Chap8- General Principles Flashcards
1
Q
What is a prion
A
abnormally folded host protein PrP
2
Q
What diseases are caused by prions
A
kuru- spongiform encephalopathie
Creutzfeldt-Jakob disease
Bovine spongiform encephalopathy (mad cow)
variant CJD- from infected bovine
3
Q
How do prions cause disease
A
undergo a conformational change that is resistant to proteases
the resitance PrP then convert normal PrPs
4
Q
how can CJD be transmitted
A
iatrogenically, surgery, organ transplant, blood transfusion
5
Q
What is a virus
A
obligate intracell organism that need host machinery
have genome in a capsid and sometimes encased in lipid membrane
6
Q
Under a light microscope how can you identify a virsu
A
inclusion bodies
7
Q
What are the common viruses with inclusion bodies
A
cytomegalovirus
herpes
smallpox and rabies
8
Q
what is a latent infection
A
nonreplicating form of a virus
9
Q
What are bacteria
A
prokaryotes, do not have membrane bound organelles
gram + have single outside layer
gram - have 2 thin lipid bilayers
10
Q
what are pili on bacteria used for
A
attach to host cells or ECM
11
Q
Describe staining of Staph aureus
A
gram + cocci in clusters- degenerating neutrophils
12
Q
describe staining of Strep. pneumoniae
A
gram + elongated cocci in pairs and short chains
13
Q
describe staining of clostridia species
A
gram + and -
although tru gram +
14
Q
What are common gram - rod bacteria
A
E coli, klebsiella pneumoniae
15
Q
What is the most common seem gram - diplococci
A
neisseria gonorrhea
16
Q
What bacteria causes lyme disease meningoencephalitis
A
spirochete Borrelia burgdorferi
17
Q
What bacterium contributes to dental plaque
A
strep mutans
18
Q
what are facultative intracellular bacteria
A
can survive and replicate outside or inside host
19
Q
what are obligate intracellular bacteria
A
need the host to survive
20
Q
are chlamydia and Ricketssia, obligate or facultative
A
obligate because rely on ATP for energy source
21
Q
What is the most frequent infection that leads to female sterility
A
chlamydia trachomatis
scarring fallopian tubes and blindness via conjunctivitis
22
Q
How does Ricketssia cause damage
A
injures endothelial cells and causes hemorrhagic vasculitis and sometimes CNS
23
Q
Rocky Mountain spotted fever and epidemic typhus are examples of what
A
Ricketssia family
24
Q
What bacteria are the tiniest free living organisms known
A
mycoplasma organisms
25
What are fungi
eukaryotes with thick, chitin cell walls with ergosterol-containing membranes
26
What are the 2 shapes of fungi
rounded yeast cells or slender filamentous hyphae
27
describe the types of hyphae fungi charactersitics
septate(with cell walls) or aseptate
28
Describe fungi thermal dimorphism
hyphal forms at room temp then yeast at body temp
29
What are conidia
asexual spores from fungi
30
Describe the superficial fungi
dematophytes that are referred to as tinea
31
what are examples of fungal species that invade subcut
sporothrichosis
| tropical mycoses
32
Describe the clinical features of oportunistic infections in immunocompromised patients
tissue necrosis, hemorrhage and vascular occlusion
33
What opportunistic infection is seen in AIDS patients
Pneumocystis jiroveci
34
What are protozoa
single celled mobile eukaryotes
35
What is the protozoa in RBC? in Macrophages?
