Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Microbiology > Viruses > Flashcards

Viruses Flashcards

(95 cards)

Start Studying
1
Q

Recombination

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Reassortment

A

When viruses with segmented genomes (flu) exchange segments. High frequency recombination. Cause of worldwide influenze pandemics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Complementation

A

When 1 or 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.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Phenotypic mixing

A

Occurs with simultaneous infection of a cell with 2 viruses. Genome of virus A can be partially or completely coated (forming pseudovirion) with the surface protiens of virus B. Type B protein coat determines the tropism (infectivity) of the hybrid virus. However, the progeny from this infection have a type A coat that is encoded by its type A genetic material.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Live attenuated vaccine - what response?

Types?

A

Induce hemoral and cell-mediated immunity but have reverted to virulence on rare occasions.
Smallpox, yellow fever, chickenpox, Sabin’s polio virus, MMR, influenza (intranasal)
Dangerous to give to IC and no booster needed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Killed vaccine

A

Rabies, influenza (IV), Salk Polio, HAV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Recombinant vaccine

A

HBV, HPV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Only ssDNA virus

A

Parvoviridae

All others are dsDNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Circular DNA virus

A

Papilloma
Polyoma
Hepadnaviruses
All others are linear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Only dsRNA virus

A

Reoviridae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Positive stranded RNA viruses

A

retrovirus, togavirus, flavivirus, coronavirus, hepevirus, calicivirus, picornavirus (I went to a retro toga party, where I drank flavored Corona and ate hippy California pickles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Ploidy of viruses

A

all viruses are haploid (1 copy of DNA or RNA) except retroviruses which have 2 identical ssRNA molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where does DNA viruses replicate? RNA?

A

nucleus (except poxvirus)

cytoplasm (except influenza, retroviruses)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Non-enveloped viruses (Naked)

A

Papillomavirus, Adenovirus, Picornavirus, Polyomavirus, Calcivirus, Parvovirus, Reovirus, Hepevirus (Give PAPP (DNA) smears and CPR (RNA) to a naked Heppy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Herpesviruses
Envelope:
Structure:
Dz: 8

A 
Herpesviruses
Envelope: yes
Structure: dsDNA and linear
Dz: 
(1) HSV1 - oral/genital lesions, temporal lobe encephalitis, keratoconjunctivitis
(2) HSV2 - genital lesions
(3) VSV - chickenpox, zoster (shingles)
(4) EBV - mono, Burkitt's lymphoma, Hodgkin's lymphoma
(5) CMV - infxn in IC patients esp transplant recipients; congenital defects 
(6) HHV6 - roseola (exanthem subitum)
(7) HHV7 - less common cause of roseola
(8) HHV8 - Kaposi's sarcoma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Hepadnavirus
Envelope:
Structure:
Dz:

A

Hepadnavirus
Envelope: Yes
Structure: dsDNA and partial circular
Dz: (1) HBV - acute/chronic hepatitis, vaccine available (HBV surface Ag), reverse transcriptase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Adenovirus
Envelope:
Structure:
Dz:

A

Adenovirus
Envelope: No
Structure: dsDNA and linear
Dz: Febrile pharyngitis (sore throat, acute hemorrhagic cystitis), pneumonia, conjunctivitis (pink eye)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Parvovirus
Envelope:
Structure:
Dz:

A

Parvovirus
Envelope: No
Structure: ssDNA and linear
Dz: B19 virus - aplastic crises in sickle cell disease with slapped cheeks rash in children, erythema infectiosum (fifth disease), RBC destruction in fetus leads to hydrops fetalis and death, pure RBC aplasia and rheumatoid arthritis like symptoms in adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Papillomavirus
Envelope:
Structure:
Dz:

A

Papillomavirus
Envelope: No
Structure: dsDNA and circular
Dz: HPV - warts (1, 2, 6, 11), CIN/cervical cancer (16, 18); vaccine available

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Polyomavirus
Envelope:
Structure:
Dz: 2

