Chapter 15 Flashcards
1
Q
pathogenicity
A
the ability to cause disease by overcoming host defensives
2
Q
virulence
A
the degree of pathogenicity
3
Q
portals of entry
A
mucous membranes
skin
parenteral route
4
Q
most pathogens gain access by
A
mucous membranes of the GI and respiratory
5
Q
unbroken skin in impenetrable to ______ microbes
A
most
6
Q
some microbes can enter the body through openings in the skin like
A
hair follicles and sweat gland ducts
7
Q
what are able to bore through intact skin
A
larvae of hookworms
8
Q
parenteral route
A
refers to microorganisms deposited directly into tissues beneath the skin or into mucous membranes that are penetrated or injured
9
Q
some examples of microorganisms that gain entry through the parenteral route
A
hepatitis viruses, tetanus and gangrene bacteria
10
Q
most pathogens have a preferred portal of entry and most of the time if these pathogens do not gain access via the preferred entry route…
A
they may not be able to cause disease
11
Q
some pathogens are able to cause disease from
A
more than one portal of entry
12
Q
ID50
A
infectious dose for 50% of a sample population
13
Q
ID50 measures ________ of a microbe
A
virulence
14
Q
LD50
A
lethal dose for 50% of a sample population
15
Q
LD50 measures ________ of a toxin
A
potency
16
Q
the likely hood of a disease ___________ as the number of pathogens increase
A
increase
17
Q
is ID50 a absolute number
A
no
18
Q
adherence (adhesion)
A
almost all pathogens attach to host tissues in a process called
19
Q
adhesions (ligands) on the pathogen and to __________ on the host cell
A
receptors
20
Q
where might adhesions (ligands) on the pathogen bind to on the host cell
A
glycocalyx, fimbriae, pili, flagella
21
Q
microbes form _________ which are communities that share nutrients
A
biofilms
22
Q
what do biofilms secrete that make them resistant
A
glycocalax
23
Q
capsules is made of what substance surrounding the cell wall
A
glycocalyx
24
Q
how do capsules increase virulence
A
enables the bacteria to resist host defenses and is able to do this by impairing or evading phagocytosis
25
one of the most notably known bacteria with capsules is
streptococcus pneumoniae
26
M protein
resists phagocytosis
27
M protein is located on the
cell surface and fimbriae
28
M protein is resistant to
heat and acid
29
does M protein increase or decrease the virulence
increae
30
what is one bacteria that has M protein
streptococcus pyogenes
31
Opa protein
allows attachment to host cells
32
when opa protein is present how do the colonies appear
opaque
33
mycolic acid
waxy lipid that resists digestion
34
what is one bacteria that has opa protein
neisseria gonorrhoeae
35
what is one bacteria that has mycolic acid
mycobacterium tuberculosis
36
coagulases
coagulate fibrinogen
37
kinases
digest fibrin clots
38
hyaluronidase
digests polysaccharides that hold cells together
39
collagenase
breaks down collagen
40
IgA proteases
destroy IgA antibodies
41
antigenic variation
pathogens alter their surface antigens
42
invasins
surface protein produced by bacteria that rearrange actin filaments of the cytoskeleton
43
invasins will cause
membrane ruffling
44
some bacteria use _____ to move from one cell to the next
actin
45
what are some bacteria that use actin
shigella and listeria
46
survival inside phagocytes must meet 1 of these requirements
- requirement for low pH in phagolysosome
- escape from phagosome before lysosomal fusion
- prevention of fusion of lysosome with phagosome
47
biofilms play a role in evading
phagocytes
48
biofilm bacteria more resistant to phagoctosis, shielded by _________ __________ _________ of biofilm
extracellular polymeric substance (EPS)
49
microorganisms can damage host cells in 4 basic ways
1. by using the hosts nutrients
2. by causing direct damage
3. by producing toxins
4. by inducing hypersensitivity reactions
50
_____ is required for most pathogenic bacteria
iron
51
siderophores
proteins secreted by pathogens that bind iron more tightly than host cells
52
some examples of direct damage
disrupts host cell function
uses hosts nutrients
produces waste products
multiplies in host cells and causes rupture
53
toxins
poisonous substances produced by microorganisms
54
toxins can produce what kind of complications
fever, cardiovascular problems, diarrhea, shock, inhibit protein synthesis, destroy blood cells and vessels, disrupt the nervous system by causing spasms
55
toxigenicity
ability of a microorganism to produce a toxin
56
toxemia
presence of a toxin in the hosts blood
57
what are 2 toxins that could be toxemia
endotoxin and exotoxin
58
intoxications
caused by the presence of a toxin not by microbial growth
59
exotoxins are produced where in bacteria
inside
60
exotoxins are then secreted to the
outside
61
exotoxins are produced as a product of
growth metabolism
62
exotoxins are proteins secreted by
gram neg and gram pos
63
exotoxins are (soluble/insoluble?) in bodily fluids; destroy host cells and inhibit metabolic functions
soluble
64
if you are sick with a bacterial infection producing exotoxins, what are producing the specific signs? bacteria or exotoxins?
exotoxins
65
are exotoxins disease specific
yes
66
antitoxins
antibodies against specific exotoxins
67
toxoids
inactivated exotoxins used in vaccines
68
exotoxins are named on basis of several characteristics
1. type of host cell that is attacked
2. the disease of which they are associated with
3. specific bacterium that produces them
69
3 types of exotoxins
1. AB toxins
2. Membrane disrupting toxins
3. superantigens
70
most exotoxins are
A-B
71
A-B toxins contain an enzyme compartment (A/B?), and a binding component (A/B?)
