chapter 11 mechanisms of pathogenicity (diana's version)

Question 1

how do micoorganisms enter a host

(in other words)-> what does it mean?

Answer 1

how an organism can makes us sick

Question 2

true or false.

Because to be able cause an infection, absolutely fundamental for a virus to enter the body

Answer 2

True

Question 3

True or false.

germs must first penetrate host defenses in order to damage tissues and go on to cause disease?

Answer 3

true

Question 4

How do microorganisms enter a host ?
name the three

Answer 4

1.Mucous membranes
2.Skin
3.Parenteral Route

Question 5

Mucous membranes :
what are the (3) subgroups

Answer 5

1) respiratory tract
2) gastrointestinal tract
3)genitourinary tract

Question 6

Respiratory Tract:

Answer 6

the most common portal of entry
microbes are inhaled into the nose or the mouth
example : influenza, colds

Question 7

true or false.
(respiratory tract)
we breathe about 12 times per min, exchange 500 mL o air imagine ow much air is contaminated you are taking in every breathe these infection particle are going to be taken by this route

Answer 7

true`

Question 8

Sometimes we often get diarrahea, and vomiting they are characteristics of pathogen that have taken this portal entry

Answer 8

gastrointestinal tract

Question 9

describe the gastrointestinal tract:

characteristics

Answer 9

germs enter in food or water
most are destroyed by the acid of the stomach or the bile of intestine
some such as vibrio cholerae can survive these conditions

Question 10

rather breathe air in, through the ingestion of food and water
- this means that infectious agents will need to be represent within the food and water
-if you cook food properly, sterile the water, wash your apple properly, refrigerate properly

the likehood of____ being infected is reduced

Answer 10

this the example of gastrointestinal tract

Question 11

this is the same tract in males because of the fact that uretha is being used

Answer 11

genitourinary tract

Question 12

describe the characteristics of genitourinary tract

Answer 12

sexually transmitted infections
some pathogens require a broken mucous membrane
for example : a cut or micro-abrasion

other organisms can penetrate unbroken membranes

conjuctiva: the membrane covering the eye

Question 13

what does conjuctiva

Answer 13

the membrane covering the eye

Question 14

the membrane covering the eye

Answer 14

conjuctiva

Question 15

can you expand on the term “cut or microabrasion”

Answer 15

normal intact barrier is not something they can bypast- but if they are natural problems they can basically weasle there way in that

Question 16

inflammation of the covering of the eye sharing droplets, towel despite the fact that anatomy of the eye is perfectly intact

Answer 16

conjuctiva

Question 17

describe how microorganisms enter a host
skin

Answer 17

unbroken skin is impenetrable by most microbes
- some microbes can gain access through hair follicles
-other microorganisms require a wound for entry
-some fungi grow on the skin, not needing to enter through skin breaches

Question 18

true or false.
skin does not have the microorganisms past, because it is very strong

Answer 18

true

Question 19

true or false.
60 layers of epithelium part of your epidemic, organisms have challenging time because of the tight junctions between them

Answer 19

true

Question 20

sebaceous gland produces

Answer 20

sebum oil

Question 21

oil is going to be _____ it’s waxy, not penetrable for water, any bugs can feed in order to facilitate in reproduction

Answer 21

hydrophobic

Question 22

describe what “some fungi grow on the skin itself, not needing to enter through skin breaches

Answer 22

opening can allow to get further infection fungi actually have the capacity to grow on the surface of the skin (athelete’s foot)- ringworm right in the surface (that is fungus)

Question 23

the fact that fungus is eukaryotic it is not ideal for oral antibiotic , rather treat with cream, so you are only putting it on top of the structure

Answer 23

tinea

Question 24

pokes all the way through a defensive layer, and inoculates the tissues underneath

Answer 24

parental route

Question 25

describe what parenteral route:

Answer 25

microbes deposited directly into tissues when skin or membranes are broken example : a tick bite can introduce bacteria into the host, lyme disease example : intravenous injection with a contaminated syringe, HIV

Question 26

parenteral therapy as oppose to oral therapy and put them into your mouth helps you deal with antibiotics that cannot cross the line of stomach

