IID Flashcards
(97 cards)
1
Q
What do viruses lack in their structure?
A
They dont have genes that encode complete prot synth nor genes inv in metabolism or biosynth, or centromeres/telomeres
(so viral genomes must make mRNA that can be translated by HOST RIBOSOMES)
2
Q
Which type of capsids in viruses have envelope?
A
All HELICAL viruses
3
Q
How do envelope viruses leave cell?
What is in the envelope?
A
Via budding (genome buds out) Envelope has peplomers (attachment/fusion proteins eg neuraminidase etc)
4
Q
Diffs between naked viruses and enveloped viruses?
In terms of sensitivity, release from host cell, transmission, survival in GI tract, immune response)
A
- Naked are more resistant (to heat etc, are lysed from host cell, transmitted via fomites/droplets/fecal-oral, can survive in GI tract, triggers ab response in host
- Enveloped have glycoprot/phospholip/prots, are sensitive/labile, released from host cell via budding (cell survives) and lysis, droplets/secretions/organ transplant/transfusion, cant survive in GI tract, has antibody/cell med response
5
Q
There are two types of viruses based on genome, what are they?
A
DNA viruses and RNA viruses
6
Q
What are the 3 types of DNA viruses? (all icosahedral except POX)
A
double stranded
single stranded NON enveloped
and complex enveloped
7
Q
Types of double stranded dna viruses?
A
enveloped, and non-enveloped (circular and linear)
8
Q
Mnemonic for DNA viruses?
A
HHAPPPPy
9
Q
enveloped dsDNA viruses? (2)
A
HERPES & HEPADNA
10
Q
non-enveloped linear dsDNA virus?
non-enveloped circular dsDNA virus? (2)
A
LINEAR nonenv dsdna: ADENOVIRUS
CIRCULAR nonenv dsdna: POLYOMA & PAPILLOMA
11
Q
Example of an ss non-enveloped DNA virus?
Example of a complex enveloped?
A
ssDNA nonenveloped: PARVO
complex enveloped dna: POX
12
Q
RNA virus types? 3
A
SINGLE STRANDED + SENSE
SINGLE STRANDED - SENSE
DOUBLE STRANDED
13
Q
(+) stranded RNA virus mnemonic?
A
CALCified old emperor PICO, drinks CORONA, in a TOGA while eating RETRO FLAVAS
14
Q
Types of single stranded + sense RNA viruses and subtypes
A
ENVELOPED and NONENVELOPED
ENVELOPED composed of icosahdral and helical
15
Q
Ss - sense RNA viruses are what type
A
enveloped and helical
16
Q
DS rna viruses are what type
A
NONENVELOPED AND ICOSAHDERAL
17
Q
Mnemonic for - SENSE RNA VIRUSES
A
Old Petes RABID dog FILO fights BUNYon in the ARENA
18
Q
nonenv ss + sense RNA viruses?
A
icosahedral only
PICO
CALC
19
Q
enveloped ss + sense RNA viruses?
A
helical: CORONA
icos: TOGA, FLAVA, RETRO
20
Q
ss - sense rna viruses
A
enveloped and helical only ORTHO PARA RHABDO FILO BUNYA ARENA
21
Q
double stranded - sense RNA virus
A
REO
22
Q
What are the 6 steps in viral replication?
A
Adsorption Penetration Uncoating Synthesis Assembly Release
23
Q
What is a susceptible vs permissive cell
A
cell can receive virus (resistant is no receptor for virus)
permissive means cell can replicate virus
(must be sus and perm to take up virus and replicate it)
-Also need accessibility
24
Q
What types of penetration do naked vs enveloped viruses do?
A
naked: direct penetration
enveloped: endocytosis or fusion
25
*** viral structure class and repl noteset pages 8 and 9
go over
26
Antigenic DRIFT vs SHIFT
DRIFT: mutations adapt to changed conditions
SHIFT: genetic recomb between related viruses, reassortment during mixed infxn leading to 2 diff strains (eg flu)
27
Antigenic DRIFT vs SHIFT
DRIFT: mutations adapt to changed conditions, making new strain
SHIFT: genetic recomb between related viruses, reassortment during mixed infxn leading to 2 diff strains (eg flu) (2 strains from 1 host combine into new strain u arent immune to)
28
Passive vs active immunity?
