ASO Latex Slide Test(Rapitex Slide)

Group 6

Parco, Genkei T.Parlan, King Joseph A.Pasion, Angela M.Quitasol, Marion Coleen E.Racelis, Riza Alyana K.Reyes, Cherry Rose T.Roldan, Michael B.

ASO Latex Slide Test(Rapitex Slide)

Rapid slide agglutination test for the direct detection of anti streptolysin O, a substance produced by Group A Streptococcus bacteria.

Streptococci

Gram-positive

cocci

Spherical, ovoid or lancet-shaped

organisms

Often seen in pairs or

chains

Hemolytic streptococci are

divided into Lancefield

Groups (A-O) depending upon group specific carbohydrates

Streptococcus pyogenesLancefield group A

Beta-hemolytic

Ubiquitous pathogenic bacteria which causes variety of infections

i.e. pharyngitis, scarlet fever, impetigo

Development of complications such as acute rheumatic fever and poststreptococcal

glomerulonephritis

Exoantigens

Hemolysins:

Streptolysin O (SLO)

Oxygen-labile enzyme

Binds to sterols in the red blood cell causing stearic rearrangement

Antigenic

Description of Diseases

Characteristics of Streptococcal Infection

Two major sites of infection in human:

a. Upper Respiratory Tractb. Skin with pharyngitis & impetigo (most common)

Strep ThroatStreptococcal

pharyngitisCaused by group A

streptococcal bacteria, Streptococcus pyogenes.

Affects the pharynx and possibly the larynx and tonsils

Not all sore throats are strep throats

Signs and symptoms of Strep Throat

Inflamed tonsilsWhite spots on the tonsilsDifficulty swallowing

(dysphagia)Bumps, bruises,

inflammation, or swelling; (goose eggs), on the right, or uncommonly left side of neck.

FeverHeadache(often prior to

other symptoms)

Malaise, general discomfort, feeling ill or uneasy

HalitosisAbdominal pain, nausea and

vomitingRashHivesChillsLoss of appetiteEar painPeeling of skin on hands and

feet

Scarlet FeverCaused by an

erythrogenic exotoxin released by Streptococcus pyogenes.

Toxin (poison) that can cause the scarlet-colored rash

Streptococcal pyoderma

ImpetigoCaused by

Streptococcus pyogenes

Most common skin infection

Rheumatic feverA disease that may begin

with a streptococcal infection that was not properly treated with antibiotics. (e.g. Strep throat & Scarlet fever)

Serious damage to the heart, joints and kidneys. (an immune response to an infection with group A streptococcus.)

May proceed to endocarditis.

Symptoms of Rheumatic Fever

- Abdominal distress- Confusion- Cough- Fatigue- Fever- Joint pain and

swelling - Muscle pain - Nosebleeds

- Rashes- Skin nodules - Speech impairmentsunusual jerky

movements - Vomiting- Weakness

Poststreptococcal Glomerulonephritis- Inflamed glomeruli- result of an infection, not of

the kidneys, but of a completely different area, such as the skin or throat, with a specific type of Group A hemolytic streptococcus bacteria.

Risk factors include:- Sore throat- Strep throat- Streptococcal skin infections (such as impetigo)

Poststreptococcal GlomerulonephritisSymptomsCough, with sputumDecreased urine outputEdema (swelling)Smoky urine and Rust-colored urineVisible blood in the urineOther symptoms may include: Joint pain and

Joint stiffness.

Serodiagnostic Tests for Streptococcal Diseases

A. AntiStreptolysin O (ASO Test)

Principle: The presence of sufficient anti-Streptolysin O antibodies in a serum specimen will result in the neutralization of the hemolytic action of the streptolysin O reagent. This neutralization is indicated by the absence of hemolysis in the test system.

B. Streptozyme Rapid Slide Test is an agglutination test that detects antibodies to five group A

streptococcal exoantigens, including:

• Streptolysin O

• Streptokinase

• Hyaluronidase

• DNase B

• NADase

Principle: Suspension of aldehyde fixed sheep cells sensitized with Streptococcus A extracellular antigens will react with their corresponding antibodies in the patient’s

serum to give a positive agglutination reaction.

Serodiagnostic Tests for Streptococcal Diseases

ASO Latex Slide Test (Rapitex Slide)PRINCIPLE:

Streptolysin O bound to polystyrene latex particle would react immunologically with its corresponding antistreptolysin O antibody in the patient’s serum,

thereby a visible agglutination is observed.

ASLO Test procedureBring the reagents

and samples to

room temperatur

e.

Use pipette stir/stick to deliver 1 drop (50ul) of the test

serum into separate circles on the card.

Place 1 drop of Positive Control and

Negative Control into two rings on the slide

(#1 and 2).

Resuspend ASO Latex reagent gently and add

one drop to each test field.

Mix well with the flat end of the pipette and spread over the entire area enclosed by the

ring. Use a new stirrer for each

sample.

Rotate the cards at 100 rpm for 2

minutes inthe mechanical

rotator and read immediately under direct

light.

Limitations of the Procedure:

Positive results may be obtained in conditions other than rheumatic fever and glomerulonephritis such as scarlet fever, various streptococcal infections and even in healthy carriers.

False negative reactions may occur in early primary infections and children aged between 6 months and 2 years of age.

Notes:The sensitivity of the test may be reduced at low

temperatures. The best results are obtained over 10°C.Delay in reading the results may result in over-

estimation of the ASO level.

ANTIGEN

•Streptolysin O - is one of the exoantigens released by streptococcal bacteria as they grow.

•Polystyrene latex particles coated with streptococcal exoenzymes.

ANTIBODY

•The antibody detected was the Anti- Streptolysin O.

•Agglutination

Ring 1 Ring 2 Ring 3 Ring 7 Ring 8 Ring 9 + 0 0 0 0 0w/ agglutination no agglutination noagglutination no agglutination no agglutination no agglutination

Ring 4 Ring 5 Ring 6 Ring 10 Ring 11 Ring 12 0 0 0 no agglutination no agglutination no agglutination

Results:

Ring 1 – with agglutination presence of visible agglutination is due to the positive control

serum containing antistreptolysin O that reacted with the antigen.

Ring 2 – no agglutinationabsence of anti streptolysin O in the negative control serum.

Ring 3 -9 – no agglutinationall the test serum use does not cause agglutination to the antigen with streptolysin O due to the absence of anti streptolysin in the serum.

Presence of antibody (anti streptolysin O) in the serum causes agglutination reaction to the antigen (streptolysin O). Having anti streptolysin O in the serum indicates the presence of Streptococci.

Interpretation:

Thank You!!!