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Microbiology Virology - First Aid Flashcards

1
Q

Recombination

A

exchange of genes between 2 chromosomes by crossing over within regions of significant base sequence homology

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2
Q

Reassortment

A

when viruses with segmented genomes (influenza) exchange segments

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3
Q

Compementation

A

when 1 of 2 viruses that infect the cell has a mutation that results in a nonfunctional protein, the nonmutated virus “complements” the mutated one by making a functional protein that serves both viruses

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4
Q

Phenotypic mixing

A

simultaneous infection of a cell with 2 viruses; genome of virus A can be partially or completely coated with the surface proteins of virus B. Type B protein coat determines the tropism of the hybrid virus but the progeny have a type A coat encoded by the type A genetic material

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5
Q

Live attenuated viruses induce…

A

humoral and cell-mediated immunity but have reverted to virulence on occasion. No booster needed.

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6
Q

Killed/inactivated viruses induce….

A

only humoral immunity but are stable.

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7
Q

Live attenuated vaccines (6)

A
  1. smallpox
  2. yellow fever
  3. chickenpox
  4. Sabin polio virus
  5. MMR
  6. influenza (intranasal)
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8
Q

Killed vaccines (4)

A
  1. Rabies
  2. Influenza (injected)
  3. Salk Polio
  4. HAV
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9
Q

Recombinant vaccines (2)

A
  1. HBV

2. HPV

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10
Q

All DNA viruses are dsDNA except…

A

parvoviridae.

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11
Q

All DNA viruses are linear except…

A

papilloma, polyoma and hepadna (which are circular).

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12
Q

All RNA viruses are ssRNA excpet…

A

Reoviridae.

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13
Q

Positive stranded RNA viruses (7)

A 
Retrovirus
Togavirus 
Flavivirus
Coronavirus
Hepevirus
Calicivirus
Picornavirus
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14
Q

Purified nucleic acids of most dsDNA and + strand ssRNA viruses are…

A

infectious.

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15
Q

Naked nucleic acids of - strand ssRNA and dsRNA viruses are…

A

not infectious. They require polymerases conatined in the complete virion.

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16
Q

DNA viruses replicate in…

A

the nucleus, except poxvirus.

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17
Q

RNA viruses replicate in…

A

the cytoplasm, except influenza and retroviruses).

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18
Q

Nake viruses include:

A 
papillomavirus
adenovirus
parvovirus
polyomavirus
calicivirus
picornavirus
reovirus
hepevirus
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19
Q

Generally, viruses acqurie an envelope from…

A

plasma membrane when they exit a cell.

exception: herpesvirus acquires its envelope from the nuclear membrane

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20
Q

DNA viruses (7)

A

HHAPPPP(y)

  1. Hepadna
  2. Herpes
  3. Adeno
  4. Pox
  5. Parvo
  6. Papilloma
  7. Polyoma
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21
Q

DNA viruses general rules (4):

A
  1. are double stranded
  2. are linear
  3. are icosahedral
  4. replicate in the nuclus
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22
Q

The DNA virus that is not double stranded is…

A

parvovirus.

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23
Q

The DNA viruses that are not linear are…

A

papillomavirus/polyomavirus (circular, supercoiled) and hepadnavirus (circular, incomplete).

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24
Q

The DNA virus that is not icosahedral is…

A

poxvirus.

