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BACTEC™ Myco/F Lytic culture medium when used with the BACTEC fluorescent series instruments is a nonselective culture medium to be used as an adjunct to aerobic blood culture media for the recovery of mycobacteria, yeast and fungi from blood. This medium may also be used for the culture of sterile body fluids when yeast or fungi are suspected.

Since the mid-1980s and expanding size of the immunocompromised patient population, the incidence of septicemia caused by opportunistic pathogens such as yeast, fungi and mycobacteria has risen. Mycobacterium tuberculosis (MTB) and mycobacteria other than tuberculosis (MOTT), especially Mycobacterium avium complex (MAC), have become resurgent. From 1985 to 1992, the number of MTB cases reported increased 18%. Between 1981 and 1987, AIDS case surveillances indicated that 5.5% of the patients with AIDS had disseminated nontuberculous mycobacterial infections, e.g., MAC. By 1990, the increased cases of disseminated nontuberculous mycobacterial infections had resulted in a cumulative incidence of 7.6%.¹ It has also been noted that the incidence of fungemia has steadily increased since the early 1980s. This has increased the need for the clinical laboratory to have effective diagnostic procedures for fungemia and mycobacteremia.

The Centers for Disease Control and Prevention (CDC) have recommended that every effort must be made for laboratories to use the most rapid methods available for diagnostic mycobacteria testing. These recommendations include the use of a liquid medium for mycobacterial culture.^2-4

The BACTEC fluorescent series instruments are designed for the rapid detection of microorganisms in clinical specimens. 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 yeast and fungi from blood and sterile body fluids. Specific modifications were made to enhance the growth and recovery of mycobacteria, yeast 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 metabolism and growth. The sensor is monitored by the BACTEC fluorescent series instrument for increasing fluorescence which is proportional to the decrease in oxygen. A positive determination indicates the presumptive presence of viable microorganisms in the vial.

Quality control requirements must be performed in accordance with applicable local, state and/or federal regulations or accreditation requirements and your laboratory's standard Quality Control procedures. It is recommended that the user refer to pertinent CLSI (formerly NCCLS) guidance and CLIA regulations for appropriate Quality Control practices.

It is recommended that each new shipment or lot of BACTEC Myco/F Lytic media be tested with the ATCC control organisms identified in the chart below as a positive control, and an uninoculated vial as a negative control.

The positive vials should be inoculated using a 1:100 dilution of a McFarland #1 suspension grown on solid medium. Inoculate the vial with 0.1 mL of the diluted culture. The vials and an uninoculated control vial should be scanned into the instrument and tested. The inoculated vial should be detected as positive by the instrument within the test protocol. The negative control should remain negative. If expected results for Quality Control are not obtained, do not use the medium and contact BD Technical Services (in the U.S only: 1-800-638-8663) or your local BD Representative for further assistance.

For information on quality control for the BACTEC System, refer to the appropriate BACTEC User's Manual.

Each BACTEC Myco/F Lytic culture vial contains the following active ingredients prior to processing:

This BACTEC medium is dispensed with added CO₂ and O₂.

BACTEC Myco/F Lytic medium requires no supplement addition. Each 40 mL vial of BACTEC Myco/F Lytic is ready for use when received. The appearance of the media upon receipt should be clear and light amber in color.

For in vitro Diagnostic Use.

This Product Contains Dry Natural Rubber.

Pathogenic microorganisms, including hepatitis viruses and Human Immunodeficiency Virus, may be present in clinical specimens. "Standard Precautions"^5-8 and institutional guidelines should be followed in handling all items contaminated with blood and other body fluids.

If recovery of mycobacteria is intended, CDC-NIH guidelines strongly recommend that the test instrument be placed in the mycobacteria laboratory where the additional safety issues that the recovery of mycobacteria present can be addressed.⁹

BACTEC Myco/F Lytic vials will accept more than the recommended maximum of 5 mL of specimen volume. Monitoring of fill should be conducted.

For activities involving the propagation and manipulation of Mycobacterium tuberculosis or Mycobacterium bovis grown in culture, Biosafety Level 3 practice, containment equipment and facilities are recommended.⁹

Prior to use, each vial should be examined for evidence of contamination such as cloudiness, bulging or depressed septum, or leakage. DO NOT USE any vial showing evidence of contamination, leakage or damage. Vial contamination may not be readily apparent. A contaminated vial could contain positive pressure. If a comtaminated vial is used for direct draw, gas or contaminated culture media could be refluxed into the patient's vein. On rare occasions, the glass bottle neck may be cracked and the neck may break during removal of the flip-off cap or in handling. Also, on rare occasions, a vial may not be sealed sufficiently. In both cases the contents of the vials may leak or spill, especially if the vial is inverted.

To minimize the potential of leakage during inoculation by syringe of specimen into culture vials, use syringes with Luer-Lok™ brand tips. A one-handed inoculation technique and a suitable vial holder should be employed to prevent accidental needle stick injury.

Before discarding, sterilize all inoculated BACTEC Myco/F Lytic vials by autoclaving.

Positive culture vials for subculturing or staining, etc.: Before sampling it is necessary to release gas which often builds up due to microbial metabolism. Sampling and venting of vials must be performed in a biological safety cabinet, and appropriate protective clothing, including gloves and masks, should be worn. See PROCEDURE Section for more information on subculturing.