A

Polyomavirus
Envelope: No
Structure: dsDNA and circular
Dz: JC virus - progressive multifocal leukoencephalopathy in HIV
BK virus - transplant patients (targets kidney)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Poxvirus
Envelope:
Structure:
Dz:

A

Poxvirus
Envelope: Yes
Structure: dsDNA and linear (largest DNA virus)
Dz: Smallpox
Vaccinia - cowpox
Molluscum contagiosum - flesh colored dome lesions with central dimple

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

HSV-1
Transmission:
Dz:

A

HSV-1
Transmission: respiratory secretions, saliva
Dz: gingivostomatitis, keratoconjunctivitis, temporal love encephalitis (MCC sporadic encephalitis in US), herpes labialis, latent in trigeminal ganglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

HSV-2
Transmission:
Dz:

A

HSV-2
Transmission: Sexual contact, perinatal
Dz: Herpes genitalis, neonatal herpes, latent in sacral ganglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

VZV
Transmission:
Dz:

A

VZV
Transmission: respiratory secretions
Dz: varicella-zoster (chickenpox, shingles), encephalitis, pneumonia, latent in dorsal root or trigeminal ganglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
EBV Transmission: Dz: Clinical:
EBV Transmission: respiratory secretions, saliva Dz: Infectious mono, Burkitt's/Hodgkin's lymphoma, nasopharyngeal carcinoma, latent in B cells Clinical: fever, hepatosplenomegaly, pharyngitis, lymphadenopathy (posterior cervical nodes), 15-20 yoa, atypical lymphocytes on peripheral - reactive cytotoxic T cells; positive Monospot
26
CMV Transmission: Dz:
CMV Transmission: congenital, transfusion, sexual contact, saliva, urine, transplant Dz: congenital infxn, mono (negative monospot), pneumonia, retinitis; owl's eye inclusions; latent in mononuclear cells
27
HHV-6 | Dz:
HHV-6 | Dz: roseola - high fevers for several days that can cause seizures, followed by a diffuse macular rash
28
HHV-8 Transmission: Dz:
HHV-8 Transmission: sexual contact Dz: Kaposi's sarcoma (HIV patietns)
29
HSV diagnosis
PCR is test of choice Tzanck test - smear of opened skin vesicle to detect multinucleared giant cell Intranuclear Cowdry A inclusions
30
``` Reovirus Envelope: Structure: Capsid: Dz: 2 ```
``` Reovirus Envelope: no Structure: dsRNA linear Capsid: icosahedral Dz: (1) coltivirus - Colorado tick fever (2) rotavirus - fatal diarrhea in children ```
31
``` Picornaviruses Envelope: Structure: Capsid: Dz: 5 ```
``` Picornaviruses Envelope: no Structure: ssRNA linear Capsid: icosahedral Dz: (1) poliovirus - Salk/Sabin vaccine (2) echovirus - aseptic meningitis (3) Rhinovirus - common cold, acid labile so destroyed in stomach (4) Coxsackievirus - aseptic meningitis; herpangina (mouth blisters, fever); hand, food, and mouth disease, myocarditis (5) HAV - acute viral hepatitis ``` PERCH
32
``` Hepevirus Envelope: Structure: Capsid: Dz: ```
``` Hepevirus Envelope: No Structure: ssRNA linear Capsid: Icosahedral Dz: HEV ```
33
``` Caliciviruses Envelope: Structure: Capsid: Dz: ```
``` Caliciviruses Envelope: no Structure: ssRNA linear Capsid: icosahedral Dz: Norovirus - viral gastroenteritis ```
34
``` Flaviviruses Envelope: Structure: Capsid: Dz: 5 ```
``` Flaviviruses Envelope: Yes Structure: ssRNA linear Capsid: icosahedral Dz: HCV Yellow fever Dengue St. Louis encephalitis West Nile virus ```
35
``` Togaviruses Envelope: Structure: Capsid: Dz: 3 ```
``` Togaviruses Envelope: yes Structure: ssRNA linear Capsid: icosahedral Dz: Rubella Eastern equine encephalitis Western equine encephalitis ```