Answer 26

intervenous

Question 27

true or false. It is not just the quantity, have to consider the bacteria itself

Answer 27

true

Question 28

the number of microbes introduced is important

Answer 28

-if two microbes enter the body immune system with fight them off easily and prevent disease -the likelihood of disease occurring increases with the number of microbes introduced increases

Question 29

The virulence of microbe may be expressed numerically :

Answer 29

i) infectious dose 2)potency of a toxin

Question 30

the number tells you the danger, allows us to recognize how worse this bug to the other bug just given in the example

Answer 30

infectious dose

Question 31

***AGAIN just because something come inside your body, does not mean you are infected***

Question 32

describe what infectious dose mean

Answer 32

this is the amount of bacteria required to cause disease 50% of the population

Question 33

example of infectious dose : bacillus anthracis -enters through a cut in a skin in the ID50 is -enters via inhalation the ID50 is -enters via ingestion the ID50

Answer 33

10-20 endospores 10,000-20,000 endospores 250,000-1,000,000 endospores

Question 34

ID50 is referring to what?

Answer 34

referring to how many organisms need to come in via initial inoculation in order to come in infection

Question 35

this allows us to recognize how worse this bug is to the other bug.

Answer 35

infectious dose

Question 36

Describe what potency of a toxin:

Answer 36

is something that's able to kill -expressed as the lethal dose -the LD50 kills 50% of the infected population

Question 37

mechanisms of pathogenicity 1) adherence

Answer 37

surface molecules that allow a pathogen to stick to the surface they often stick to specific receptors on the host cell surface

Question 38

mechanisms of pathogenecity of adherence name some examples

Answer 38

example : fimbriae or glycocalyx of abcteria example : viral proteins that allow adherence to specific host cell proteins

Question 39

analogy: could be like me sticking my key to the door - suction cup to the window

Answer 39

adherance

Question 40

mechanisms of pathogenicity: invasiveness

Answer 40

the ability of a pathogen to invade and multiply in healthy tissues - there are two types of molecules to promote invasiveness they are extracellular enzymes invasins

Question 41

enzymes that cut things ( outside ) have the opportunity to act :

Answer 41

extracellular enzymes (exoenzymes)

Question 42

describe the characteristics of extracellular enzymes (exoenzymes):

Answer 42

these enzymes erode the surface of host cells and damage tissues i) hemolysin : destroys red blood cells ii)fibrinolysis: degrades fibrin coats iii) collagenase : degrades connective tissues iv) cogulase : promotes blood coats around the bacterial cell

Question 43

true or false . extracellular enzymes (exoenzymes) products of degradation are used as a source of food and to protect the microbe form host defenses

Answer 43

true

Question 44

describe invasins : membranes becomes flexible due to cytoskeleton rearrangment

Answer 44

surface proteins that cause the rearrangments of the host cell cytoskeleteon the forces the host cell to take in the bacterium the bacterial cell is protected from the host defenses inside of the cell

Question 45

gets released in the outside and comes in the red blood cell , the outcome is the red blood cell will lysis

Answer 45

hemolysin

Question 46

done in your body to keep the bacteria from spreading, they are going to be trapped if they are able to produce _______ cause clot to dissolve then organism can reach other location

Answer 46

fibrinolysin

Question 47

degrades connective tissue, specific for cutting collagen

Answer 47

collagenase

Question 48

____ is the most abundant tissue- it will literally cut

Answer 48

collagen

Question 49

Describe what coagulase mean:

Answer 49

promotes blood clots around the bacterial cell`

Question 50

rather than breaking the form clots you made , it forces blood formation- he is inside the clot-immune system cannot see him-outcome he is protective

Answer 50

coagulase

Question 51

mechanisms of pathogenicity: Bacterial Toxins: define what toxin mean define what toxoid mean

Answer 51

Toxin: is a poisonous substance produced by a microorganism Toxoids can be used as a vaccine ex : DTaP vaccine consist of 3 toxoids : diptheria, pertussis, tetanus

Question 52

Bacterial toxins: Exotoxins: give an example

Answer 52

These are toxins which are secreted from the bacteria they are heat sensitive they can be extremely toxic: some of the most lethal substances known example : clostridium botulinum causes botulism botulism toxin: 1 mg can kill 1,000,000 guinea pigs