Passive: ab's from another
Active: produce own ab's
29
Easy vs difficult disease to eradicate?
```
polio easy, smallpox easy
ebola difficult (many animal reservoirs)
```
30
How long do you want to wait to give booster?
After B and T cell expansion diminishes so memo response can occur
31
LIVE attenuated vaccine? MOST common way to make it?
virus can be transmitted but not virulent
Most common way to make it is passage of virus from unnatural host (take virus, put in animal where it gains mutations, now put back into human bc nontoxic)
32
What is a subunit virus and examples
give small amt of antigen
Tetanus: give one subunit, the toxoid
Pertussis: several antigens etc
33
Whole inactivated virus
cant spread, heat etc inactivated
34
What is the R0 in herd immunity>
R0 is # of ppl a single person can infect, when this is HIGH the threshold % needed to maintain herd immunity is high! (eg measles)
35
Types of virus serological dx? Adv? disadv?
```
Immunoblot assay
ELISA )IgM IgG or ag)
Hemagglutinin
Adv: fast sensitive, specific
disadv: false pos or neg, presence of ab means previous infection but cant indicate if its new infx
```
36
Which virus dx technique is the "gold standard"?
| Adv and disadv?
Virus isolation!
Adv: no false pos, sensitive and sepcific etc
Disadv: not all viruses replicate inlab, req lab personnel, slower, need good conditions etc
37
3 Methods of direct detection in Dx of viruses?
Immunostaining
Histochem
Electron micro
PCR/hybridization/sequencing
38
What are CPEs?
cytopatho effects in viruses, so signs where we can tell a virus is at work (eg necrosis, apoptosis etc)
39
What is serology, and what does increased IgM vs IgG levels indicate
Serology is detecting antibody levels in titers
Incr in IgM is first time ab is seeing infxn
Incr IgG is body has faced it before
40
ELISA
diff wells with diff antigens, released ab's into wells that bind ag, add enz and substrate to wells and rate of color formation is prop to specific ab in it
41
Hemagglutination
see how virus binds to RBCs then trying to hinbiit with abs
| -w/o virus, RBCs sink and form button, but when you add virus, cells hemagglutinize and dont form button
42
Number one route for virus?
mucosa!
43
how can virus infect GI
thru M cells between enterocytes (have immune cells in patches so if they detect smth will cause inflam)
44
Which viruses cause conjunctiva
HSV, adeno, CMV
45
"tropism" or -tropic in virus indicates?
what tissues it likes to infect, eg pantropic or enterotropic
46
Diff forms of viremia in HEMATOGENOUS (blood) viruses
active: virus being actively replicated and spreading thru blood
passive: not repl at site of entry, but from passive mosquito inoculation etc
primary: progeny rel after initial infxn at first site
secondary: virus spreads to other tissues, leads to huge incr in virus, (impt in transplants)
47
how can virus move thru blood
bind to endoth cell replicate and burst out
transycotis fusing and released
infect monocytes and use them to travel
48
how do neural viruses travel
against electrical impulses w kinsesins and infect cell body
49
types of neural viruses
neurotropic infect neural cells from periph site
neuroinvasive can enter CNS after periph infx (eg mumps gets to CNS but MILD so low virulence)
neurovirulent can cause neuro disease (eg HSV, but low neuroinvasiveness bc rarely enters CNS but lethal if it does)
Rabies is high for both
50
What is the main immune thing viruses must evade?
Type 1 Interferons (innate)
virus blocks this with microRNA that decreases NK cells from finding them, or neutralize w molecs
-Also must evade CD8 binding and killing (messes with apop path or TAP or MHC I etc, or viruses change shape of antibody opsonin epitope)
51
What is directional release (a physical barrier to virus spread) for?
flu and measles have apical rel so can go into host via feces (local spread)
others have basolateral release (from immune defenses in lumen to BL side of tissue, sys spread)
52
Latent vs persistant virus (acute is flu)
latent eg HSV, persistent pathogenic is HIV
53
what do miRNAs (micro rnas) do
inv in viral virulence, regulate gene expr, certain ones may be req for viral repl
54
Viroporins?
