brucellosis - lecture notes - tiu - lecture notes

Ms. Chnar Hussam Dr. Tola FARAJ__________________________________________________

Immunology_ 2nd Stage/2nd Semester

https://tiu.edu.iq/

2020 - 2021

TIU - Faculty of Science

Medical Analysis Department

Brucellosis

Lab.7

Lab outlines:

5 minutes all settle in the lab. with

attendance

5 minutes Quiz

15-20 minutes pre-lab (10 ppt slides

including the Introduction and detail

of the practical part)

20 minutes practical part

Leave the lab 5 minutes earlier

BrucellosisRose Bengal test

What is brucellosis?

• Brucellosis is a disease caused by a group of bacteria from the genus Brucella. These bacteria can infect both humans and animals.

• Brucellosis is often spread when people eat contaminated food, which may include raw meat and unpasteurized milk. The bacteria can also be spread through the air or contact with an open wound. Humans can then contract the disease from infected animals.

• The bacteria can be transmitted via:

• ingestion (eating)

• inhalation (breathing)

• contact with an open wound

• If treatment isn’t successful, brucellosis can cause complications. These may include:

• encephalitis (inflammation of the brain)

• epididymo-orchitis (inflammation of the testicles)

• lesions on the bones and joints

• endocarditis (infection of the heart’s inner lining)

• meningitis (inflammation of the membranes around your brain)

What are the symptoms of brucellosis?

• Fatigue

• Fever

• Sweating

• Headache

• Muscle, joint, back discomfort

• Weakness, ill-feeling

• Loss of appetite

PRINCIPLE

• The Rose Bengal Test or buffered Brucella antigen test (BBA) is a rapid slide agglutination procedure developed for the direct detection of Brucella antibodies in human and animal sera. The bacterial suspension is reactive with both immunoglobulin G and immunoglobulin M antibodies being the former detected earlier (sub-clinical infections) and over a large period during the disease (chronic stage) than the conventional tube agglutination test. The assay is performed by testing the buffered suspension (pH 3.6) of B. abortus strain colored with Rose Bengal against unknown sera. The presence or absence of a visible agglutination, indicates the presence or absence of antibodies in the samples tested

REAGENT COMPOSITION

• Rose Bengal Antigen. Bacterial suspension of B. abortus stained with Rose Bengal and buffered at pH 3.6

• CONTROL + Brucella. Anti-Brucella animal serum.

• CONTROL - Animal serum with an agglutinating activity .

How is brucellosis diagnosed?

• Brucellosis is diagnosed through a sample of blood or bone marrow which is sent for bacterial culture, serology (antibodies to the bacteria) or molecular testing (polymerase chain reaction or PCR).

STORAGE AND STABILITY

• Store at 2-8ºC. Do not freeze. Frozen reagents could change the functionality of the test. Antigen and Controls are stable until the expiry date stated on the label.

SAMPLES

• Fresh, clear serum. After the clear serum has been separated it may be stored at 2-8ºC up to one week or for longer periods at –20ºC

PROCEDURE

1. Bring the test reagents and samples to room temperature . Resuspend the antigen vial gently. Aspirate dropper several times to obtain a thorough mixing.

2. Place 1 drop of the serum under test into one of the circles on the card.

3. Dispense 1 drop of positive control serum and 1 drop of negative control serum into two additional circles.

4. Add 1 drop of Rose Bengal Antigen to each circle next to the sample to be tested.

5. Mix the contents of each circle with a disposable stirrer while spreading over the entire area enclosed by the ring.

6. Use separate stirrers for each mixture. Rotate the slide slowly for a period of 4 minutes.

7. Observe immediately under a suitable light source for any degree of agglutination.

Slide procedure:-

Test tube procedure:-

Reading

• Nonreactive: Smooth suspension with no visible agglutination, as shown by negative control.

• Reactive: Any degree of agglutination visible macroscopically. All reactive specimens should be further tested to clarify the situation.

Result

Quick quiz for today labread the result below?

Thanks