Question 53

this exotoxin can go into your diaphragm and cause you to die

Answer 53

clostridium botulinum

Question 54

what are the categories of exotoxins (3)

Answer 54

1.Neurotoxins 2.Enterotoxins 3.Cytotoxins

Question 55

Neurotoxins (what are the subgroups)

Answer 55

botulinum toxin tetanus toxin

Question 56

what is neurotoxin and explain what botulinum toxin

Answer 56

interfere with nerve impulses botulinum toxin : causes flaccid paralysis produced by clostridium botulinum muscles permanently relax the heart stops beating and breathing stops

Question 57

what does tetanus toxin mean:

Answer 57

causes rigid paralysis produced by clostridum tetani uncountable muscle contraction (spasms) : results in lockjaw death usually occurs due to spasms of the respiratory muscles

Question 58

stays relax and no room to expand

Answer 58

flaccid paralysis

Question 59

same idea of botulinum toxin but opposite effect do not have the capacity to relax muscle collectively a disorder we call lockjaw die of suffocation because the respiratory is locked

Answer 59

tetanus toxin

Question 60

describe the characteristics of enterotoxins

Answer 60

interfere with salt absorption in the small intestine - to counteract the high salt concentration in the intestine the cells pump out water -causes watery disrrhea example) montezumas revenge (E.coli), cholera (vibrio cholera)

Question 61

describe what cytotoxins means

Answer 61

kill cells these interfere with protein synthesis, killing all types of cells example : diphtheria toxin causes respiratory illness

Question 62

part of the outer membrane of gram negative bacteria lipopolysaccharide (LPS)

Answer 62

endotoxin

Question 63

name some characteristics of endotoxins

Answer 63

does not cause any problems when it is embedded in the membrane endotoxin (LPS) is released when the bacterium dies resulting in worsening of symptoms can cause fever ,hemorrhaging, and shock (sudden decrease in blood pressure)

Question 64

True or false. Endotoxin is not as potent as exotoxin and much more is needed to cause symptoms

Answer 64

true

Question 65

what would be an example of endotoxin? and describe the characteristics along with it

Answer 65

salmonellosis (salmonella enterica) food poisoning due to millions of dead bacteria the symptoms are causes by the endotoxin antibiotic treatment may do more harm than good

Question 66

___ can do more harm than good because it aggressively kill negative bugs releasing lots of endotoxin quickly

Answer 66

antibiotic

Question 67

gram negative systemic infection can be best treated with what type of antibiotics and why?

Answer 67

bacteriostatic antibiotics, because it holds the number constant from replicating and immune system can clean up the mess more gently

Question 68

comparing endotoxins and exotoxins distinguish what the differences are between the two

Answer 68

exotoxins: Proteins released outside of the cell extremely toxic and often lthal endototoxins: lipopolysaccharides (LPS) only released when bacteria dies not as toxic , usually not lethal

Question 69

this is attached to the outside membrane and only gets released when it dies, and toxin portion is the lipid A or the L in the LPS.What is it referred to as?

Answer 69

endotoxin

Question 70

Viral infections are ...

Answer 70

mechanisms for evading defenses: viruses invade and grow inside of the cells components of the immune system cannot reach them

Question 71

visible effects of vital infection and disruption of cell processes

Answer 71

cytopathic effects

Question 72

what is an example of cytopathic effect

Answer 72

herpex simplex virus stops host cell division

Question 73

what is HSV I HSV II

Answer 73

HSV I = oral herpes HSV II= genital herpes

Question 74

name more characteristics of cytopathic effects:

Answer 74

destruction of intracellular structures occurs the virus can form inclusion bodies which consists of viral parts (capsomeres) giant cell formation : several infected cells fuse to form one giant cell example : caused by colds infection often results in host cell death

Question 75

describe what destruction of intracellular structures mean during cytopathic effects?

Answer 75

mitochondrial destruction, ribosomes, eukaryotic cell

Question 76

if it's a naked virus lysis of release envelope happens eventually

Answer 76

often results in host cell death