Friis Solid Medium Base

Intended Use

Recommended for the detection of non-avian Mycoplasmas in pharmaceutical products in accordance with European pharmacopoeia.

Composition**

Final pH (at 25°C): 7.40 - 7.45

**Formula adjusted, standardized to suit performance parameters

* - Equivalent to Calf brain infusion

# - Equivalent to Beef heart infusion

Directions

Suspend 62.28 grams (the equivalent weight of dehydrated medium) in 820 ml purified / distilled water. Heat to boiling to dissolve the medium completely. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes. Cool to 45-50°C. Aseptically add 90 ml of Horse serum (RM1239), 90 ml of Swine serum (RM10415) and rehydrated contents of one vial of Friss Selective supplement (FD317). Mix well and dispense as desired.

Principle And Interpretation

Mycoplasmas (mollicutes) are the smallest free-living microorganisms (5). Earlier Mycoplasmataceae were given the general title of pleuropneumonia like organism (PPLO), because of similarities to Mycoplasma mycoides (subsp. mycoides), the causative agent of bovine pleuropneumonia (1). Although some species are normal human respiratory tract flora, Mycoplasma pneumoniae is an important cause of pneumonia and a major cause of respiratory disease. Mycoplasma hominis, Mycoplasma genitalium and Ureaplasma urealyticum are important colonizers (and possible pathogens) of the human genital tract.

This medium is recommended by European pharmacopoeia (2) for the detection of non-avian mycoplasma. The optimum growth conditions are 35-38°C under microaerophilic conditions.

For the cultivation of Mycoplasma the medium ingredients and all the supplements should be free of any toxic substances even in small amounts. Proteose peptone, peptone, yeast extract, HM infusion and HM Infusion B provide nitrogen, vitamins, amino acids and carbon sources. Sodium chloride maintains the osmotic balance. Many Mycoplasma require serum which is supplemented by horse serum and swine serum in the medium for their good growth. The presence of antibiotic is necessary to prevent the growth of contaminating organisms. Mostly the Mycoplasma species are aerobic or facultatively anaerobic but some are microaerophilic. Sodium chloride maintains the osmotic balance. Phosphates buffer the medium. Other inorganic salts supply the necessary ions. DEAE-Dextran enhances the growth of some Mycoplasma species on Agar medium (6).

Type of specimen

Pharmaceutical samples

Specimen Collection and Handling

For pharmaceuticals samples follow appropriate techniques for handling specimens as per established guidelines (2). After use, contaminated materials must be sterilized by autoclaving before discarding.

Warning and Precautions

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 specimens. Safety guidelines may be referred in individual safety data sheets.

Limitations

1. Further biochemical tests should be carried out for confirmation.

Performance and Evaluation

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

Quality Control

Appearance Light yellow to pink homogeneous free flowing powder

Gelling Semisolid to slightly firm gel comparable to 0.85% Agar gel

Colour and Clarity of prepared medium Light pink coloured clear to slightly opalescent gel forms in tubes.

pH 7.40-7.45

Cultural Response Cultural response observed after addition of 90 ml of Horse serum (RM1239) , 90 ml of Swine serum (RM10145) and rehydrated contents of one vial of Friss Selective Supplement (FD317) after an incubation at 35-38°C for 48 hours to one week under microaerophilic condition.

Storage and Shelf Life

Store between 10-30°C in a tightly closed container and the prepared medium at 2-8°C. Use before expiry date on the label. On opening, product should be properly stored dry, after tightly capping the bottle in order 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 sample must be decontaminated and disposed of in accordance with current laboratory techniques (3,4).

Reference

1. Collee J.G, Fraser A.G., Marmion B.P., Simmons. A (Eds.), 1996, Mackie and McCartney Practical Medical Microbiology, 14th Ed, Churchill Livingstone.
2. European Pharmacopoeia, 2016, European Dept. for the quality of Medicines.
3. Isenberg, H.D. Clinical Microbiology Procedures Handbook 2nd Edition.
4. 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.
5. Murray P.R., Baron E. J., Pfaller M.A., Tenover F.C., Yolken R.H.(Eds.),1995, Manual of Clinical Microbiology, 6th Ed., ASM Press.
6. Tauraso, Nicola M., 1967: Effect of diethylaminoethyl dextran on the growth of Mycoplasma in agar. J Bacteriol: 1559-1564.