SOP for Sampling and testing for Surface Monitoring by Swab Sampling Method
1.0 Purpose:To lay down a standard operating procedure for surface monitoring by swab sampling method.
2.0 Scope:
This procedure is applicable for surface monitoring by swab sampling method in Microbiology Laboratory.
3.0 Responsibility:
Microbiologist / Designee:
* To perform sampling and testing of swab sampling as per frequency.
* To follow sampling procedure as per SOP.
* To analyze the sample as per testing procedure.
* To observe the plate as per incubation period.
* To fill the data as per format.
Head/ Designee - QC :
* To review, implement and ensure compliance of SOP.
Head/ Designee - QA:
* To approve, implement and ensure compliance of SOP.
4.0 Procedure:
4.1 Swab Sampling Procedure:
4.1.1 Enter in respective area as per the entry procedure.
4.1.2 Use ready to use swab e.g. Himedia PW003 is in sterile cotton swab screw capped polypropylene tube. Check the label of the box, quantity, lot number, code number, manufacturing date and check for the certificate of analysis.
4.1.3 Take entries in inward register as per A.R. number as EM/XXX/YY/ZZZZ
Where,
EM= Environment monitoring
XXX= SSW (Surface Swab Sampling)
YY= Current Calendar year
ZZZZ= Serial Number started from 0001, 0002, 0003 and so on.
4.1.4 Prepare the sterile normal saline or BSCP as per SOP of media preparation and sterilize in autoclave as per SOP of sterilization.
4.1.5 Transfer normal saline/ BSCP and required number of cotton swabs into LAF of Microbiology testing area through pass box.
4.1.6 Swab is removed from its protective packaging and dips into sterile saline and replaces back the swab in the tube.
4.1.7 The cotton swabs are now ready for surface monitoring.
4.1.8 These prepared swab tubes should be stored at 2-8°C and should be used within 24 hours.
4.1.9 Ensure that the surface is dry before taking the swab.
4.1.10 Cotton swabs must be handled carefully to avoid any contamination.
4.1.11 Before taking the swab, label on the polypropylene tube for name of swab of area under monitoring, date and sign.
4.1.12 Open the screw-capped tube.
4.1.13 If possible use the sterile 25cm2 template for the area to be monitored. The moistened cotton swab should be rolled in unidirectional (zigzag) on to the surface to be monitored taking care that the swab is touched to all over the surface (within 25 cm2).
4.1.14 Replace back the swab in tube. Disinfect the area with 70% IPA.
4.1.15 Bring the swab back to microbiology lab and store at 2-8°C till testing.
4.1.16 Analysed the swab samples as soon as possible.
4.2 Testing Procedure:
4.2.1 Label the sterile empty plate with the name of media, sterilization load no, location of sample, date and sign.
4.2.2 Add 10 ml sterile BSCP in to the tube. Vortex the tube, swirl and open the tube. Squeeze the swab bud on the wall of the tube.
4.2.3 Transfer the 1ml of sample from the container in presterilised plates. Plate must be handled carefully to avoid any contamination.
4.2.4 Use Soyabean Casein Digest Agar (SCDA). Prepared media as per SOP of media preparation and cooled up to 45- 50°C and Pour 15-20 ml the medium in petriplate and mix well. Allow to solidify.
4.2.5 Incubate plate at 20-25°C for 3 days (fungi) and 30-35°C for 2 days (Bacteria). Simultaneously also place one positive and negative control with test.
4.2.6 Count the number of colonies from each plate, and record the number of colonies as CFU/swab.
4.3 Limit:
Class Specified Limit (CFU/Swab) Fungi
A <1 Nil
B 5 Nil
C 25 Nil
D 50 Nil
4.4 Frequency:
4.4.1 Once in 3 month ±15 days.
5.0 Abbreviations:
QA-Quality Assurance
QC-Quality Control
°C-Degree Centigrade
CFU-Colony Forming Unit
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