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25
The DNA virus that does not replicate in the nucleus is...
poxvirus (it carries its own DNA-dependent RNA polymerase).
26
DNA viruses w/ an envelope
1. herpesvirus 2. hepadnavirus 3. poxvirus
27
HBV features
- hepadnavirus - hepatitis (acute or chronic) - vaccine (contains surface Ag) - not a retrovirus but has reverse transcriptase
28
Adenovirus medical importance
- febrile pharyngitis (sore throat) - acute hemorrhagic cystitis - pneumonia - conjunctivitis ("pink eye")
29
Parvovirus features (4)
- B19 virus: aplastic crises in sickle cell - "slapped cheeks" rash in children: eythema infectiosum (fifth disease) - RBC destructino in fetus leads to hydrops fetalis and death - pure RBC aplasia/RA-like symptoms in adults
30
Papillomavirus features
HPV: warts (1,2,6,11) CIN Cervical cancer (16, 18)
31
Polyomavirus features
JC virus: PML in HIV | BK virus: transplant pts, commonly targets the kidney
32
Poxvirus features
- smallpox (potential warfare) - cowpox (milkmaid blisters) - molluscum contagiosum (flesh-colored dome lesions with central umbilicated dimple)
33
HSV-1 diseases (4)
- gingivostomatitis - keratoconjunctivitis - temporal lobe encephalitis - herpes labialsi
34
HSV-1 is latent in the...
trigeminal ganglia.
35
HSV-1 is transmitted via....
respiratory secretions and saliva.
36
HSV-2 diseaes
- herpes genitalis | - neonatal herpes
37
HSV-2 is latent in the...
sacral ganglia.
38
HSV-2 is transmitted by...
respiratory secretions.
39
VZV diseases
- chicken pox - shingles - encephalitis - pneumonia
40
VZV is latent in the...
dorsal root or trigeminal ganglia.
41
Most common complication of shingles is...
post-herpetic neuralgia.
42
VZV is transmitted by...
respiratory secretions.
43
EBV causes...
mononucleosis which is characterized by fever, hepatosplenomegaly, pharyngitis and lymphadenopathy (esp. posterior cervical nodes). Transmitted by respiratory secretions/saliva. Commonly seen in teens/YAs.
44
EBV infects...
B cells. But the atypical lymphocytes seen on peripheral blood smear are not infected B cells but rather reactive cytotoxic T cells.
45
EBV is detected by...
positive monospot test - heterophile antibodies detected by agglutination of sheep/horse RBCs.
46
EBV is associated with...
Hodgkin lymphoma, endemic Burkitt lymphoma and nasopharyngeal carcinoma.
47
CMV causes...
- congenital infection - mononucleosis (negative monospot) - pneumonia - retinitis
48
CMV infected cells have...
characteristic "owl eye" inclusions.
49
CMV is latent in...
mononuclear cells.
50
CMV is transmitted...
congenitally and by transfusion, sexual contact, saliva, urine and transplant.
51
HHV-6 causes....
Roseola: high fevers for several days that can cause seizures, followed by a diffuse macular rash. (transmitted by saliva)
52
HHV-8 causes...
Kaposi sarcoma, a neoplasm of endothelial cells. | transmitted by sexual contact
53
Kaposi sarcoma is seen in...
HIV/AIDS and transplant pts.
54
Kaposi sarcoma presents with...
dark/violaceous flat and nodular skin lesions representing endothelial growths. It can also effect GI tract and lungs.
55
HSV Identification
1. viral culture for skin/genitalia 2. CSF PCR for herpes encephalitis 3. Tzanck test
56
The Tzanck smear is a...
smear of opened skin vesicles (from genital herpes) to detect multinucleated giant cells.
57
HSV infected cells also have...
intranuclear Cowdry A inclusions.
58
Reovirus features
Envelope: No RNA structure: DS linear, 10-12 segments Capsid: icosahedral (double)
59
Reovirus disease
1. coltivirus = colorado tick fever | 2. rotavirus = #1 cause of fatal diarrhea in children
60
Picornavirus features
Envelope: No RNA structure: SS + linear Capsid: icosahedral
61
Picornavirus disease
1. Poliovirus - Salk/Sabin vaccines 2. Echovirus = aseptic meningitis 3. Rhinovirus = common cold 4. Coxsackievirus = aseptic meningitis; herpangina; hand, foot and mouth disease; myocarditis, pericarditis 5. HAV = acute viral hepatitis
62
Hepevirus features
Envelope: No RNA structure: SS+, linear Capsid: Icosahedral
63
Hepevirus disease
HEV
64
Calicivirus features
Envelope: No RNA structure: SS + linear Capsid: Icosahedral
65
Calicivirus disease
Norovirus = viral gastroenteritis
66
Flaviviruses features
Envelope: Yes RNA structure: SS + linear Capsid: icosahedral
67
Flaviviruses diseases
1. HCV 2. Yellow fever 3. Dengue 4. St. Louis encephalitis 5. West Nile virus
68
Togavirus features
Envelope: Yes RNA structure: SS+, linear Capsid: Icosahedral
