Blood Culture Analyzers

Automated; Mycobacteria Detection System

Group 9

What is blood culture?

Laboratory test in which blood is injected into bottles with culture media to determine whether microorganisms have invaded the patient’s bloodstream or not.

Blood cultures are ordered as a set, which consists of 2 bottles (1 aerobic bottle & 1 anaerobic bottle).

Principle for collection of blood

1. Wear gloves2. Cultures should be drawn before

administration of antibiotics, if possible.

3. Blood should be drawn via venipunture.

Venipunture

Collection of blood from a vein, usually from elbow or back of hand

Step-to-do

Steps 1-3 –Check, Explain, Wash1. Identify the patient by checking the

arm band or area-specific procedure.2. Explain the procedure to the patient.3. Wash hands with soap and water with

friction for 15 seconds or use alcohol based hand rub.

Step 4 Decontaminate blood culture

bottle topsRemove lids and disinfect rubber access points with an alcohol based disinfectant

Step 5 Apply alcohol based skin antiseptic and

leave to dryPatient’s skin is decontaminated at insertion site with alcohol based antiseptic and is allowed to dry for 30 seconds before taking the blood culture

Step 6Draw blood. Note the appropriate volume to obtain: Example

Step 7Mix - Gently rotate the bottles to mix the blood & the broth (do not shake vigorously).

Step 8 & 9 Label, send and documentation

1. Label the culture bottle with patient ID2. Send the culture bottle to Clinical Microbiology

3. Record the time, date specimen obtained and site of specimen obtained

PROCEDURE TAKING BLOOD CULTURE

Principle operation

CELL CONCENTRATION CURVE

BLOOD WILL BE

PUT IN NUTRIENTS

MEDIUM

STARTING TO GROWTH AS FOUND NEW

NUTRIENTS

EQUAL CELL REPRODUCTION

AND DEATH

RATE OF DEATH EXCEED RATE

OF REPRODUCTION

METHOD DETECT MICROBIAL PRESENCE

Use fluorescence

EMITS

REACTS

FLUOROMETER

EMITS a wavelength that is longer than the

wavelength of the LIGHT IT ABSORBS

FLUORESCENCE COUNTER

REACTS in the presence of microorganisms to

produce a NONFLUORESCENT

PRODUCT

METHOD DETECT MICROBIAL PRESENCE

Using Colorimetry

THE DETECTION OF COLOR CHANGES IN PH INDICATORS CAUSED BY METABOLIC END

PRODUCTS.

METHOD DETECT MICROBIAL PRESENCE

Photoelectric cell

MEASURES CHANGES IN THE REFLECTANCE OF LIGHT AT THE BOTTOM

OF THE CULTURE BOTTLE.

METHOD DETECT MICROBIAL PRESENCE

Measures changes in the pressure of the headspace in blood culture bottles

Automated blood culture analyzers have computer programs to determine the final test results.

 AIR-TIGHT SEAL IN THE CULTURE

BOTTLE

 SENSOR MONITORS THE POSITION OF THE

SEPTUM, WHICH CHANGES WITH AIR PRESSURE, DUE TO MICROORGANISM

ACTIVITY

Detect both gas consumption

and production

Reported Problems

Reported Problems

1. Inadequate sample volume

2. Contamination during sample collect and preparation

Problems :

Solutions :Operators should:

The specimens must be processed A.S.A.P after arriving in the laboratory to minimize changes to the microenvironment.

- exercise care to eliminate substance that might interfere with the analysis

- paying particular attention to specific sources of error for specific test methods.

Purchase Consideration

Purchase Consideration

1. Whether the detector can accept future hardware upgrades

2. Whether the unit can interface with other laboratory instruments (e.g., automated microbiological systems) that can provide additional parameters.

3. Choose an instrument that can handle both adult and pediatric samples

4.  purchase an automated blood culture analyzer with a data management system. 

Bar-code labeling :

- Allow patient results to be matched to printed results

- A convenient long-term storage

- Easier for physician review or entry into a data

management system

Purchase Consideration

5. Purchase additional mandatory quality control (QC) strains, usually from a third party

6. The effectiveness of the system’s interface with the hospital’s central computer system according to CLIA guidelines.

7. Enviroment: look for manufacturers who offer take-back programs on system components

8. Cost :- Warranty agreements, maintenance contracts, and software upgrades

Should purchase service contract

Stage of DevelopmentBlood culturing has remained a stable

technology for many years. Improvements include faster detection time, smaller footprint,

and comprehensive data processing and storage.

Researchers are exploring the use of molecular diagnostic techniques such as polymerase chain reaction and chip array, which are currently used in DNA research, to perform rapid blood testing. These techniques, which are increasingly being

used for detection of Methicillin-resistant Staphylococcus aureus (MRSA), may prove to be quicker and more efficient than traditional blood

culture analysis