SOP Title: Procedure for Surface Swab Analysis for Microbial Limits

SOP Title: Procedure for Surface Swab Analysis for Microbial Limits

1. Objective:

To lay down the Procedure for Surface Swab Sample Analysis for Microbial Limits.

2. Scope:

This Procedure is applicable for Surface Swab Sample Analysis for Microbial Limits.

 

3. Responsibility:

• Quality Control Department: To prepare and review the SOP. To follow the Procedure for        Surface Swab Sample Analysis for Microbial Limits as per this SOP.
• Quality Assurance Department: To review and approve the SOP and Annexure.

4. Accountability:

Head Quality Control Department, Head Quality Assurance department.

5. Procedure:

5.1	Safety Precautions:
5.1.1	Wear personal protective equipments such as protective hand gloves, nose masks and over gown during operation.
5.1.2	Microbiologist should disinfect the hand gloves with 70% v/v IPA before carrying out operation.
5.2	Methods for Swab Testing:
5.3	Surface Monitoring Using Swab
5.3.1	On receipt of intimation, Microbiologist should do necessary arrangement for collecting swab sample.
5.3.2	Prepare swab, solutions and Media as per Media Preparation and Sterilisation SOP .
5.3.3	To the location, carry sterile test tubes with cotton swabs containing 10 ml of sterile normal saline or Buffered Sodium Chloride Peptone Solution pH 7.0 to collect the swab sample as per define swabbing procedure.
5.3.4	Mark the with location, sample name and date of sampling.
5.3.5	With the help of sterile forceps remove swab and hold the end of the swab stick and take a sample of 10 x 10 cm2 area and dipped the swab stick back in 10 ml of same sterile normal saline/BSCP. Immediately close the test tube.
5.3.6	Bring all the test tubes in microbiology section and do the analysis by pour plate method.
5.3.7	Mix the sample and pipette out 1 ml of sample in 4 sterile petriplates.
5.3.8	In two plates, add 15 to 20 ml of sterile SCDA media previously cooled at 45°C mix slowly by rotating the plates and allow to solidify.
5.3.9	Incubate these plates at 30-35°C for 5 days for bacterial count along with negative control. i.e. plate out 1 ml of diluent in a single petriplate, and positive control i.e. plate out 1 ml of any positive culture (Bacterial), preferably S.aureus in single.
5.3.10	In other two plates add SCA/SDA media previously cooled at 45°C, mix slowly by rotating the plates and allow to solidify and then incubate the plates at 20-25°C for 5 days for fungal count along with negative control and positive control. Use Candida albicans as a positive control for fungi count.
5.3.11	Record the observations in Surface Swab Analysis record Annexure.
5.3.12	If the report are out of limits, intimate to Department Head and Quality Assurance Head, raise an incident and take further course of action.
5.3.13	If required, repeat the test one more time to confirm the result.
5.3.14	All equipments, petriplates and media are decontaminated as per SOP -Procedure for Destruction of Cultures and Microbial waste.
5.4	Procedure for Contact Plate:-
5.4.1	This Technique should be used for flat surfaces such a Working benches, walls and floors, Machine exterior surfaces etc.
5.4.2	Use Dey- Engley’s Agar Contact plate for carrying out this method. Refer SOP for media preparation.
5.4.3	Open the Pre prepared contact plate (from supplier) and gently press the convex surface on the area to be tested. Close the lid immediately. Label the plates appropriately. Single plate per area to be used for this test.
5.4.4	Immediately after sampling, clean the area of sampling thoroughly with 70% IPA or suitable disinfectant to prevent microbial growth on the surface.
5.4.5	After sampling, close each plate with the lid provided. Incubate at 20-250 C for first 3 days and 30-350 C for next two days for total bacterial and fungal count.
5.4.6	Record the count after completion of incubation period of 5 days.