69
Togavirus diseases
1. Rubella 2. Eastern equine encephalitis 3. Western equine encephalitis
70
Retroviruses features
Envelope: Yes RNA structure: SS+, linear Capsid: Icosahedral (HTLV), complex and conical (HIV) (have reverse transcriptase)
71
Retrovirus diseaes
1. HTLV = T-cell leukemia | 2. HIV = AIDS
72
Coronaviruses features
Envelope: Yes RNA structure: SS+, linear Capsid: helical
73
Coronavirus disease
Coronavirus = "common cold" and SARS
74
Orthomyxoviruses features
Envelope: Yes RNA structure: SS+, linear Capsid: helical
75
Orthomyxovirus disease
influenza virus
76
Paramyxovirus features
Envelope: Yes RNA structure: SS-, linear, nonsegmented Capsid: helical
77
Paramyxovirus disease
1. Paramyxovirus = croup 2. RSV = broncholitis in babies 3. Measles/Mumps
78
Rhabdoviruses features
Envelope: Yes RNA structure: SS-, linear Capsid: Helical
79
Rhabdovirus disease
Rabies
80
Filovirus features
Envelope: Yes RNA structure: SS-, linear Capsid: helical
81
Filoviruses Diseases
Ebola/Marburg hemorrhagic fever
82
Arenaviruses features
Envelope: Yes RNA structure: SS-, circular, 2 segments Capsid: Helical
83
Arenaviruses diseases
1. LCMV = lymphocytic choriomeningitis virus | 2. Lassa fever encephalitis = spreads by mice
84
Bunyaviruses features
Envelope: Yes RNA structure: SS-, circular, 3 segments Capsid: helical
85
Bunyaviruses diseases
1. California encephalitis 2. Sandfly/Rift Valley fevers 3. Crimean-Congo hemorrhagic fever 4. Hantavirus = hemorrhagic fever, pneumonia
86
Delta virus features
Envelope: Yes RNA structure: SS-, circular Capsid: uncertain
87
Delta virus disease
HDV is a "defective" virus that requires HBV co-infection.
88
Negative stranded viruses must...
transcribe negative strand to positive. The virion brings its own RNA-dependent RNA polymerase.
89
Negative stranded viruses include (6):
1. Arenaviruses 2. Bunyaviruses 3. Paramyxoviruses 4. Orthomyxoviurses 5. Filoviruses 6. Rhabdoviruses (Always Bring Polymerase Or Fail Replication)
90
Segmented viruses are all...
RNA viruses: 1. Bunyaviruses 2. Orthomyxoviruses 3. Arenaviruses 4. Reoviruses (BOAR)
91
Picornaviruses have RNA that is translated into...
1 large polypeptide that is cleaved by proteases into functional viral proteins.
92
All picornoviruses can casuse aseptic meningitis except...
rhinovirus and HAV.
93
All picornaviruses are enteroviruses which means...
fecal-oral spread. Except for rhinovirus.
94
Features of rhinovirus
-acid labile (destroyed by the stomach acid) and therefore does not infect GI like other picornaviruses
95
Yellow fever virus is a flavivirus (also an arbovirus) transmitted by...
the Aedes mosquitoes. The virus has a monkey or human reservoir.
96
Yellow fever virus symptoms include...
high fever, black vomitus and jaundice.
97
Rotavirus is the major cause of...
acute diarrhea in the US during winter, esp. in day-cars, kindergartens. It causes villous destruction witha trophy leading to decreased absorption of Na+ and loss of K+.
98
Influenza virus contains...
hemagglutinin (promotes viral entry) and neuraminidase (promotes progeny virion release) antigens. Has rapid genetic changes.
99
Influenza virus puts pts at risk for...
fatal bacterial superinfection.
100
Genetic shift/antigenic shifts casues...
pandemics. It is reassortment of the viral genome.
101
During genetic shift, segmetns undergo...
high-frequency recombination, such as when human flu A virus recombines with swine flu A virus.
102
Genetic drift causes...
epidemics. Minor changes are based on random mutation.
103
Rubella causes...
fever, postauricular and other lymphadenopathy, arthralgias and fine rash. It is mild in children but serious congenitally.
104
Congenital rubella findings include...
"blueberry muffin" appearance, indicative of extramedullary hematopoiesis.
105
All paramyxoviruses contain...
F (fusion) protein, which causes respiratory epithelial cells to fuse and form multinucleated cells.
106
Palivizumab is a...
monoclonal antibody against F protein that prevents pneumonia caused by RSV infection in premature infants.
107
Measles characteristic signs are...
Koplik spots and descending maculopapular rash.
108
Koplik spots are...
bright red spots with blue-white center on buccal mucosa that precede the measles rash by 1-2 days.
109
Possible sequelae of Measles are...
1. Subacute sclerosing panencephalitis (SSPE) 2. Encephalitis 3. Giant cell pneumonia
110
SSPE symptoms
behavior changes, myoclonus, ataxia, ocular abnormalities, coma, increased Igs in CSF