RBC plasmodium
| macrophages leishmania
36
What are the most common intestinal protozoans?
| What are their 2 forms
entamoeba histolytica
giardia lamblia
motile trophozoites that attach to intestinal epithelial wall
immobile cysts that are R to stomach acids and infectious when ingested
37
What type of organism is trichomonas vaginalis
protozoa
38
How are the blood borne protozoans trasnmitted
insect vectors
39
How is toxoplasma gondii acquired
contact with oocyst shedding kittens or by eating cyst-ridden undercooked meat
40
What are helminthes
highly differentiated multicellular organisms with complex life cycles
41
What are the differences of ascaris, toxocara and echinococcus species of helminthes
ascaris lumbricoides is adult
toxocara canis is immature
echinococcus species are asexual larval forms
42
is 10 hookworms a problem
rarely but 100 can cause anemia
43
What is the mode of disease caused by schistsomiasis
disease is from inflammatory response to eggs or larvae rather than to the adults
44
What are ectoparasites
insects: lice, bedbugs, fleas or arachnids: mites, ticks and spiders
45
What is typically found at the site of a ectoparasite bite
lymphocytes, macrophages, eosinphils
46
What bacteria can be seen in H&E stains
the inclusion body forming bacteria, Cadida and mucor fungi, most protozoans and all helminthes
47
Where are organisms best visualized
edge of a lesion not the center
48
Acid Fast staining is used to visualize what
mycobacteria and nocardiae
49
silver stains are used to visualize what
fungi, legionella and penumocystis
50
periodic acid shiff is used to visualize what
fungi and amebae
51
mucicarmine stain is used to visualize what
cryptococcie
52
giemsa stain is used to visualize what
campylobacteria and leishmaniae, malaria parasites
53
What marker is used Dx shortly after onset symptoms
IgM Ab
54
What rise in titer is considered Dx
4X
55
what is used for Dx of gonorrhea and chlamydia, TB and herpes encephalitis
PCR
56
in detecting herpes is a PCR of CSF more sensitive or a viral culture of CSF
the PCR
57
For chalmydia do you want normal culture or necleic acid tests as well
nucleic acid detects 10-30% more
58
What does ebola virus cause
epidemic ebola hemorrhagic feer
59
what does hantaan virus cause
hemorrhagic fever with renal syndrome
60
what does campylobacter jejuni cause
enteritis
61
what does HTLV-1 cause
T cell lymphoma or leukemia, HTLV- assoc myelopathy
62
What does S.aureus cause
Toxic shock syndrome
63
what does E coli cause
hemorrhagic colitis, hemolytic-uremic syndrome
64
What does Borrrelia burgdorferi cause
lyme disease
65
What does helicobacter pylori cause
gastric ulcers
66
what does Hep E cause
enterically transmitted hepatitis
67
what does Hep C cause
Hep C
68
When was vibrio cholerae detected
1992 as new choler straing
69
what causes cat scratch disease
bartonella henselae
70
what is kaposi sarcoma assoc with
AIDs patients HHV-8
71
When was west nile virus identified
1999
72
When was SARS identified and what is its manifestation
2003
| coronavirus causing severe acute respiratory syndrome
73
What species have acquired antibiotic resistance
Mycobacterium tuberculosis, Neisseria gonorrhoeae, S.aureus, Enterococcus faecium
74
What are catergory A bioterism organisms
```
Anthrax- bacillus anthracis
Botulism- Clostridium botulinum toxin
Plague- yersinia pestis
smallpox- variolla major virus
tularemia
viral hemorrhagic fevers
```
75
What are catergory B bioterism organisms
```
Brucellosis, epsilon toxin-Clos perfringens
food safety(salmoneela, e coli)
glanders
meliodosis
staph enterotoxin B
Ricin toxin (castor beans)
typhus fever
viral encephalitis
```
76
What are category C bioterism organisms
emerging infectious disease threats such as Nipah and Hantavirus
77
What is common in the cat A bioterism organisms
need small dosages to cause large infection
