TSA with Penase with Lecithin with Polisorbate

Description

This widely used culture medium contains soya and casein peptones in proven proportions to support the growth of most microorganisms, including some very fastidious ones. It has been formulated according to the harmonized method of pharmacopoeias and ISO standards and is regularly used in routine diagnostic work for its reliability in the morphological aspects and reproducibility of the results.

Penicillinase ensures the inactivation of penicillins or cephalosporins that may be present in the air or surfaces to be sampled, while the other neutralizers (TLHTh = Tween 80 - Lecithin - Histidine - sodium thiosulfate) do so with a variety of disinfectants and preservatives:

• Histidine neutralizes formaldehyde.
• Lecithin inactivates chlorhexidine.
• Sodium thiosulphate neutralizes halogenated compounds.
• Polysorbate (Tween) 80 inactivates hexachlorophene and mercury derivatives.
• The combination lecithin + polysorbate 80 neutralizes quaternary ammonium.
• The lecithin-polysorbate 80-histidine combination inactivates aldehydes and phenolic compounds.

Note: Contact plates are used for monitoring the microbiological contamination of surface and air inside cleanrooms, isolators, RABS, food industries and hospitals. The double/triple irradiated wrapping ensures that the package itself doesn't contaminate the environment as the first wrapper is removed just before entering the clean area.

Technique

In the microbiological control of cleaning and disinfection of surfaces in the "clean zones", the contact plates are used as a plug or copy-pad that acts simultaneously as a sampler and culture medium to be incubated, without other intermediate operations. For this, the 65 mm diameter plates are filled so that the medium forms a suitable meniscus to produce a contact surface of approximately 25 cm².

At the time of use, remove the outer shell of the plates, remove the cover of the plate and support the culture medium on the surface to be controlled, exerting a gentle pressure for about 10-15 seconds, to ensure good contact between the two surfaces. The plate is removed without rubbing and covered with its cover to avoid contamination. They are labeled appropriately with the sampling data (place, date and time) and are incubated. The inoculated plates are incubated at 30-35 °C for 24-72 h (bacteria) and 3-5 days for fungi (yeasts and molds). Examined daily.

When the effectiveness of a cleaning and/or disinfection process is verified, sampling with the contact plates should be done within two hours of the completion of the process, ensuring that the surfaces to be sampled are dry. Positive controls should always be included, sampling the area prior to disinfection or simultaneously monitoring unclean areas adjacent to the disinfected areas.

The frequency of cleaning/disinfection and subsequent sampling will be established by the responsible technician, depending on the results obtained and the proposed objectives.

Penicillinase to inactivate 10,000,000 IU PenG/L/min.

Physical/chemical control

Microbiological control

Control post addition of penicillin, according to harmonized pharmacopoeial monographs and test methods.

Aerobiosis. Incubation at 30-35 °C. Read after 18-24 h to 72 h for bacteria and 3-5 days for fungi.

Sterility control

Incubation 48 hours at 30-35 °C and 48 hours at 20-25 °C: NO GROWTH.

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• COLIPA (1997) Guidelines on Microbial Quality Management (MQM). Brussels.
• DOWNES, F.P. & K. ITO (2001) Compendium of Methods for the Microbiological Examination of Food, 4th ed, ASM, Washington D.C.
• EUROPEAN PHARMACOPOEIA 8.0 (2014) 8th ed. § 2.6.13. Microbiological examination of non-sterile products: Test for specified microorganisms. Harmonised Method. EDQM. Council of Europe. Strasbourg.
• FDA (Food and Drug Administration) (1998) Bacteriological Analytical Manual. 8th ed. Rev. A. AOAC International. Gaithersburg. MD.
• HORWITZ, W. (2000) Official Methods of Analysis of AOAC INTERNATIONAL, 17th ed. Gaithersburg, MD. USA.
• ISO 9308-1 Standard (2000) Water Quality. Detection and enumeration of E. coli and coliform bacteria. Membrane filtration method.
• ISO 11133:2014/Amd 1:2018. Microbiology of food, animal feed and water. Preparation, production, storage and performance testing of culture media.
• ISO 16212 Standard (2017) Cosmetics - Microbiology - Enumeration of yeast and mould.
• ISO 21149 Standard (2017) Cosmetics - Microbiology - Enumeration and detection of aerobic mesophilic bacteria.
• ISO 21150 Standard (2015) Cosmetics - Microbiology - Detection of Escherichia coli.
• ISO 22717 Standard (2015) Cosmetics - Microbiology - Detection of Pseudomonas aeruginosa.
• ISO 22718 Standard (2015) Cosmetics - Microbiology - Detection of Staphylococcus aureus.
• ISO/TS 22964 (2006) Milk and milk products - Detection of Enterobacter sakazakii.
• PASCUAL ANDERSON, Mª R. (1992) Microbiología Alimentaria. Díaz de Santos S.A., Madrid.
• USP 33 - NF 28 (2011) <62> Microbiological examination of non-sterile products: Test for specified microorganisms. Harmonised Method. USP Corp. Inc. Rockville. MD. USA.