111
3 C's of Measles
Cough Coryza Conjunctivitis
112
When infected with the mesles virus, Vitamin A is used to...
prevent severe exfoliative dermatitis in malnourished children.
113
Symptoms of Mumps
1. Parotitis 2. Orchitis 3. aseptic Meningitis -can cause sterility
114
Rabies virus features
- bullet-shaped | - Negri bodies (in purkinje cells and hippocampus)
115
Postexposure treatment for rabies is...
wound cleansing and vaccination +/- rabies immune globulin.
116
Rabies virus travels to...
the CNS by migrating in a retrograde fashion up nerve axons.
117
Progression of rabies disease:
fever/malaise -> agitation/photophobia/hydrophobia -> paralysis/coma -> death
118
Rabies virus in the US is most commonly from...
bat, raccoon and skunk bites.
119
HAV features
1. RNA picornavirus 2. fecal-oral transmission 3. no carrier 4. short incubation (wks) 5. no HCC risk
120
HBV features
1. DNA hepadnavirus 2. parenteral, sexual, maternal-fetal transmission 3. yes carrier 4. long incubation 5. HCC risk bc it integrates into host genome and acts as an oncogene 6. HBV can cause carcinoma w/o cirrhosis!
121
HCV features
1. RNA flavivirus 2. blood transmission (IVDU, transfusion) 3. yes carrier 4. long incubation 5. HCC risk because of chronic inflammation
122
HDV feature
1. RNA delta virus 2. parenteral, sexual, maternal-fetal transmission 3. yes carrier 4. superinfection (HDV after HBV) short incubation 5. coinfection (HDV with HBV) long incubation 6. HCC risk
123
HEV features
1. RNA hepevirus 2. fecal-oral transmission 3. no carrier 4. short incubation 5. no HCC risk 6. high mortality in pregnant mothers
124
In HBV, the DNA polymerase has both....
DNA and RNA dependent activities. UPon entry into the nucleus, the polymerase functions to complete the partial dsDNA. The host RNA polymerase transcribes mRNA from viral DNA to make viral proteins. The DNA polymerase then reverse transcribes viral RNA to DNA to make new viral particles.
125
Anti-HAV (IgM)
IgM antibody to HAV; best test to detect active hep A
126
Anti-HAV (IgG)
IgG antibody indicates prior HAV infection and/or prior vaccination; protects against reinfection
127
HBsAg
Ag found on surface of HBV; indicates Hep B infection
128
HBcAg
antigen associated with core of HBV (indicates actual infection rather than immunization)
129
Anti-HBc
antibody to HBcAg; IgM = acute/recent infxn; IgG = prior exposure or chornic infection; positive during window period
130
HBeAg
a second, different antigenic determinant in the HBV core. HBeAg indicates active viral replication and therefore high transmissibility.
131
Anti-HBe
antibody to HBeAg; indicates low transmissibility
132
ALT > AST indicates...
viral hepatitis.
133
AST > ALT indicates...
alcoholic hepatitis.
134
The 3 structural genes of HIV are...
1. env (gp120 and gp41) 2. gag (p24) - capsid protein 3. pol (reverse transcriptase, aspartate protease, and integrase
135
Env is formed from...
cleavage of gp160 to form envelope glycoproteins.
136
gp120 is for...
attachement of HIV to host CD4+ T cell.
137
gp41 is for...
fusion and entry.
138
HIV dsDNa is able to...
integrate into host genome.
139
The HIV virus binds...
CCR5 or CXCR4 co-receptor and CD4 on T cells. It binds CCR5 and CD4 on macrophages.
140
Homozygous CCR5 mutation gives...
immunity to HIV. Heterozygous mutation causes a slower course.
141
A presumptive diagnosis of HIV is made with...
ELISA (sensitive, high false-positive rate and low threshold).
142
+ ELISA for HIV is then confirmed with...
Western blot assay (specific, high false-negative rate and high threshold).
143
AIDS diagnosis is...
less than 200 CD4+ cells.
144
ELISA/Western blot tests look for...
antibodies to viral proteins; these are often falsely negative in the first 1-2 months of HIV infection and falsely positive in babies born to infected mothers because anti-gp120 crosses the placenta.
145
During the latent phase of HIV, the virus...
replicates in LNs.
146
Prion diseases are caused by...
the conversion of a normal (predominantly alpha-helical) prion protein (PrPc) to a beta-pleated sheet form (PrPsc) which is transmissible.
147
PrPsc resists...
protease degradation and facilitates the conversion of still more PrPc to PrPsc.
148
Accumulation of PrPsc results in...
spongiform encephalopathy and dementia, ataxia and death.
149
Types of Prion Disease
1. Creutzfeldt-Jacob disease (sporadic, rapidly progressive dementia) 2. Gerstmann (inherited) 3. Kuru (acquired)

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