| aerosolize
78
What are signs of smallpox infection
7-17 days have high fever, HA and backache
| then rash on mouth and pharynx, face and forearms that continues to spread
79
What components of skin are part of our immunity
dense keratinized outer layer with pH 5.5 and the FA inhibit microorganism growth
80
What organism can enter unbroken skin and how
Schistosoma larvae from freshwater snails via collagenase and elastases
81
What are the GI defenses against microorganisms
```
acidic gastric secretions
layer of viscous mucus
pancreatic enzymes and bile dtergents
mucosal defensins
flora
secreted IgA Ab
```
82
why are shigella and giardia cysts so relentless on the GI track
resistant to gastric acid
83
What make the IgA Ab in GI
MALT mucous associated lymphoid tissues covered by M cells that transport the Ag
84
What weakens our GI system
low gastric acidity by Ab that alter normal flora
| Resistant nonenveloped viruses
85
how do staphylococcal strains cause GI disease without bacterial multiplication
powerful enterotoxins on the food
86
What is the mech of V cholerae and E coli in the GI
release exotoxins that cause gut to secrete large volumes of fluid
87
what is the mech of shigella, salmonella and campylobacter in the gut
invade and damage intestinal mucosa and lamina propria causing ulceration, inflammation and hermorrhage
88
What is the mech of salmonella typhi in GI
enters through peyer patches and mesenteric lymph into blood stream resulting in systemic infection
89
What tapeworm clinically apppears to cause pernicious anemia
Diphyllobothrium datum from depleting host of B12
90
How do respiratory pathogens escape innate mech
attach to epithelial cells in lower respiratory tract and pharynx
or impair ciliary activity
91
qHow do influenza viruses attack respiratory system
have hemagglutinin proteins that project from surface protein and then neuroaminidase which cleave it and allow rvirus to enter host cell
92
what pathogens inhibit ciliary mech of airways
haemophilus influenza and Bordetella pertussis
93
what lung infections are chemotherapy patients most at risk for
Aspergillus species
94
Why are women more prone to urinary infections
shorter urethra
95
what happens if UTI retrograde to the bladder
can go further anc cause chronic polynephritis
96
what is the initial microbial spread
tissue planes of least resistance and sites drained by lymph
97
What pathogens can leukocytes carry
herpes, HIV, mycobacteria and leishmania and toxoplasma
98
What pathogens are carried on RBC
viruses- colorado tick fever virus
| parasites- plasmodium and babesia
99
what are the manifestations os serious pathogenic insult
fever, low BP, sepsis
100
poliovirus enters via intestine but spread where
kills motor neurons
101
shistosoma mansoni parasites penetrate skin but damage ehere
localize in blood and mesentery damaging liver and intestine
102
Where does varicella zoster virus hide latently until activated
in the DRG then on activation travels on nerves to cause shingles
103
when can there be transmission of treponemas in utero
late second trimester and causes severe fetal osetochondritis and periostitis
104
What infections can occur through maternal milk
CMV, HBV, Human T cell leukemia virus 1
105
What pathogens are usually spread via respiration
viruses and bacteria
106
what pathogens are spread fecal-orally
viruses helminths
107
What are some water-borne viruses
Hep A and E
poliovirus
rotavirus
108
what pathogens are spread mainly through saliva
EBV, CMV, mumps
109
what pathogens are spread by sexual transmission
viruses: HPV, HSV, HBV, HIV,
bacteria: T. pallidum, N. gonorrhoeae, C.trachomatis
fungi: Candida
protozoa: Trichomonas
Arthropods: Phthirus pubis (crabs)
110
animal to human transmission is called what
zoonotic infections
111
What does chlamydia cause in a male? female? both?
