Micro Test 2

Front 1

pathogenicity

Back 1

the ability of a microorganism to cause a disease

Front 2

virulence

Back 2

the degree of pathogenicity

Front 3

LD50

Back 3

number of microbes in a dose that will kill 50% of inoculated test animals (lethal dose 50%)

Front 4

ID50

Back 4

number of microbes in a dose required to cause an infection in 50% of population

Front 5

adherence

Back 5

enhances pathogenic potential, necessary step for most pathogens.

Front 6

adhesins

Back 6

molecules on the pathogen that bind to the host cell receptors

Front 7

Capsules on pathogens

Back 7

penetrate host defenses by resisting phagocytosis by leukocytes

Front 8

leukocidins

Back 8

enzyme that destroy neutrophils

Front 9

hemolysins

Back 9

enzyme that can lyse erythrocytes

Front 10

coagulases

Back 10

enzyme that can clot blood

Front 11

kinases

Back 11

enzyme that dissolve clots

Front 12

hyaluronidase

Back 12

enzyme that breaks down 'cell cement'

Front 13

collagenase

Back 13

enzyme that breaks down collagen in connective tissue

Front 14

proteases

Back 14

enzyme that breaks down proteins in muscle

Front 15

lecithinase

Back 15

enzyme that destroys plasma membranes

Front 16

Antigenic variation

Back 16

microbes alter their surface to evade immune system

Front 17

Penetration into cytoskeleton

Back 17

invasins rearrange actin filaments to propel pathogens into cell

Front 18

Toxins

Back 18

poisonous substances produced by some pathogens - most important substances of pathogenicity; exotoxins and endotoxins

Front 19

Exotoxins

Back 19

proteins produced inside pathogenic bacteria (most Gram +) then secreted into surrounding media following lysis

Front 20

A-B Toxins

Back 20

exotoxin - A (active) component is the enzyme. B (binding component) binds to host cell receptors and brings the enzyme into the cell

Front 21

Membrane-disrupting toxins

Back 21

(leukocidins, hemolysins) form channels in plasma membrane or disrupt phospholipid bilayer. this kills the cells

Front 22

superantigens

Back 22

proteins that provoke intense immune response; t-lymphocytes produce very high levels of cytokines that lead to fever, gi symptoms, shock and death

Front 23

cytotoxins

Back 23

kill host cells or affect their function

Front 24

neurotoxins

Back 24

interfere with nerve impulse transmission

Front 25

enterotoxins

Back 25

affect cells lining the gastrointestinal tract

Front 26

Endotoxins

Back 26

lipid portions of lipoplysaccharides (LPSs) that are part of the outer membrane of cell walls of gram- bacteria. these toxins are liberated when the cell dies and the wall breaks apart

Front 27

septic shock (endotoxic shock)

Back 27

shock caused by gram- bacteria. phagocytes ingest GNB produce "tumor necrosis factor" which damages capillaries, increases their permeability, causing large fluid loss and drop in BP

Front 28

Pyrogenic response

Back 28

(fever) to endotoxin caused by macrophage production if interleukin-1

Front 29

Pathogen evasion of host defenses

Back 29

grow inside cell, attachment sites mimic useful things to cells, attachment sites can also be hidden to immune system

Front 30

Cytopatic effects (CPE)

Back 30

visible effects of viral infection in cell culture: inclusion bodies, rounding, giant cell formation, cell death

Front 31

Ciliary Escalator

Back 31

Microbes in lowe rrespiraroy tract are trapped in mucus by goblet cells then propelled upward by cilia.

Front 32

Plasma

Back 32

liquid, non-cellular portion of blood

Front 33

Serum

Back 33

plasma without blood clotting proteins

Front 34

phagocytosis

Back 34

ingestion of microbe particles. Carried out mainly by neutrophils, eosinophils and macrophages

Front 35

chemotaxis

Back 35

chemical attraction o fphagocytes to mircoorganisms

Front 36

adherence

Back 36

attachment of phagocyte's plasma membrane to surface of microbe (enhanced by opsonization)

Front 37

ingestion

Back 37

pesudopods engulf microbe and form a phagosome

Front 38

digestion

Back 38

phagolysosome forms, digestive enzymes and bactericidal substances destroy microbe. residual body transports waste outside cell.