5.4.7	Count the number of colonies on each plate and record the number of colonies as CFU/25 cm2 or CFU/Contact plate. Enter observations in Annexure.
5.5	Swab of Walls and Floors:-
5.5.1	Use Dey- Engley’s Agar Contact plate for carrying out this method. If  Pre prepared plates are not available prepare plates in the microbiology laboratory and use.
5.5.2	Open the Pre prepared contact plate (from supplier) and gently press the convex surface on the wall or floor to be tested. Close the lid immediately. Label the plates appropriately. Single plate per area to be used for this test.
5.5.3	Immediately after sampling, clean the area of sampling thoroughly with 70% IPA or suitable disinfectant to prevent microbial growth on the surface.
5.5.4	After sampling, close each plate with the lid provided. Incubate at 20-250 C for first 3 days and 30-350 C for next two days for total bacterial and fungal count.
5.5.5	Record the count after completion of incubation period of 5 days.
5.5.6	Count the number of colonies on each plate and record the number of colonies as CFU/25cm2 or CFU/Contact plate. Enter observations in Annexure.
5.5.7	If contact plates are not available, swab method can be used as an alternative method.
5.6	Hands Gloved Finger Dabs:-
5.6.1	Use Dey- Engley’s Agar Contact plate for carrying out this method.
5.6.2	Open the Pre prepared contact plate and gently press four gloved fingers one by one of one hand onto the surface of Dey Engley’s agar plates. Then take impression of thumb on same plate. Close the plate immediately. Repeat the same procedure for other hand. Use single plate for each hand.
5.6.3	The hand should not be disinfected prior to finger dab as to get a actual count during work.
5.6.4	After sampling, close each plate with the lid provided. Incubate at 20-250 C for first 3 days and 30-350 C for next two days for total bacterial and fungal count.
5.6.5	Record the count after completion of incubation period of 5 days.
5.6.6	Count the number of colonies on each plate and record the number of colonies as CFU/25cm2 or CFU/Contact plate. Enter observations in Annexure.
5.7	Monitoring of personnel gear:-
5.7.1	Before using any sterile overgown, check for any wear and tear, loose threads or any stains or other deformities.
5.7.2	Do not use such overgowns, replace them with a proper overgowns to avoid any contamination.
5.7.3	The Swab of personnel gear has to be taken at the end of the shift.
5.7.4	Use SCDA contact plates for carrying out this activity. Refer for media preparation SOP.
5.7.5	Open the Pre prepared contact plate and gently press against overgown.
5.7.6	Take swabs from from overgown i.e. Headgear, right forearm, left forearm, middle of the chest using 25cm2 contact plate.
5.7.7	After sampling, close each plate with the lid provided. Incubate at 20-250 C for first 3 days and 30-350 C for next two days for total bacterial and fungal counts.
5.7.8	Record the count after completion of incubation period of 5 days.
5.7.9	Count the number of colonies on each plate and record the number of colonies as CFU/25 cm2 or CFU/Contact plate. Record observations in Annexure.
5.7.10	Decontaminate all the plates and tubes after result recording by referring SOP, Decontamination of microbial culture media.
5.8	Testing Frequency:-
5.8.1	Surface Monitoring of equipments should be done as per the intimation received from other departments or for doing cleaning validation study.
5.8.2	Surface Monitoring of Walls and Floors should be done Monthly for Grade A areas and Microbiology Laboratory and Half Yearly for other areas.
5.8.3	Hand gloved Finger Dabs to be performed monthly and Monitoring of Over gown should be done Monthly.

 

6. Definitions/Abbreviations:

• Definitions :
• Abbreviations:

Abbreviation	Expansion
°C	Degree Centigrade
%	percentage

 

ml	millilitre
No.	Number
v/v	Volume by volume
SCDA	Soyabean Casein Digest Agar
IPA	Isopropyl Alcohol
cm2	Centimetre square
BSCP	Buffered Sodium Chloride Peptone solution pH 7.0

  

*Note – Ready to use SOP available in “DOWNLOAD” Section.