urethritis, epididymitis, proctisis
female: urethral syndrome, cervicitis, salpingitis
both: lymphogranuloma venerum
112
What infections causes ectopic pregnancies in women
Neisseria gonorrhoeae
113
Are viruses or bacterial infections more harmful to a fetus
viruses
114
What are nosocomial infections
infections acquired at the hospital
115
what is the most common cause of hospital acquired infections
hands of healthcare workers
116
What is the main innate immune cell
NK
117
what pathogens are known to stay latent until immune system is down
EBV and TB
118
what are the mech in which microorganisms cause disease
contact or enter host and directly cause cell death
release toxins and kill cells or enzymes that slowly degrade
induce host immune responses causing additional damage
119
What is the definition of tropism
predilection fo viruses to infect certain cells
120
what are the factors for tropism
- expression of host cell R for the virus
- presence of cell transcription factors that recognize viral enhancer and promoter sequences
- anatomic barriers
- local temp, pH and host defenses
121
What does HIV use to enter host
its glycoprotein gp120 binds CD4 T cells via CXCR4 and CCR5
122
How does EBV get into cells
its envelop eglycoprotein gp350 cinds complement R 2 (CR2/CD21) on B cells
123
Why do rhinoviruses infect upper respiratory tract only
replicate optimally at lower temp in URtract
124
What are the direct cytopathic effects of viruses
some viruses kill cells by preventing synthesis of host macromolecules(DNA RNA) by enzymes and toxic proteins or inducing apoptosis
125
What is the primary cell defense for viruses
CTLs
126
Bacterial damage to host depends on what
ability to adhere and enter/invade or deliver toxins
127
what is the role of plasmids and bacteriophages in infections
can pass virulent elements into other cells
| like codes for Ab-resistance
128
what are the two main types of Ab-R bacteria
vancomycin R enterococci and methicillin-R staphylococci
129
What is quorum sensing
how many bacteria can coordinate and regulate gene expression in large populations
130
How does S. aureus specifically coordinate virulence factors
secrete autoinducer peptides stimulating toxin production
131
What are biofilms
a viscouse layer of extracell polysaccharides that adhere to host and make bacteria inaccessible to immune effector mechanisms increasing their Resistance
132
What type of infections are biofilms characteristic of
bacterial endocarditis, artificial joint infections, respiratory infections in CF patients
133
What are Adhesins
bacterial surface molecules that bind host or ECM
134
What bacteria utilizes protein F and teichoic acid to bind to fibronectin
Step pyogenes( gram +)
135
What is on the strains of E colie that cause UTIs
specific P pills which binds to val(1a4) on uroepithelial cells
136
What is the main mech in which N. gonorrhoeae evades immune system
type of pili expression
137
How do bacteria enter host cells
using host immune response like coating bacteria with C3b
138
Once coated by C3b what does mycobacterium TB do
binds CR3 on macrophages and is endocytosed then blocks fusion of phagosome wtih lysosome
139
How does listeria monocytogenes spread
manipulate cell cytoskeleton
| forms pore forming protein to evade macrophage degradation
140
What are endotoxins? exotoxins?
endotoxins are components of bacterial cell
| exotoxins are secreted by bacteria
141
What is used Dx serotologically to differentiate bacteria
detection O antigen found on gram -
142
What is the response to LPS
induces cytokines and chemokines of the immune system to enhance T lymph activation
but high levels thought to have role in septic shock b/c induce TNF IL1 IL12
143
What R does LPS bind to
TLR4
144
what are types of exotoxins
enzymes, toxins that alter intracell signaling, neurotoxins, SuperAg
145
What bacteria produce A-B toxins
bacillus anthracis. V.cholerae and some strains E.coli
146
What bacteria produce neurtoxins
clostriudum botulinum and clostridium tetanii
147
How do superAg cause massive T cell activation
bind conservative portions of T cell R
148
What bacteria produce Super Ag associ with TSS
S aureus and S pyogenes
149
how can s pyogenes lead to glomerulonephritis
Ab bind Ag and form IC that deposit in the renal glomeruli
150
What is the association with pathogens and cancer
usually involve chronic inflammation
151
how do microbes evade the immune system
growth in niches that are inaccessible to host immune system
antigenic variation
R to innate immune defenses