36
``` Retroviruses Envelope: Structure: Capsid: Dz: 2 ```
``` Retroviruses Envelope: yes Structure: ssRNA linear Capsid: icosahedral (HTLV), complex&conical (HIV) Dz: HTLV - t cell leukemia HIV - AIDS ```
37
``` Coronaviruses Envelope: Structure: Capsid: Dz: 2 ```
``` Coronaviruses Envelope: yes Structure: ssRNA linear Capsid: helical Dz: coronavirus - common cold SARS ```
38
``` Orthomyxoviruses Envelope: Structure: Capsid: Dz: ```
``` Orthomyxoviruses Envelope: yes Structure: ssRNA (-) linear, 8 segments Capsid: helical Dz: Influenza virus ```
39
``` Paramyxoviruses Envelope: Structure: Capsid: Dz: 4 ```
``` Paramyxoviruses Envelope: yes Structure: ssRNA (-) linear, nonsegmented Capsid: helical Dz: Parainfluenza - croup RSV - bronchiolitis in babies give ribavirin for tx Measels Mumps ```
40
``` Rhabdoviruses Envelope: Structure: Capsid: Dz: ```
``` Rhabdoviruses Envelope: yes Structure: ssRNA (-) linear Capsid: helical Dz: rabies ```
41
``` Filoviruses Envelope: Structure: Capsid: Dz: ```
``` Filoviruses Envelope: yes Structure: ssRNA (-) linear Capsid: helical Dz: Ebola/Marburg hemorrhagic fever often fatal ```
42
``` Arenaviruses Envelope: Structure: Capsid: Dz: 2 ```
Arenaviruses Envelope: yes Structure: ssRNA (-) circular, 2 segments Capsid: helical Dz: LCMV - lymphocytic choriomeningitis virus Lassa fever encephalitis - spread by mice
43
``` Bunyaviruses Envelope: Structure: Capsid: Dz: 4 ```
``` Bunyaviruses Envelope: yes Structure: ssRNA (-) circular, 3 segments Capsid: helical Dz: California encephalitis Sandfly/Rift Valley fever Crimean-Congo hemorrhagic fever Hantavirus - hemorrhagic fever, pneumonia ```
44
``` Delta virus Envelope: Structure: Capsid: Dz: ```
``` Delta virus Envelope: yes Structure: ssRNA (-) circular Capsid: not sure Dz: HDV - "defective" virus that requires HBV co-infection ```
45
Importance of (-) stranded viruses
``` must transcribe (-) to (+) - virion brings its own RNA-dependent RNA polymerase Arenaviruses Bunyaviruses Paramyxoviruses Orthomyxoviruses Filoviruses Rhabdoviruses (Always Bring Polymerase Or Fail Replication) ```
46
Segmented viruses
``` All are RNA Bunyaviruses Orthomyxoviruses Arenaviruses Reovirus (BOAR) ```
47
Yellow fever
flaviviruse Aedes mosquitos (monkey or human reservoir) high fever, black vomitus, jaundice
48
most important global cause of infantile gastroenteritis?
segmetned dsRNA virus - Rotavirus acute diarrhea in US during winter esp in day-care, kindergartens villous destruction with atrophy leads to decreased absorption of Na and loss of K
49
influenza
orthomyxoviruses - enveloped, (-) ssRNA with 8 segments contain hemagglutinin (viral entry) and neuraminidase (progeny virion release) antigens rapid genetic changes killed viral vaccine is major mode of protection, reformulated vaccine offered each fall
50
genetic shift
cuases pandemics reassortment of viral genome segments undergo high frequency recombination, such as when human flu A virus recombines with swine flu A virus
51
genetic drift
causes epidemics, minor changes based on random mutation
52
rubella virus
togavirus German measles - fever, postauricular adenopathy, lymphadenopathy, arthralgias, fine truncal rash that starts at head and moves down. Mild disease in children but serious congenital disease (TORCH)
53
paramyxoviruses
