BSK - H Medium Base

Intended use

For the cultivation of Borrelia burgdorferi.

Composition**

Final pH ( at 25°C): 7.6±0.2

**Formula adjusted, standardized to suit performance parameters

$- Equivalent to Bovine Serum Albumin

Directions

Suspend 25.0 grams of Part A in 450 ml distilled water. Mix well to dissolve the medium completely. To this add 15.9 grams of the medium. Add distilled water to make the final volume to 500 ml. Mix thoroughly to get a clear solution. Sterilize by filtration. DO NOT AUTOCLAVE. Aseptically add entire contents of one vial of APR Selective Supplement (FD179) and 30 ml of BSK-H Supplement (FD180). Mix well and dispense as desired.

Principle And Interpretation

BSK-H Medium is a modification of BSK-II medium developed by Pollack et al. (1) for the cultivation of Borrelia burgdorferi. Borrelia species are relatively slow-growing and their nutritional requirements appear to be complex. The study of Borrelia was greatly facilitated by the development of a culture medium by Kelly (2) that supported the growth of Spirochaetes. Stoenner enriched the basic formulation of Kelly with the addition of yeast extract tissue culture medium (3). Subsequent modifications by Barbour (4) resulted in BSK (Barbour-Stoenner-Kelly) medium, which facilitated isolation of Borrelia form a variety of tissue. This medium is complex mixture of different amino acids, vitamins and growth factors which are required for the growth of Borrelia and Spirochaete, it is enriched with bovine albumin and rabbit serum. Peptone, special serves as nitrogen source while glucose as energy source. Cholesterol incorporated in the medium acts as source of lipid. The success of in vitro culture of Borrelia is usually dependent on the quality of the animal serum or albumin used in media preparation (5). HEPES provides buffering capacity to the medium while different salts of Magnesium, sodium, calcium and potassium maintain the ionic balance in the medium.

Type of specimen

Clinical samples -skin scrappings, urine samples, etc

Specimen Collection and Handling

For clinical samples follow appropriate techniques for handling specimens as per established guidelines (6,7). After use, contaminated materials must be sterilized by autoclaving before discarding.

Warning and Precautions

In Vitro diagnostic Use only. For professional use only. Read the label before opening the container. Wear protective gloves/protective clothing/eye protection / face protection. Follow good microbiological lab practices while handling specimens and culture. Standard precautions as per established guidelines should be followed while handling clinical specimens. Safety guidelines may be referred in individual safety data sheets.

Limitations

1. Since the medium is nutritionally rich, it is more likely to get contaminated.
2. Proper filter sterilization should be carried out
3. Medium contains heat sensitive components, hence should not be boiled or heated.
4. Further isolation and biochemical tests must be performed for confirmation.

Performance and Evaluation

Performance of the medium is expected when used as per the direction on the label within the when stored at recommended temperature.

Quality Control

Appearance Light yellow to pink homogeneous free flowing powder

Colour and Clarity of prepared medium Light orange coloured, clear transparent liquid forms in tubes.

Reaction Reaction of 3.18% w/v aqueous solution of the medium along with Bovine Serum albumin at 25°C. pH : 7.6±0.2

pH 7.40-7.80

Microbial Load Maximum Limit

Cultural Response M1668: Cultural characteristics observed after 1-4 weeks incubation at 30-35°C after addition of APR Selective Supplement (FD179) and of BSK-H Supplement (FD180).

Key : *Corresponding WDCM numbers.

Storage and Shelf Life

Store at 2 - 8°C in tightly closed container. Use before expiry date on the label. On opening, product should be properly stored dry, after tightly capping the bottle inorder to prevent lump formation due to the hygroscopic nature of the product. Improper storage of the product may lead to lump formation. Store in dry ventilated area protected from extremes of temperature and sources of ignition Seal the container tightly after use. Product performance is best if used within stated expiry period.

Disposal

User must ensure safe disposal by autoclaving and/or incineration of used or unusable preparations of this product. Follow established laboratory procedures in disposing of infectious materials and material that comes into contact with clinical sample must be decontaminated and disposed of in accordance with current laboratory techniques (6,7).

Reference

1. Pollack R.J. et al, 1993, J. Clin. Microbiol., 31:1251-5.
2. Kelly, R., 1971, Science, 173:443-444.
3. Stoenner, H.G. et al, 1982, J. Exp. Med., 156:1297-1311.
4. Barbour, A.G., 1984, J. Biol. Med. , 57:521-525.
5. Calister, S.M, et al., 1990, J. Clin. Microbiol., 28:363-365.
6. Isenberg, H.D. Clinical Microbiology Procedures Handbook. 2nd Edition.
7. Jorgensen, J.H., Pfaller, M.A., Carroll, K.C., Funke, G., Landry, M.L., Richter, S.S and Warnock., D.W. (2015).Manual of Clinical Microbiology, 11th Edition. Vol. 1.