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I. Principle: | II. Protocol:


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Quality Control, Microbiology

I. Principle:

Quality Control provides a means of detecting variance from expected analytical behavior and, if variance is detected, furnishes a straightforward framework or clear path of action, which will:
enable Testing Personnel to determine if corrective action, either immediate or deferred, is warranted,
provide supporting documentation which will lend direction in terms of problem-solving if required and,
neither delay the release of clinically correct results nor allow the release of clinically erroneous results.

II. Protocol:

1. Equipment Monitoring:

A. Incubator:
Record the temperature of the incubator daily on the Incubator Temperature Log as outlined in the “
Temperature Monitoring” protocol in the Quality Assurance Manual. The acceptable temperature range is 33 - 37°C. When the temperature exceeds the posted limits, complete an IPR and contact the Supervisor or an Instrument Specialist.

B. Refrigerator:

a. Record the temperature of the refrigerator daily on the Temperature Recording Log, as outlined in the “Temperature Monitoring” protocol in the Quality Assurance Manual. The acceptable temperature range is 2 - 8°C. When the temperature exceeds the posted limits complete an IPR and contact the Supervisor or an Instrument Specialist. If the upper limit is exceeded, the media can be stored at room temperature for 36 – 48 hours. If the lower limit is exceeded, check to see if the media is frozen. Discard any media that appears to have been frozen.

b. Clean the refrigerators as needed, determined by visual inspection or at least every six months and document.

C. Gas Pak Anaerobe Jars:

a. Place a Methylene blue indicator in each jar every time it is used. Record the results of this indicator daily on the Microbiology Q.C. Log. Check the “Blue” column if the indicator does not function properly and the “White” column if it does function properly.

b. Pair each numbered or named jar and lid together when a jar is used.

c. Visually inspect any jar that fails to function properly. Check for cracks in the jar lid, etc.

d. Check the stock (N) media jar for pre-reducing anaerobic media daily. Record results of the indicator check on the Microbiology Q.C. Log as outlined in II.1.C.a. of this procedure. Once a week, open the jar, wipe it out with 1:10 bleach, check the media for possible fungal contamination and re-close. Document this action on the Microbiology Q.C. Log. Handle any malfunctions of this jar as outlined above.

e. The following maintenance steps are done on all Gas Pak Jars three times per year. Document this action on the Microbiology Q.C. Log.

1. Clean the jars and lids with a mild soap solution.

2. Check the condition of the O-ring gasket in the lids. Examine for cracks, bumps, dirt and improper seating in the O-ring groove. Examine the O-ring groove wall for splitting or cracking. The O-ring must be resilient, clean, and snugly retained within the O-ring groove for satisfactory operation of the system. Replace as necessary.

3. Inspect all plastic lids and clamps for cracks, bumps, split O-ring grooves and other irregularities. Most cracks (craze or stress lines) develop after prolonged use or excessive tightening of clamps on lids. Early cracks may appear as fine black lines near the center of the lid or along the upper edges of the clamp near the screw. A cracked lid and clamps exhibiting these fine black lines should not be used.

4. Inspect all jars for cracks and other irregularities. Replace as necessary.

D. Candle Jars (CO2):

a. Three times per year, wipe out the CO2 jar with 1:10 bleach to remove soot and dirt. Document this action on the Microbiology Q.C. Log.

b. Do not use scented or colored candles because they may inhibit bacterial growth.

E. Micro Coolers:
Three times per year, wipe out the coolers with 1:10 bleach to remove any dirt. Document this action on the
Microbiology Q.C. Log.

2. Media:
Obtain media from UCL Microbiology Dept. at Cathedral Square.

A. Store the stock media in the refrigerator. The bags are labeled with the type of media, lot number and expiration date.

B. When stock media is placed in the refrigerator, check the expiration date on the bag to verify it is not expired. Rotate the media so those with the shortest outdates are placed in the front and will be used first. Discard all outdated media.

C. Keep “in use” media on the Microbiology counter.

D. When “in use” media is restocked put the new media on the bottom so the older media is used first.

3. Supplies and Reagents:
All supplies and reagents are labeled as to contents, concentration, date prepared or received and/or lot number, date placed in service and date of expiration or shelf life. Refer to the “
Labeling & Dating of Chemical & Biological Reagents” procedure.

