Header Ads Widget

SOP for Growth Promotion & Inhibition Test Procedure of Microbial Media

OBJECTIVE
To lay down a procedure for evaluating the growth promotion and inhibition properties of media used for Microbiological testing.

SCOPE
This procedure is applicable to all media which is used for microbiological testing in the Microbiology laboratory at PharmaSky Limited.

RESPONSIBILITY
Microbiologist – Responsible for execution of activity.
Section In-Charge – Responsible for review the procedure.
QC Head – Responsible for implementing the Procedure.
QA Head – Overall compliance.

PROCEDURE
  • Each lot of media is received to be tested for its growth promotion and inhibition qualities.
  • Growth Promotion Test shall be performed for one container of each lot.
  • Prepare required quantity of media for growth promotion test as per as per SOP for Growth Promotion Test.
  • For daily prepared media GPT shall be performed as a positive control test with the respective microorganisms mentioned in table – 1.
  • Prepare culture suspension as per current version of SOP for Preparation of Culture Media and select the dilution which gives 10-100 cfu/mL for growth promotion test.


Test for Growth Promotion properties of liquid media (Broth):
  • Prepare the required quantity of media to be tested and distributed in flasks or tubes and sterilized as per current version of SOP for Preparation and Sterilization of Microbial Media or as per manufacturer’s instructions.
  • Transfer the sterile tubes/flasks containing media to LAF bench and allow it to cool to room temperature.
  • Record the following details on the conical flasks /tubes.
  1. Name of the Media:
  2. Lot No. of Medium:
  3. Organism being used for growth promotion:
  4. Tested by / date:
  • Inoculate 1.0 mL of culture suspension having 10-100 cfu/mL into tube/flask containing sterile liquid media or broth (test sample).
  • Incubate the tubes/flasks as per the conditions mentioned in Table – 1.
  • Negative control should be kept along with the test samples without adding culture suspension.
  • After specified incubation period, observe the tube/flask and record the observations in Annexure I.

Acceptance criteria:
  • Growth/ turbidity shall be observed in test sample.
  • Growth/turbidity shall not be observed in negative control.

Test for Growth Inhibition properties of liquid media (Broth):
  • Transfer the sterile tubes/flasks containing media to micro LAF bench and allow it to cool to room temperature.
  • Record the following details on the conical flasks /tubes.
  1. Name of the Media:
  2. Lot No. Of Medium:
  3. Organism being used for growth inhibition:
  4. Tested by / date:
Inoculate 1.0 mL of culture suspension having 10-100 cfu/mL into tube/flask containing sterile liquid media or broth (test sample).
Incubate the tubes/flasks as per the conditions mentioned in Table – 1.
Negative control should be kept along with the test samples without adding culture suspension.
After specified incubation period, observe the tubes/flasks and record the observations in Annexure - I.

Acceptance criteria:
  • Growth/turbidity should not be observed in test sample and in negative control.


Test for Growth Promotion and Indicative Properties of solid media:
  • Transfer the sterile media, sterile petriplates to micro LAF bench.
  • Record the following details on the bottom of the Petri plate.
  1. Name of the Media:
  2. Lot No. of Media:
  3. Organism being used for growth promotion:
  4. Tested by / date:
  • Transfer 1.0 mL of culture suspension having 10-100 cfu/mL into two sterile Petri plates and aseptically pour the 15-20 mL of test sample at 40 to 45 °C into the plates.
  • Incubate the plates as per the conditions mentioned in Table – I.
  • Negative control should be kept along with the test samples without culture suspension.
  • After specified incubation period, observe the plates for growth and count the colonies obtained in each plate and record the results in Annexure-II.
  • The average of the colonies obtained in duplicate plates is used in the calculation of microbial recovery.

Acceptance Criteria:
  • The recovery of microbial cells must not differ by a factor greater than 2 from the calculated value for a standardized inoculum.
  • The colonies are comparable in appearance and indication reactions to those previously obtained with a previously tested and approved batch of medium.
  • No growth should be observed in negative control.

Test for Growth Inhibitory properties of solid media:
  • Transfer the sterile media, Petriplates to micro LAF bench.
  • Record the following on the bottom plate.
  1. Name of the Media:
  2. Lot No. of Media:
  3. Organism being used for inhibition:
  4. Tested by / date:
  • Transfer 1.0 mL of culture suspension having 10-100 cfu/mL into two sterile petriplates and aseptically pour the 15-20 mL of test sample at 40°C to 45°C into the petriplates.
  • Incubate the plates as per the conditions mentioned in Table – I.
  • Negative control should be kept along with the test samples without adding culture suspension.
  • After specified incubation period, observe the plates for growth and count the colonies, if any, obtained in each plate and record the results in Annexure-II.

Acceptance criteria:
  • Growth should not be observed in test sample and in negative control.


  • Growth indicative properties shall be performed for the selective media as mentioned in Table –I and record the observations in Annexure II.
  • GPT passed media shall be used for routine microbial analysis.
  • In case the media fails in the growth promotion test then reject the media.

Precautions:
  • Media should be stored at 10°C to 30°C or as per instructions given by manufacturer.
  • Check the physical condition of dehydrated media powder, if lumps are formed in the media discard that media.
  • Prepare & sterilize all the media as per manufacturer’s instructions.
  • Care should be taken while handling the cultures.




* Growth Inhibition Tests shall be performed.
# Growth indicative properties shall be formed.

ABBREVIATIONS
QC: Quality Control
QA: Quality Assurance
SOP: Standard Operating Procedure
LAF: Laminar Air Flow
GPT: Growth Promotion Test
cfu: Colony Forming Units
NMT: Not more than
NLT: Not less than

REVISION HISTORY
Nil

Post a Comment

0 Comments

close