APPLYING QUALITY ASSURANCE IN MICROBIOLOGY

ISO stand for  International Standard Organization is one of the leading international organizations that has brought the international community together to develop consistent quality standards in the manufacturing and services industries.

Quality: Quality means meeting the user’s predefined requirements for a specific substance or service.Quality includes the following :

  • Total Quality Management (TQM)
  • Continuous Quality Improvement (CQI)
  • Quality Assurance (QA)

TQM evolved into an activity to improve patient care by having the lab monitor its work to identify deficiencies and then correct them

CQI and PI seek to improve patient care with a focus on non-error in the first place

Quality assurance is associated with the three phases of quality control (qa qc) which are :

  • Pre- analytical
  • Analytical
  • Post analytical

Pre-analytical

Sampling or specimen collection : The material must be from the actual site of infection.It should be properly collected with minimal risk of contamination.It should be collected in a sterile container of adequate size.In case of tonsillitis, the throat swab should be taken from the inflamed peritonsillar fossae.Pus should be collected from the inflamed area near the edges of the abscess and should not be collected from the center of the abscess were dead and necrotic material is likely to be present.

Optimal time : The sample must be taken to get the best chance of recovering the causative microorganism from the sample.For example, In typhoid fever, blood culture should be performed during the first week of fever.The WIDAL test should be performed at the end of the second week of fever.The sample should be taken before administration of an antibiotic.If the patient is taking antibiotics, the sample should be taken before the next dose of antibiotic is administered.

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A sufficient amount of sample should be collected to perform the required tests. For example, 5 – 10 ml of blood should be collected in the blood culture bottle.

When collecting samples, appropriate collection devices and sample containers should be used.All containers used to collect the culture samples should be sterile.The handling of the containers should also be such as to preserve the sterility of the container at all times during the collection of the sample.

Labelling of the sample should be proper to ensure that the sample is not confused.

Proper selection of culture media should be made to ensure that the pathogenic organisms are isolated from the sample. Fastidious organisms such as streptococci and meningococci may use blood agar and chocolate agar for isolation.

The sample should also be taken for direct microscopy and appropriate smears should be taken.

Specimen transportation: The main purpose of transporting diagnostic specimens, whether within the hospital, out of the clinic, or externally by post or transport to a remote reference laboratory, is to keep the specimen as close as possible to its original condition.If a longer delay is expected before the sample can be processed, it is generally preferable to freeze the sample at 70 ° C.Freezing at -20 ° C can be used for many samples when storage time is short.Storage should not take place in a frost free refrigerator.

Transport media: Some transport media ’s are available for microbiology specimen e.g. Stuart ’s media, Cary-Blair media

Specimen receipt and Preliminary observations: The initial observation and handling of the sample should be carried out carefully. When handling the sample, general safety precautions should always be followed. If necessary, personal protective equipment such as gloves and masks should be worn.

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Acceptance of specimens includes the following:

Documentation of the essential data in a logbook.Visual inspection of the sample for appropriateness.Samples that do not meet the acceptance criteria should be rejected.It is always a good idea to set the rejection criteria.For example, the saliva is rejected when a sputum sample is to be taken.A well-formed stool is not the right sample for hanging drop preparations to test for the mobility of Vibrio cholerae bacteria.

Analytical

The analytical phase includes the following:

  • Training of the staff:The quality system is only as good as the people who actually work with it.No matter how good the quality system on paper is, if the theory can not be put into practice, quality can not be achieved.The training of the staff is essential to achieve the goals of the quality system.The training must include an understanding of the importance of quality.Post training support is also essential to ensure continued competence of the staff.
  • Microscopic examination of specimen: The microscopic examination of the clinical sample is performed to detect the presence of pathogenic bacteria, neutrophils, etc. It can also be used to assess the suitability of the sample for acceptance or rejection.
  • Processing of specimen: Proper processing of microbiology samples involves the proper selection of culture media, maintenance of the optimal incubation temperature and atmosphere, and proper characterization of the isolated pathogen through appropriate biochemical reactions and antibiotic susceptibility tests.
  • Monitoring and evaluation:  The laboratory management must develop and implement quality indicators to systematically monitor and evaluate laboratory ’s contribution to the patient care.Quality assessment through audits (internal or external) is a must.The laboratory shall participate in an external quality assurance programme.It is also possible to do interlaboratory comparisons of test results.Internal quality is also essential for evaluating technician skills and the performance of automated equipment.
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Post – analytical

Reporting of results:  Reports on microbiological culture outcomes should be prepared as soon as useful information is available.Each laboratory must establish those results that will be considered “ Urgent ” or “ critical ”. In addition, some results may be considered important but are not necessarily urgent.For example, if a pathogenic bacterium is observed in the direct microscopic examination of cerebrospinal fluid, this should be regarded as a critical result.The detection of metachromatic granules in a Gram positive bacilli on Albert’s stain is suggestive of Corynebacterium diphtheria and hence is considered as a critical result.

Analysis of results: It is up to the laboratory director to give the clinician feedback on some parameters of the laboratory’s performance. Turn around time (TAT) studies and susceptibility to microbial susceptibility are helpful to clinicians.

Benefits of Quality assurance programs

These include the following

  • Production of quality products and reliable services
  • Motivational factor for staff to work better.
  • Creating a good reputation for the lab.
  • Prevent litigation and related complications

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About the Author: Arthur Westmann

DEFFE ARTHUR (AMOEBAMANN) is the founder and author of MLTGEEKS and MLTEXPO.He’s from Cameroon and is currently a Final year State Medical Laboratory Technician (MLT MA). Beyond lab works, he’s a passionate internet user with a keen interest in web design and blogging. Furthermore He likes traveling, hanging around with friends and social networking to do in his spare time.