A, B
72
A component is
enzyme
73
B component is
binding
74
genotoxins damage DNA by causing
mutations, disrupting cell division, and leading to cancer
75
membrane disrupting toxins
lyse host cells by disrupting plasma membranes
76
leukocidins
kill phagocytic leukocytes
77
hemolysins
kill erythrocytes by forming protein channels
78
streptolysins
hemolysins produced by streptococci
79
superantigens
cause an intense immune response due to release of cytokines from host cells (T cells)
80
exotoxins are lipids or proteins
proteins
81
endotoxins are lipids or proteins
lipids
82
endotoxins are part of the
outer portion of the bacterial cell
83
endotoxins grow in what gram
gram neg
84
what is the toxic part of endotoxins
lipid A
85
lipid A is a portion of
lipopolysaccharides (LPS)
86
endotoxins are released during
bacterial multiplication
when the gram neg cell dies
87
are endotoxins disease specific
no, they all cause the same signs and symptoms no matter the species but do not produce effects to the same degree
88
endotoxins
stimulate macrophages to relesse ___________
cause ______________ ______________ ________ and/or septic shock
cytokines, disseminated intravascular coagulation (DIC)
89
what is used to test for endotoxins
limulus amebocyte lysate (LAL) assay
90
what contains amebocytes
blood of horseshoe crabs
91
amebocyte lyse in the presence of endotoxins producing a
clot
92
exotoxins bacteria source
gram pos and gram neg
93
exotoxins relation to microorganism
metabolic product of growing cell
94
exotoxins chemistry
proteins, usually with 2 parts (A and B)
95
exotoxins pharmacology effect on body
specific for a particular cell structure or function in the host (mainly affects cell functions, nerves, and GI)
96
exotoxins heat stability
unstable; can usually be destroyed at 60-80 degrees C (except staphylococcal enterotoxin)
97
exotoxins toxicity (ability to cause disease)
high
98
exotoxins fever producing
no
99
exotoxins immunology (relation to vaccines)
can be converted to toxoids to immunize against toxin; neutralized by antitoxins
100
exotoxins lethal dose
small
101
exotoxins representative diseases
gas gangrene, tetanus, botulism, scarlet fever
102
endotoxins bacterial source
gram neg
103
endotoxins relation to microorganism
present in LPS of outer membrane of cell wall and released with destruction of cell or during cell divsion
104
endotoxins chemistry
lipid portion (lipid A) of LPS of outer membrane
105
endotoxins pharmacology (effect on body)
general, such as fever, weakness, aches, and shock; all produce the same effects
106
endotoxins heat stability
stable; can withstand autoclaving (121 degrees c for 1 hour)
107
endotoxins toxicity (ability to cause disease)
low
108
endotoxins fever producing
yes
109
endotoxins immunology (relation to vaccine)
not easily neutralized by antitoxin; therefor, effective toxoids cannot be made to immunize against toxin
110
endotoxins lethal dose
considerably larger
111
endotoxins representative diseases
typhoid fever, UTI and meningococcal meningitis
112
plasmids may carry genes for
toxins, production of antibiotics, and enzymes
113
lysogenic conversion changes characteristics of a microbe due to
incorporation of a prophage
114
cytopathic effects (CPE)
visible effects of viral infection on a cell
115
do CPE vary by virus
yes
116
CPE which result in death are known as
cytosidal effects
117
CPE which result in cell damage are known as
noncytosidal effects
118
CPEs cause many issues, what are they
stopping cell synthesis
causing cell lysosomes to release enzymes
creating inclusion bodies in the cell cytoplasm
fusing cells to create a syncytium
changing host cell function or inducing chromosomal changes
inducing antigenic changes on the cell surface
loss of contact inhibition in the cell, leading to cancer
119
alpha and beta interferons are produced by
virally infected host cells
120
alpha and beta interferons protect the host cells _______________ _______ from viral infection
neighboring cells
121
what 2 ways to alpha and beta interferons protect neighboring cells
inhibit synthesis of viral proteins and host cell proteins
kill virus infected host cells by apoptosis
122
some fungal pathogens produce
toxic metabolic products
123
some chronic fungal infections can provoke an
allergic response
124
some fungal toxins are known to inhibit ______ synthesis in eukaryotic cells
protein
125
some fungi produce __________ that modify host cell membranes, allowing for attachment
proteases
126
Ergot
alkaloid toxins that cause hallucinations
127
what is the natural source of LSD
ergot
128
Alfatoxin
carcinogenic toxin produced by aspergillum
129
mycotoxins
produced by mushrooms and are neurotoxic
130
phalloidin and amanitin are potent neurotoxins produced by
death cap mushroom
131
presence of protozoa and their waste products causes
symptoms
132
protozoa avoid host defenses by
digesting cells and tissue fluids
growing in phagocytes
antigenic variation
133
helminths use ____ tissue for growth
host
134
helminths produce large parasitic masses that cause ______ ________ and bring about symptoms
cellular damage
135
some parasites are able to block _________ ____________ causing edema
lymphatic circulation
136
some algae produce a neurotoxin called
saxitoxin
137
what is an example saxitoxin
PSP
138
most common portals of exit
respiratory tract, GI tract
139
Respiratory tract portal of exit
coughing and sneezing
140
GI tract portal of exit
feces, saliva
141
Genitourinary tract portal of exit
urine, secretions from the genital
142
skin infections portal of exit
drainage from wounds
143
blood portal of exit
arthropods that bite
needles or syringes