impairment of effective T cell repsonses
152
What pathogens replicate in sites that are inaccessible to host immune
C. difficile
| S typhi in gall bladder
153
how does malaria sporozoites evade immune
enter liver cells so quickly before immune response is effective
154
What are the main mech which microbes express Ag to evade immune system
low dfidelity of viral RNA polymerases and reassortment of viral genomes create viral antigenic variation
155
What is different between serotypes of S pneumoniae
different capsular polysaccharides expressed
156
What viruses have high mutation rates
HIV and influenza
157
What viruses can undergoe genetic reassortment
influenza and rotavirus
158
what bacteria undergo genetic rearrangement
Borrelia burgdorgeri
N gonorrhoeae
Trypanosoma sp (african sleeping sickness)
Plasmodium sp. (malaria)
159
what viruses/bacteria have large diversity of serotypes
```
Rhinoviruses
strep pneumoniae (meningitis)
```
160
what are our initial defense mech on invading microbes
defensins, cathelicidins, thrombocidins
161
How does E coli cause meningitis in newborns
sialic acid which won't bind C3b so evades alternative C' pathway
162
how does salmonella reduce TLR activation
modifies LPS
163
What bacteria secrete proteases that degrade Ab
Neisseria, haemophilus and streptococcus
164
what pathogens multiply in phagocytes
bacteria: mycobacteria, listeria and legionella
fungi: cryptococcus, neoformans
protozoa: leishmania, trypanosomes, toxoplasmas
165
what viruses produce prteins that block C'
herpes and poxviruses
166
What pathway is largely inhibited by viruses
IFN JAK/STAT
167
How do microbes affect the MHC molecules
can alter them to change peptide presentation or even inhibit the NK or T cells
168
Herpes virus affects which MHC molecules
both
169
EBV effects what immune cell
B cells
170
TIV effects what immune cells
T cells, macrophages and dendritic
171
What are patients with Ab deficiency like X linked agammaglobulinemia prone to
S pneumoniae, H influenzae and S aureus
| and viral rotavirus and enteroviruses
172
Patients with t cell defects are prone to what
intracell pathogens like viruses and some parasites
173
patients with C' defects are susceptible to what
S penumoniae. H influenzae and N meningitidis
174
deficiencies in Neutrophils leads to what
increased s aureus infections and gram - bacteria
175
What are patients who receive bone marrow transplant at higher risk for
aspergillus and pseudomonas species infections
176
Patients with CF are prone to what infections
P aeruginosa
S aureus
Burkholdaria cepacia
177
What are patients with sickle cell anemia prone to
encapsulated bacteria like S pneumoniae
178
Burn victims are prone to what infection
P aeruginosa
179
What is the difference of M. TB in normal patient vs AIDS
usually causes well formed granulomas with few mycobacteria present
in AIDS causes multiple profulsey macrophages which fail to coalesce into granulomas
180
What are the 5 major patterns of tissue reaction to infection
```
Suppurative-Purulent infection
mononuclear/granulomatous
Cytopathic/cytoproliferative
Tissue necrosis
Chronic inflammation/scarring
```
181
What is suppurative infection characterized by
increased vasc permeability and leukocytic infiltration, predominately neutrophils
release of pus
182
What are the common pyogenic bacteria
gram + cocci
| gram - rods
183
What is pus formed from
neutrophils and liquefactive necrosis
184
what is the difference of pneumococci and staphylococci in lungs
pneumo causes lobar pneumonia sparing the walls
| staphylococci destroyes the walls and form abscesses that heal with scar formation
185
acute mononuclear inflammation is usually in response to what
viruses
186
what cell predominates in syphilis infection?
| HBV?
syphilis is plasma cells
| HBV is lymphocytes
187
Granulomatous inflammation is distinctive of what type of infection? give examples
infectious agents that resist eradication and stimulate strong T cell mediated immunity
M.tb, Histoplasma capsulatum, schistosome eggs
188
What type of necrosis typically happens in granulomatous inflammation
caseous
189
What is the characterization of cytopathic-cytoproliferative reactions and what class of pathogens cause it
cell necrosis or proliferation usually with few inflammatory cells
viruses
190
what are polykaryons and what viruses cause this
fusion of cells
| measles and herpes virus
191
C. perfringes causes what type of necrosis
gangrenous due to release of toxic material
192
what causes "pipe stem" fibrosis of the liver or bladder wll
schistosomal eggs