Front 39

inflammation

Back 39

destroys and removes injurious cells, walling off contamination, repairs damaged area.

Front 40

interferons

Back 40

antiviral proteins produced by animal cells to interfere with viral multiplication (not virus specific)

Front 41

immunity

Back 41

specific defensive responses to foreign organisms or other substances

Front 42

Antigen (Ag)

Back 42

substance that provokes a specific immune response

Front 43

Antibody (Ab)

Back 43

protein made in response to an antigen which can recognize and bind to that antigen (also called immunoglobulin (Ig)

Front 44

epitope

Back 44

specific region on an antigen that interacts with Antibody

Front 45

Acquired immunity

Back 45

specific resistance to infection developed during the life of the individual

Front 46

Humoral / antibody-mediated immunity

Back 46

involves production of antibodies by B lymphocytes

Front 47

Cell-mediated immunity

Back 47

involves specialized T lymphocytes that act against foreign cells

Front 48

Hapten

Back 48

molecule too small to stimulate Ab formation by itself, but can do so when attached to a larger carrier molecule

Front 49

apoptosis

Back 49

programmed cell death. Rids body of unneced cells, including B-Cells that do not find their specific antigen.

Front 50

Helper T cell immunity

Back 50

1. APC (dendritic cell) encouters/engulfs microorganism, breaksdown the antigen which combindes with MHC II molecules and are displayed on the surface of the sell
2.a receptor on the CD4+ T-helper cell binds to MHC II/antigen. CD4+ cell activates and produces cytokines
3. CD4+ cell proliferates and develops effector functions

Front 51

Cell-Mediated cytotoxicity

Back 51

1. CTL (cytotoxic t lymphocyte) detects abnormal cell endogeneous antigens
2. abnormal antigens are presented on the surface with MHC 1. CD8+T cells w receptors are transformed to CTLs
3. destruction of cell by apoptosis

Front 52

How T-Cells active B cells to make antibody against t-dependent antigens

Back 52

1. Ag is ingested by APC and partially digested. frags combinde with MHC and are presented on cell surface
2. Helper t cells specific for presented antigen interact with complex
3. helper cells activate an appropriate B cell. as well as antigen receptors
4. interaction triggers B cells to differentiate into plasma cell - secreting antibodies specific for the t-dependent antigen

Front 53

vaccine

Back 53

suspension of microorganism of fractions of microorganisms used to induce immunity

Front 54

attenuated whole-agent vaccine

Back 54

uses living but weakened microbes

Front 55

inactivated whole-agent vaccine

Back 55

uses killed microbes

Front 56

toxoid

Back 56

inactivated toxin that induces immunity response against toxin

Front 57

subunit vaccine

Back 57

antigentic fragments of a microbe that stimulates an immune response

Front 58

conjugated vaccine

Back 58

combination of antigens that enhance immune response

Front 59

Nucleic Acid vaccine

Back 59

naked microbe DNA injected, transcribed and translated into protien by the animal, immune response directed towards protein - experimental

Front 60

adjuvant

Back 60

substance that enhances effectiveness of antigens

Front 61

titer

Back 61

reciprocal of highest dilution given a positive result

Front 62

Seroconversion

Back 62

4-fold or greater increase in the titer between acute and convalescent phase = indicates infection

Front 63

aggutination

Back 63

rxn of particulate antigens with antibodies to form visible aggregates

Front 64

direct agglutination

Back 64

identify known bacteria types using known antibodies

Front 65

Indirect Passive Agglutination

Back 65

1. Rxn for Ab = particles coated with antigens / agglutination indicates presense of antibodies
2. rxn of particles covered by antigens and agglutination indicates presence of antibodies