Syncytium formation (by enveloped viruses_
(virulence)
viroporins mess up cell memb
| syncytium fuses cell with neighboring cells
55
Fungi are dimorphi (gives it ability to adapt to diff conds)
Where and what temp do they present as molds?
Where and what temp do they present as molds
mold at 25C eg in nature etc
| yeast at 37C in vivo/vitro (can elongate to form psudohyphy)
56
Fungi are thermally dimorphic (gives it ability to adapt to diff conds)
Where and what temp do they present as molds?
Where and what temp do they present as molds
mold at 25C eg in nature etc
| yeast at 37C in vivo/vitro (can elongate to form psudohyphy)
57
What types of fungi are impt clinically?
ace
| ace spores are conidia
58
fungal cell wall contains?
| cell memb contains?
wall:
mannoportein
glucans
chitin
memb: ergesterol
59
Mycotoxicoses
| Mycoses
accidental or recreational ingestion of myco toxin
(eg aflatoxin B1 produced by Aspergillus flavus)
mycoses: fungal infxn caused by true pathogens
60
Opportunistic pathogens
no significant virulence traits so host defenses must be impaired, or use of broad spectrum antibiotics for long time or radiation etc
61
examples of opportunistic pathogesn
candidia (eg yeast infx), aspergillus
62
types of fungal infxn
Superficial (strat corn)
cutaneous (keratinized tissue)
subcut (usua traumatic implantation)
systemic: inhalation
63
Opportunistic pathogens and sx
CANDIDIASIS: superficial or sys, yeast
PCP (pneumocystic), lung gissue has foamy eosinophilic exudate, pulm, AIDS defining!
(also cryptococcis CNS infxn meningitis, and aspergillosis causing toxicosis)
64
Lab dx of fungi? (microscopic findings)
KOH of scales
wood lamp
India ink to analyze CSF ofr cryptococcal mening
Geimsa etc
65
other fungi lab dx
histologigy (GMS or PAS)
lab cultures
serology (antibodies, latex agglutinatino)
PCR (amplify fungal dna)
66
5 main mycosal treatments
Polyenes (Aphotericin B and nystatin)
Azoles (imidazoles like miconizole, ad triazole derivs) BLOCK ERGOSTEROL SYNTH
5-flurocytosine (FLUCY, BLOCKS DNA SYNTH)
Griseofulvin (blocks MICROTUBULE ACTIVITY)
Echinocandins (inhibit 1-3 GLUCAN SYNTH IN FUNGAL CELL WALL)
67
SUPERFICIAL MYCOSES LIST
Pityriasis (tinea) versicolor from M FURFUR
Tinea nigra from H WERNECKII
Black piedra from PIEDRAIA H
White piedra from T BEIGELII
68
```
Pityriasis (tinea) versicolor
Sx
Tx
Yeast type
Env
Slides
```
M FURFUR
scaly patches, pigmented,
tx with miconazole (block erg synth) or Tinactin/tolfnafatate cream in a few weeks, cosmetic
lipophilic yeast so in young adults and younger
Warm climates
spaghetti and meatball slide (fatty media)
69
```
Tinea Nigra
Sx
slides
where is infxn
lesion type
tx
```
H WERNECKIA
dermaticaeous, produces melanin macule, macular brown or black lesions on soles and feet, flat
tx with MICONAZOLE (a topical fungicide that blocks erg synth)
70
Black and white piedra sx and tx
black: PIEDRAIA H: grow on hair shaft black nodules, Tx with dandruff shampoo better hygeine and miconazole
White piedra is TRICHOSPORAN BEIGLII, soft light pasty nodules along hair shaft, same tx
ASSOCIATED with trichosporonosis
71
3 etiological agents in CUTANEOUS FUNGUS DERMATOPHYTES (tinea, ringworm)
TRICHOPHYTON microconidia
MICORSPORUM: thicc macro
EPIDERMOPHYTON FLOCCOSUM: club shaped thin macro
cell mediated immunity impt in all these thing, high ab titers means immune sys didnt clear it
