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