به نام خدا. PT/EQAS Microbiology Discipline Dr. Marjan R. Farzami [email protected].

خدا نام به

PT/EQAS

Microbiology

Discipline

Dr. Marjan R. [email protected]

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


• Includes :

- Bacteria with great public health

importance

- Common bacteria laboratories encountered

with

- Familiar pathogens with special

antimicrobial resistance profile


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


• Transport/Safety issues

• Stability issues


• 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)


• Expected

- Limited microorganisms can be selected

due to safety issues


• 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


• 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


• Clinical relevancy

- relevancy of reports

-relevancy in susceptibility

challenges


• Variety of challenge styles

- Slides (colored & uncolored)

- Mixed specimens

- Selecting appropriate antibiotics for

identified strains

- Images


• 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


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 ”


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

به نام خدا. PT/EQAS Microbiology Discipline Dr. Marjan R. Farzami [email protected].

Documents