disease in children croup, mumps, measles, RSV (respiratory tract infection in infants) contain surface F (fusion) protein causes respiratory epi cells to fuse and form multinucleated cells Palivizumab (monoclonal Ab against F protein) prevents pneumonia caused by RSV infection in premature infants
54
measles virus
paramyxoviruse Kopli spots (red spots with blue-white center on buccal mucosa) and descending maculopapular rash SSPE (subacute sclerosing panencephalitis), encephalitis, giant cell pneumonia Rash from head to toe - hands/feet
55
mumps viruse
paramyxovirus Parotitis, orchitis, aseptic meningitis can cause sterility
56
rabies virus
Bullet shaped virus Negri bodies characteristic cytoplasmic inclusions in neurons infected by rabies (Purkinje cells of cerebellum - travels retrograde up nerve axons) Weeks to months incubation Fever, malaise --> agitation, photophobia, hydrophobia --> paralysis, coma --> death Bat, raccoon, skunk bites
57
``` HAV Type: Transmission: Incubation: Cancer risk: Clinical: ```
``` HAV Type: RNA picornavirus Transmission: fecal-oral Incubation: short Cancer risk: No Clinical: asymptomatic, acute, no carrier ```
58
``` HBV Type: Transmission: Incubation: Cancer risk: Clinical: ```
HBV Type: DNA hepadnavirus Transmission: parenteral, sexual, materal-fetal Incubation: long Cancer risk: yes bc integrates into host genome Clinical: carrier
59
``` HCV Type: Transmission: Incubation: Cancer risk: Clinical: ```
HCV Type: RNA flavivirus Transmission: blood, IVDU, post-transfusion Incubation: long Cancer risk: yes from chronic inflamm Clinical: chronic, cirrhosis, carcinoma, carrier
60
``` HDV Type: Transmission: Incubation: Cancer risk: Clinical: ```
HDV Type: RNA delta virus Transmission: parenteral, sexual, maternal-fetal Incubation: superinfection is short; co-infection is long Cancer risk: yes Clinical: defective virus that is dependent on HBV superinfection - decrease prognosis
61
``` HEV Type: Transmission: Incubation: Cancer risk: Clinical: ```
HEV Type: RNA hepevirus Transmission: fecal-oral (waterborne epidemics) Incubation: short Cancer risk: none Clinical: high mortality in pregnant, enteric, expctant mothers, epidemic
62
Anti-HAV - IgM
IgM antibody to HAV | best test to detect active hepatitis A
63
Anti-HAV - IgG
IgG antibody indicates prior HAV infection and/or prior vaccination; protects against reinfection
64
HBsAg
Antigen found on surface of HBV; indicates hepatitis B infection
65
Anti-HBs
Antibody to HBsAg | Indicates immunity to hepatitis B
66
HBcAg
Antigen associated with core of HBV
67
Anti-HBc
Antibody to HBcAg IgM - acute/recent infection IgG - prior exposure or chronic infection Positive during window period
68
HBeAg
A second, different antigenic determinant in the HBV core, HBeAg indicates active viral replication and therefore high transmissibility
69
Anti-HBe
Antibody to e antigen; indicates low transmissibility
70
viral hepatitis ALT vs AST
ALT > AST
71
alcoholic hepatitis ALT vs AST
AST > ALT
72
Acute HBV serologic markers
HBsAg, HBeAg, IgM Anti-HBc
73
Window period of HBV serologic markers
Anti-HBe and IgM Anti-HBc
74
Chronic HBV with high infectivity serologic markers
HBsAg, HBeAg, IgG Anti-HBc
75
Chronic HBV with low infectivity serologic markers
HBsAg, Anti-HBe, IgG Anti-HBc
76
Recovery from HBV serologic markers
Anti-HBs, Anti-HBe, IgG Anti-HBc
77
Immunized to HBV serologic markers
Anti-HBs
78
``` HIV Structure: Virulence: Immunity: Slower Course: ```
