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microbiology > chapter 11 mechanisms of pathogenicity (diana's version) > Flashcards

chapter 11 mechanisms of pathogenicity (diana's version) Flashcards

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Biology 101 flashcards
1
Q

how do micoorganisms enter a host

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

A

how an organism can makes us sick

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2
Q

true or false.

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

A

True

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3
Q

True or false.

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

A

true

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4
Q

How do microorganisms enter a host ?
name the three

A

1.Mucous membranes
2.Skin
3.Parenteral Route

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5
Q

Mucous membranes :
what are the (3) subgroups

A

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

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6
Q

Respiratory Tract:

A

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

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7
Q

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

A

true`

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8
Q

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

A

gastrointestinal tract

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9
Q

describe the gastrointestinal tract:

characteristics

A

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

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10
Q

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

A

this the example of gastrointestinal tract

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11
Q

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

A

genitourinary tract

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12
Q

describe the characteristics of genitourinary tract

A

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

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13
Q

what does conjuctiva

A

the membrane covering the eye

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14
Q

the membrane covering the eye

A

conjuctiva

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15
Q

can you expand on the term “cut or microabrasion”

A

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

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16
Q

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

A

conjuctiva

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17
Q

describe how microorganisms enter a host
skin

A

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

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18
Q

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

A

true

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19
Q

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

A

true

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20
Q

sebaceous gland produces

A

sebum oil

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21
Q

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

A

hydrophobic

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22
Q

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

A

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)

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23
Q

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

A

tinea

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24
Q

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

A

parental route

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25
Q

describe what parenteral route:

A

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

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26
Q

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

A

intervenous

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27
Q

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

A

true

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28
Q

the number of microbes introduced is important

A

-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

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29
Q

The virulence of microbe may be expressed numerically :

A

i) infectious dose
2)potency of a toxin

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30
Q

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

A

infectious dose

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31
Q

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

A
32
Q

describe what infectious dose mean

A

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

33
Q

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

A

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

34
Q

ID50 is referring to what?

A

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

35
Q

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

A

infectious dose

36
Q

Describe what potency of a toxin:

A

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

37
Q

mechanisms of pathogenicity
1) adherence

A

surface molecules that allow a pathogen to stick to the surface

they often stick to specific receptors on the host cell surface

38
Q

mechanisms of pathogenecity of adherence
name some examples

A

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

39
Q

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

A

adherance

40
Q

mechanisms of pathogenicity:
invasiveness

A

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

41
Q

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

A

extracellular enzymes (exoenzymes)

42
Q

describe the characteristics of extracellular enzymes (exoenzymes):

A

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

43
Q

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

A

true

44
Q

describe invasins :
membranes becomes flexible due to cytoskeleton rearrangment

A

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

45
Q

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

A

hemolysin

46
Q

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

A

fibrinolysin

47
Q

degrades connective tissue, specific for cutting collagen

A

collagenase

48
Q

____ is the most abundant tissue- it will literally cut

A

collagen

49
Q

Describe what coagulase mean:

A

promotes blood clots around the bacterial cell`

50
Q

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

A

coagulase

51
Q

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

A

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

52
Q

Bacterial toxins:
Exotoxins:
give an example

A

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

53
Q

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

A

clostridium botulinum

54
Q

what are the categories of exotoxins
(3)

A

1.Neurotoxins
2.Enterotoxins
3.Cytotoxins

55
Q

Neurotoxins (what are the subgroups)

A

botulinum toxin
tetanus toxin

56
Q

what is neurotoxin and explain what botulinum toxin

A

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

57
Q

what does tetanus toxin mean:

A

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

58
Q

stays relax and no room to expand

A

flaccid paralysis

59
Q

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

A

tetanus toxin

60
Q

describe the characteristics of enterotoxins

A

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)

61
Q

describe what cytotoxins means

A

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

62
Q

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

A

endotoxin

63
Q

name some characteristics of endotoxins

A

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)

64
Q

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

A

true

65
Q

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

A

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

66
Q

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

A

antibiotic

67
Q

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

A

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

68
Q

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

A

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

69
Q

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?

A

endotoxin

70
Q

Viral infections are …

A

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

71
Q

visible effects of vital infection and disruption of cell processes

A

cytopathic effects

72
Q

what is an example of cytopathic effect

A

herpex simplex virus stops host cell division

73
Q

what is HSV I
HSV II

A

HSV I = oral herpes
HSV II= genital herpes

74
Q

name more characteristics of cytopathic effects:

A

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

75
Q

describe what destruction of intracellular structures mean during cytopathic effects?

A

mitochondrial destruction, ribosomes, eukaryotic cell

76
Q

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

A

often results in host cell death

microbiology (27 decks)

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