SOP for Growth Promotion Test

OBJECTIVE

To lay down a procedure to check the growth promotion properties of the procured media & also to describe the procedure to be followed to evidence each lot of prepared or autoclaved media supports the growth of microorganisms when all the environmental conditions for growth are provided.

SCOPE

The SOP applies to the media used for microbiological analysis in microbiology laboratories.

RESPONSIBILITY

Microbiologist: To perform the procedure as per SOP. 

Head – Quality Control: To ensure compliance with the SOP.

PROCEDURE

Liquid broth medium (Growth Promotion / Positive Control):

• Prepare culture dilution as per the Growth Promotion Test.
• Inoculate 1 ml of culture to the sterile culture media and incubate at the recommended temperature specified for the organism as per Table -1.
• The media complies with the growth promotion test if luxuriant growth (turbidity) is observed in the inoculated tubes of liquid media or distinct colony formation on the agar media within 48 hours of incubation.

• If the observations are without any microbial growth discard the batch of medium and reject an entire lot of media.
• Observe inoculated media & enter.

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Acceptance criteria:

• Micro-organisms must show turbidity in the inoculated broth media and distinct colony formation on the solid agar media within 48 hours duration.

Table- 1 (Routinely used media)

Culture Medium	Microorganism	Growth Temperature (°C)	Incubation Period (Hours)	Condition
Trypton Soya Broth or Soyabean Casein Digest Medium	Staphylococcus aureus Pseudomonas aeruginosa Bacillus subtilis	22.5 ± 2.5	24 - 72	Aerobic
Potato Dextrose Agar / Broth	Candida albicans	22.5 ± 2.5	24 - 48	Aerobic
Bismuth Sulphite Agar / Brilliant Green Agar/Xylose lysine deoxycholate agar	Salmonella abony	32.5 ± 2.5	24 - 48	Aerobic
Tetrathionate Brilliant Green bile broth/ Selenite broth	Salmonella abony	32.5 ± 2.5	24	Aerobic
Cetrimide Agar/ Pseudomonas Agar	Pseudomonas aeruginosa	32.5 ± 2.5	24 - 72	Aerobic
Baird-Parker Agar / Mannitol Salt Agar/ Vogal Jonson Agar	Staphylococcus aureus	32.5 ± 2.5	24 - 48	Aerobic
MacConkey Agar / Broth/EMB agar/Fluid lactose medium.	Escherichia coli ATCC	32.5 ± 2.5	24 - 48	Aerobic
Soyabean Casein Digest Agar	Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Aspergillus niger, Candida albicans	32.5± 2.5	24-72	Aerobic

• Any other selective/differential media, if required for microbiological testing, growth promotion tests to be performed with the microorganism specified by the manufacturer, mentioned on the label of the particular media container.

ANNEXURE

Nil

REVISION HISTORY

Nil

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