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Main categories in PT/EQA program
• Quantitative tests
• Qualitative tests
Qualitative data
• Categorical measurement expressed by means of a natural language description
- Nominal e.g. organism name/identity, genotype,
presence/absence, positive/ negative
- Ordinal e.g. 1+, 2+, 3+ (can be ordered) but
have no algebraic relationship
Qualitative Data Analysis
‘There is no such thing as
qualitative data.
Everything is either 1 or 0 !!’
What is different in Microbiology Discipline
• Lack of availability of real samples
• Statistics & performance scoring
•Methodology
• Unpredictable behavior of
microorganisms
What is the current program?
Design of the program
• 3 times per year
• 2 samples per round
•One isolate is selected for
antimicrobial
susceptibility testing
Grouping Why & How
• Hospital versus Independent
laboratories
- Expectations
- Different challenges Same approach in analysis!
Selection of specimens
• Considering :
- Prevalent diseases
- The tests being done in routine
services
- Biosafety issues & Ease of dispatching
Selection of specimens
• Includes :
- Bacteria with great public health
importance
- Common bacteria laboratories encountered
with
- Familiar pathogens with special
antimicrobial resistance profile
Selection of specimens
1. ATCC strains or WHO selected isolates provided from Reference Laboratory-MoH
2. Full range of Biochemical tests
3. Serotyping and other additional tests (if needed)
4. Antimicrobial susceptibility testing
5. Determining the parameters for evaluation (key identifiers)
In process Quality control of specimens
1. Quality control of media which isolate is inoculated in or should be inoculated
2. Complete re-examination of randomly selected samples before packaging and after transport (in a defined period of time) for :
- Stability
- Purity(Absence of contamination)
- Homogeneity (count)
Internally and Externally by our referral laboratories
Production of specimens
A set of two vials with lyophilized bacterial suspensions of different strains or mixed selections for each participant
- One specimen is common between two groups
(Identification and Susceptibility testing)
- One separate specimen for each group
(Identification)
-
Packaging & Shipment
• Each specimen inoculated in an appropriate medium and packed in a triple layer container
• Lyophilized strains (accompanied by the instruction for preparing sample)
Analysis of results
• Identification of strains:
- Considering parameters for evaluation (key identifiers)
for each strain
- The role of each parameter in correct diagnosis
determines its value in scoring system
- Special/Critical points for reporting to clinician
- Scores are :0-3 (Based on a scoring system similar to WHO program )
Analysis of results
• Identification of strains:
Parameters for evaluation (key identifiers) are most often:
- Use of appropriate media
- Colony morphology
- Gram stain and the observations
- Biochemical tests & results
- Additional tests & results
- Final identification & wording used in the report given to clinician
Scores :
0-3
Analysis of results
• Antimicrobial susceptibility testing:
According to the latest CLSI guidelines 5 pre-determined antibiotics for one of the isolates are selected
Report of actual results should include:
- Diameter of growth inhibition
- Interpretation of results (S,I,R)
Challenges & Limitations
Challenges & Limitations
• Transport/Safety issues
• Stability issues
Challenges & Limitations
• Expected
No growth of specimen in an acceptable percent
due to :
- Selected isolate(e.g. fastidious microorganisms)
- Delay in shipment service for remote labs
( more than 3 days)
Challenges & Limitations
• Expected
- Limited microorganisms can be selected
due to safety issues
Challenges & Limitations
• Unexpected
-Not reporting the full range of biochemical and
other necessary tests
- Lack of enough communication
(reporting the problems timely)
There is no sterile sample in current
microbiology discipline!!
Sources of errors
• Sample handling and storage errors
• Inadequate staff training
• Incorrect or inappropriate methods
• Equipment and culture media failures
• Lack of proper internal quality control program
• Reporting errors
94-1
Inducible Clindamycin
Resistant S.aureus
Instructions
93-2
Vancomycin Resistsnt
Enterococcus faecium
93-3
Acinetobacter baumannii
New Approach and Future Program
New approach and future program
• Clinical realism
• Clinical relevancy
• Variety of challenge styles
• New challenge targets
New approach and future program
• Clinical realism
- samples mimicking patient samples
- checking the entire examination
process
The Laboratory Cycle
The Patient
Report Interpretation
Report Creation
Report Transportation
Test Selection
Sample Collection
Sample Transportation
Traditional Microbiology PT/EQA
AnalysisAccession
The Patient
Report Interpretation
Report Creation
Report Transportation
Test Selection
Sample Collection
Sample Transportation
The Laboratory Cycle
Achievable Microbiology PT/EQA
AnalysisAccession
New approach and future program
• Clinical relevancy
- relevancy of reports
-relevancy in susceptibility
challenges
New approach and future program
• Variety of challenge styles
- Slides (colored & uncolored)
- Mixed specimens
- Selecting appropriate antibiotics for
identified strains
- Images
New approach and future program
• New challenge targets
- Deleting scoring system
- Analysis based on patient risk and
defining the
acceptability criteria according to
clinical importance
What we expect of EQA/PT ?
The strengthening of the medical laboratories:
• Changing procedures of identification following standard procedures , recommended by expert advisers.
• Performing necessary tests in relevant circumstances such as Methicillin resistance or ESBL testing routinely.
• Better implementation of internal quality control
(supplied standard strains / educational programs)
What we expect of EQA/PT ?
The reliable results of the patient samples:
• Increasing percentage of complete and correct answers specially in rounds containing same bacteria
Inducible Clindamycin Resistant S.aureus
1-94
Identification characteristics
Inducible Clindamycin Resistant S.aureus
REACTION TEST+ Catalase
Beta Hemolysis on Sheep Blood AgarR Bacitracin 0.04 unitS Furazolidone 100 µg+ Coagulase (Slide)
+ Coagulase (Tube)
+ DNAse
S Novobiocin 5 µg+ Urease
+ Nitrate Reduction
+ ArginineDihydrolase
- Ornithine Decarboxylase
+ Mannitol Salt Agar
+ D-zone Test
Key Identifiers
انتظار مورد نتیجه کلیدی تستهای
+ / G+ cocci in cluster Catalase / Gram stain
+ / + Coagulase / DNAse
نیم ردیفموجبکسر یک تستهای از یک گزارشهر عدم
. است شده امتیاز
D-Zone Test
دیسک • دو آگار، هینتون مولر محیط روی بر باکتری تلقیح از بعد
اریترومايسين gµ2کلیندامایسین بین gµ15و ای فاصله با 15-26را
مدت به آنرا و داده قرار محیط روی متر دمای 16-18میلی در ساعت
2±35 . از بخشی شدن صاف مشاهده کنیم می انکوبه سانتیگراد درجه
و باشد می اریترومایسین مجاورت در که کلیندامایسین رشد عدم هاله
انگلیسی حرف تصویر شبیه نمایی مقاومت Dایجاد وجود نشاندهنده
است ها میکروارگانیسم این در کلیندامایسین به القایی
AST report
• “ This isolate is presumed to be resistant on the basis of detection of inducible clindamycin resistance ”
Inducible Clindamycin Resistant S.aureus
Results
S.aureus
Inducible CLI.Resistant S.aureus
M.R.S.aureus
S.epidermidis
D_zone Test Positive S.aureus
Others
کواگوالز استافیلوکوکهای سایرمنفی
استرپتوکوکها
0 100 200 300 400 500 600
555
494
75
72
47
20
19
6
No. of Laboratories
متشکرم
