%) isolates recovered only by ISOLATOR™ System. | Myco/F Lytic demonstrated slightly improved unique recovery for yeast/fungi. Total 32 pathogenic yeast/fungal isolates. |
| Recovery of Yeast & Fungi (Internal) | Equivalent recovery and time to detection (TTD) compared to BACTEC NR FUNGAL. | Improved recovery of Histoplasma capsulatum and Malesezzia furfur. Equivalent for various Candida and Cryptococcus species. Not detectable for Penicillium purpurescens and Blastomyces dermatitidis. Inconsistent for Hansenula anomala, Exophiala jeanseimelei, Actinomyces bovis, Rhodotorula rubra, Mucor ramosissimus at low inoculum. | (See Table 2 for detailed TTD) | Mixed results depending on the specific organism and inoculum level. The phrase "equivalent performance" might be an overarching claim, with noted exceptions. |
| Recovery of Mycobacteria (Internal) | Acceptable recovery and TTD compared to BACTEC 13A (implicitly). | Acceptable for a majority of tested species. Detection delays/compromised recovery for M. intracellulare, M. malmoense, M. haemophilum, M. xenopi with |
§ 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.