Lab 30: Staphylococcus aureus Rapid Test

Lab 30: Staphylococcus aureus  Rapid Test 

1. Rapid Tests= immunological assays that use Ag-Ab rxns to identify a specific organism or agent

-give results within minutes and can be run in hospitals labs or dr. offices

-In this lab, we do Passive Agglutination Test for Staphylococcus aureus

Passive Agglutination Test= uses latex beads coated with anti-Staph antibodies to detect S. aureus

-test kit comes with positive and negative controls 

-test samples come from beta hemolytic colonies cultured from throat swabs grown on sheep’s blood agar plates

+= if S.aureus antigen is present and binds to Abs= agglutination = clumping

-= no clumping

-Indications of Positive Test

a. A Positive test combined with appropriate signs/symptoms can confirm dx of S.aureus infection

S. aureus= Gram + non motile coccus

-responsible for wide array of diseases including:

a. skin infections= most common

-including: pimples, impetigo, boils, carbuncles, and cellulitis

b. surgical and would infections are common and can spread to internal organs causing other disease like pneumonia or septicemia

c. Staphylococcal food poisoning and toxic shock syndrome from toxins produced from certain strains of Staph

b. Can indicate that person is a healthy carrier= healthy, asymptomatic carrier of S. aureus  in their noses/throats or skin, but NO symptoms of disease

-25-50% of population =health carriers of S. aureus 

-healthy carriers can still spread Staph to others 

-even resistant strains of Staph like MRSA (methicillin-resistant S. aureus) can be found in healthy carriers

- important for healthcare workers who are healthy carriers but are alsoaround immunocompromised patients- could be very harmful if spread to them

Wells 4,5, 10= positive =clumping

Well 9= negative= no clumping