4. Growth Controls:

A. Inoculate the following plates daily with the appropriate organisms from the previous days Q.C. plates. Plates and organisms used include:

a. Blood Agar plate (BA) – S. pneumoniae

b. Chocolate Agar plate (CA) – H. influenzae, N. gonorrhoeae.

c. Chocolate Agar (CA)/Thayer Martin (TM) bi plate – N. gonorrhoeae, H. influenzae, Coagulase negative Staphylococcus.

B. Quality Control plates are handled in the following manner:

a. Place a Taxos P disk on the BA plate on the area of the second streaking. Place the BA with S. pneumoniae in the incubator. DO NOT place in the CO2 jar.

b. Inoculate half of the CA plate with H. influenzae and place a Bacitracin disk on the plate. Inoculate the other half of the CA plate with N. gonorrhoeae.

c. Inoculate one half of both sides of the CA/TM bi-plate with N. gonorrhoeae. Inoculate the other half of the TM side with Coagulase negative Staphylococcus. Inoculate the other half of the CA side with H. influenzae.

d. Place the CA whole plate with H. influenzae and N. gonorrhoeae and the CA/TM bi-plate with N. gonorrhoeae, Coagulase negative Staphylococcus and H. influenzae in the candle jar.

e. Record the lot number and expiration date of each plate inoculated on the Growth Controls Card. Date and initial the card.

C. Send the Q.C. plates and Growth Controls Card from the previous day to UCL Microbiology for the Quality Control to be read and results recorded on the Growth Controls Card.

D. The results are read and recorded by Microbiology, Cathedral Square staff. The Growth Controls Card is returned to the appropriate hospital site.

E. Expected Quality Growth Controls Card Results:

a. Blood Agar plate (BA) – S. pneumoniae:
Substantial growth with inhibition of 14 mm or greater around the Taxos P disk on the BA plate is acceptable. UCL Microbiology Dept staff record growth or no growth and measure and record the zone of inhibition daily on the
Growth Controls Card.

b. Chocolate Agar plate (CA) – H. influenza: The organism should grow up to the Bacitracin disk. UCL Microbiology Dept staff record growth or no growth and measure and record the zone of inhibition daily on the Growth Controls Card.
N. gonorrhoeae: The organism grows on the CAP. UCL Microbiology staff record the growth or no growth daily on the
Growth Controls Card.

c. Chocolate Agar (CA)/Thayer Martin (TM) bi plate – N. gonorrhoeae demonstrates substantial growth on both the CA and TM sides of the bi-plate. Coagulase negative Staphylococcus show inhibited growth on the TM plate. H. influenzae grows on the CA side of the bi-plate. Microbiology staff record daily growth, no growth or inhibited growth on the Growth Controls Card.

F. The hospital site laboratory staff is responsible for checking the Growth Controls Card results and taking corrective action. Criteria outlined in E.a-c above is not met when UCL Microbiology staff record a Q.C. growth result, it should be brought to the immediate attention of the Site Supervisor and recorded in the Microbiology Incidence Log.

5. Gram Stain Quality Control:

A. Stain a quality control slide each time a new lot of reagent or a new kit is put into use and weekly thereafter. Record the results on the Gram Stain Set Quality Control Log. Refer to the “Gram Stain” procedure for further details. The positive side of the slide (Staphylococcus aureus) should stain the cocci deep purple and the negative side (E. coli or Pseudomonas aeruginosa) should stain the rods pink.

B. Unsatisfactory results must be reported immediately to the Supervisor. A fresh slide is stained immediately. If the fresh slide does not stain properly contact UCL Microbiology for suggestion on corrective actions.

C. Extra Gram Stain controls are kept in stock. Order slides from UCL Microbiology when the supply is low.

D. Keep all patient Gram Stain slides for one month.

6. Calibrated Loop Check:
Check the calibrated urine loop monthly as outlined in the Calibration Check of 0.001 ml “
Urine Loop Calibration” procedure. Document this action on the Urine Loop Calibration Log and the Microbiology QC Log.

 

i. August 1981 M. Roth, J. Hosch, J. Schaefer

ii. August 1992 S. Hosch (Revised: Micro Accession log added)

iii. February 1995 E. Steiner (Revised: II.4.B. added)

iv. December 2002 A. Hall (Revised: II.1.E. deleted)

 

Comprehensive Review:

Pathologist:

Technical Director:

 

Interim Review:

September 2009 S. Hosch (no changes)
August 2010 G. Miller (Revised: II.1.B.b., C.d., D.a., E., 3., 5.A., 6.)
October 2011 A. Johnson (Revised: II.4.E.b-c.)
March 2012 C. Pregler (Revised: II.1.A., 4.B.c-e., 4.E.a-c., 5.a.)

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