What are Antigens?

Molecules that stimulate a response by T and B cells

What are the two features that characterize specific immunity?

Specificity - antibodies produced and function only against the antigen they were produced in response to

Memory - lymphocytes are programmed to "recall" their first encounter with an antigen

What are the major functions of receptors

1. to perceive and attach to "nonself" or foreign molecules

2. to promote the recognition of self-molecules

3. to receive and transmit chemical messages among other cells of the system

4. to aid in cellular development

What is the Major Histocompatibility Complex?

on all cells but RBCs, play a role in recognition of self and rejection of foreign tissue

What are Class I Major Histocompatibility Complex genes responsible for?

markers that display unique characteristics of self molecules and regulation of immune reactions (required for T lymphocytes)

What are Class II Major Histocompatibility Complex genes responsible for?

regulatory receptors found on macrophages, dendritic cells, and B cells (involved in presenting antigen to T-cells).

B-cell receptors

bind free antigens

T-cell receptors

bind processed antigens together with the MHC molecules on the cells that present antigens to them

What are the 2 types of T-cells

Helper T-cells- stimulate B-cells to make antibodies and help killer cells develop

Killer T-cells- directly kill cells that have already been infected by pathogen

What is Opsonization?

process of coating microorganisms or other particles with specific antibodies so they are more readily recognized by phagocytes

What is Neutralization?

Abs fill the surface receptors on a virus or the active site on a microbial enzyme to prevent it from attaching.

What are the 5 classes of immunoglobulins? GAMDE

IgG

IgA

IgM

IgD

IgE

What are Presumptive results

based on reasonable clinical signs, informed guess

What are Confirmatory results

tests, confirms the presence of microbes

What are PCR products called?

Amplicons

What is Serology?

in vitro (in artificial environment) testing of serum

visible reactions include precipitates, color changes, or the release of radioactivity

What is Sensitivity

true positive rate

high sensitivity test has low false positive rate

What is Specificity

true negative rate

high specificity test has low false negative rate

Agglutination testing

antibodies cross link whole cell antigens, forming complexes that settle out and dorm large visible clumps (you can see them with your naked eye).

USES WHOLE ANTIGEN

What is the Widal test used for?

presumptive diagnosis of salmonellosis and undulant fever (Brucellosis)

What is an epitope

antigenic determinant

Precipitation testing

soluble antigen is made insoluble by an antibody

Can PCR tell you if a virus is dead or alive?

No, PCR only detects nucleotides and cannot tell if a virus is dead or alive or if a person is sick or recovering

Western Blot

highly specific and sensitive electrophoresis and immunoassay, 2nd HIV determinate test, good to determine active infections

What does ELISA stand for?

Enzyme-linked immunosorbent assay

What are 7 ways to test viral infections?

1. Signs and Symptoms

2. Cells are taken and examined (fluorescent staining)

3. Electron Microscopy

4. Serological testing

5. PCR

6. Culture techniques

7. ELISA method

What does PPD stand for?

purified protein derivative

What are the 2 major species of Staphylococcus?

S. aureus

S. epidermidis

What does MRSA stand for?

Methicillin resistance staphylococcus aureus

When preforming the coagulase test you notice your bacteria forms clots spontaneously is it S. aureus or S. epidermidis

S. aureus forms clots

You plated your unknown Staphylococcus bacteria on an MSA plate and noticed it fermented mannitol and turned the medium yellow is it S. aureus or S. epidermidis

S. aureus ferments mannitol

Is S. aureus Beta or Gamma hemolytic

S. aureus is Beta hemolytic

Is S. epidermidis Beta or Gamma hemolytic

Gamma (non) hemolytic

Common Staphylococcal diseases

Folliculitis

Furuncle

Carbuncle

Impetigo

Folliculitis (Staphylococcal disease)

superficial inflammation of hair follicle

Furuncle (Staphylococcal disease)

boil, abscess or pustule

Carbuncle (Staphylococcal disease)

larger and deeper lesion created by aggregation and interconnection of a cluster of furuncles

Impetigo (Staphylococcal disease)

bubble-like swellings that can break and peel away; most common in newborns with poor hygiene

Scalded skin syndrome (Staphylococcal disease)

result of endotoxin produced by S. aureus which induces bright red, flush, blisters then desquamation of the epidermis.

Toxic Shock Syndrome (Staphylococcal disease)

S. aureus colonization of the tampon resulted in large amounts of exotoxin being absorbed into the body

Food poisoning (Staphylococcal disease)

S. aureus grows and produces exotoxins in food that was left out and kills the bacteria in our gut RAPID ONSET

INFECTS THE FOOD NOT US

What are examples of Universal Precautions

Hand hygiene, protective barriers, TB tests + vaccinations, confidentiality

Describe Staphylococci bacteria

Gram-positive cocci

grape-like clusters

facultative anaerobe (with or without oxygen)

O/F fermentative