72
What is a dermatophytid rxn
HS where circ fungal antigen causes effect remote from fungal entry (papules etc but wont see fungal cells at entry)
73
dermatophyte conidia cells
use to ID fungus esp in cutaneous, almond shape and multinucl, can be macro or micro
74
4 CUTANEOUS DERMATOPHYTES
E floccosum
M canis
T rubrum
T mentagrophytes
75
E floccosum
like yellow fungus club shaped smooth walls
NO MICROCONS
neg hair perf, urease pos
76
What is hair perforation test
take sample and put with scale and see if organism eats it cuz some do and some dont
77
Microsporum canis
cream yellow colony growth
| hair and urease pos, scalp and skin, usu found in DOGS (ringworm)
78
Trichophyton rubrum
RED in dish, both macros and micros, neg hair perf and urease
79
Trichophyton mentagrophytes
both macro and micro
SPIRAL shaped hyphae
pos hair perf
80
Kerion lesion on face
| onchomyosis
kerion is infxn of hair follicles that allow bacteria to grow so treat with anti to both
onchomyosis is foot infxn esp nail, no good oral antibios
look at wood lamp
81
3 SUBCUTANEOUS MYCOSIS
sporotrichosis
chromoblastomycosis
mycetoma
82
Sporotrichosis (SPOROTHRIX agent)
nodular lesions and lymph, entry can be from thorn implantaion eg ROSE HANDLERS DISEASE
(bump, along lymph lines)
dx cigar shaped yeast cell, pcr, culture
Tx: Potassium iodide, ampho b for relapse, 5-fluor
83
Chromoblastomycosis
Yeast phase
etio eagent is dematiaceaus fungi (pigmented), seen in TROPICS
cauliflower appearing lesions
KOH prep see medlar bodies (look like pennies)
Tx cryotherapy or lesion removal
84
Mycetoma
can be fungal OR bacterial!
| draining sinuses or pus, ooze (know if fungal or bacterial to det tx)
85
API
microbe test, bacteria added to wells and incubated and ph and color changes (strip tells bacteria)
ANALYTIC PROFILE INDEX
86
Lateral flow immunoassay
sample migrates down sample til it encoutners ab's spec for virus being tested, display purple line which indicates virus (also control region)
87
What tests can u use to detect specific ab
ELISA or immunoblot
Plaque-reducing neutralization titers
PCR
88
Latex agglutination test
can look for ag specific antibodies (conj antigen specific to certain virus to latex beads), if there are abs that are spec to latex ag, will agglutinate
can also look for spec antigen: coat latex beads with ab's specific to an ANTIGEN we are looking for in pt
89
SENSITIVITY
prob that infected indiv will actually test +
TP/TP+FN (T always on TOP)
(denom is prevalance)
90
SPECIFICITY
prob that ppl without disease will have NEGATIVE test
| TN/TN+FP
91
5 TYPES OF HOSTS
definitive: hosts sexual stage of parasite
intermediate: hosts asexual stage
paratenic host: hosts dormant parasite
principal stage: best for parasite
incidental host: nto suual host but still works
92
anisikiasis parasite
wants to be in large marine mammal, L2 excreted and eaten by shrimp, eaten by fish, L3 larva infect marine animal that eats fish, we eat sushi
93
Entamoebia histoylytica
obligate parasite,
| eat cyst and poop out
94
Naegleria fowleri
brain eating amoeba, fac parasite, lives in ponds (clean ur neti pots)
95
Wucheriea bancroft
elephantiasis
| many asymptomatic
96
Ascaris
roundworm in feces can be from fert crops w human waste
97
What cells respond to HELMINTHS vs PROTOZOANS
helminths are Th2 and cause eosinophilia
| protists are th1