HIV Structure: diploid genome (2 molecules of RNA); 3 genes (1) env from gp120 attachment to host CD5+ T cell and gp41 fusion and entry (2) gag - capsid protein (3) pol - reverse transcriptase, aspartate protease, integrase Virulence: reverse transcriptase synthesizes dsDNA from RNA --> dsDNA integrates into host genome Immunity: homozygous CCR5 mutation (virus binds this late) co-receptor Slower Course: heterozygous CCR5 mutation (virus binds this early)
79
HIV diagnosis
Presumptive dx: ELISA (sensitive, high false positive rate and low threshold rule out test) Western blot assay (specific, high false negative rate and high threshold, rule in test) Both look for antibodies to viral proteins - falsely neg in first 1-2 months of HIV infection and falsely positive initially in babies born to infected mothers
80
HIV prognostic test
PCR/viral load test - amount of viral RNA in the plasma High viral load associated with poor prognosis Also used to monitor effect of drug therapy
81
AIDS Dx
diagnosis <1.5 1. flu-like (acute) 2. feeling fine (latent) 3. falling count 4. final crisis
82
Immunocompromised CD4
<400 CD4+ cell/mm3
83
AIDS-defining illnesses emerge
<200 CD4+ cells/mm3
84
Systemic disease of HIV +
Low grade fevers, cough, hepatosplenomegaly, tongue ulcer Oval yeast cells w/i macrophages CD4 < 100 Histoplasma capsulatum (usually just pulmonary sx in healthy)
85
Dermatologic disease of HIV +
Fluffy white cottage-cheese lesions: pseudohyphae, commonly oral if CD4 C. albicans Superficial vascular proliferation: PMN inflammation --> Bartonella henselae (bacillary angiomatosis)
86
Gastrointestinal disease of HIV +
Chronic, watery diarrhea: acid fast cysts seen in stool when CD4 < 200 --> Cryptosporidum
87
Encephalopathy of HIV +
reactivation of latent virus --> demyelination (CD4 < 200) --> JC virus reactivation (PML)
88
Abscesses of HIV +
Many ring enhancing lesions on imaging, CD4 Toxoplasma gondii
89
Meningitis of HIV +
India ink stain reveals yeast with narrow based budding and large capsule, CD4 < 50 --> cryptococcus neoformans
90
Retinitis of HIV +
Cotton wool spots on funduscopic exam and may also occur with esophagitis, CD4 < 40 --> CMV
91
Dementia of HIV +
Directly associated with HIV
92
Oncologic disease of HIV +
HHV-8 (Kaposi's sarcoma): biopsy reveals lymphocytic inflamm --> superficial neoplastic proliferation of vasculature EBV: lateral tongue --> hairy leukoplakia EBV: oropharynx (Waldeyer's ring) --> Non-Hodgkin's lymphoma (large cell type) HPV: often in anus or cervix --> SCC EBV: focal or multiple --> primary CNS lymphoma
93
Respiratory diseases of HIV +
CMV --> biopsy reveals cells with intranuclear (owl's eye) inclusion bodies --> interstitial pneumonia Aspergillus fumigatus --> pleuritic pain, hemoptysis, infiltrates on imaging --> invasive aspergillosis Pneumocystis jirovecii --> CD4 Pneumonia Mycobacterium avium-intracellulare --> CD4 tuberculosis like disease
94
Prions Mutation? Presentation? Types?
Caused by conversion of a normal cellular protein termed prion protein (PrPc) to a beta-pleated form (PrPsc) which is transmissible. PrPsc resists degradation and facilitates the conversion of still more PrPc to PrPsc. Spongiform encephalopathy and dementia, ataxia, and death. Creutzfeldt-Jakob diseae = sporadic with rapidly progressive dementia Gerstmann-Straussler-Scheinker syndrome = inherited Kuru = acquired
95
Prions Mutation? Presentation? Types?
Caused by conversion of a normal cellular protein termed prion protein (PrPc) to a beta-pleated form (PrPsc) which is transmissible. PrPsc resists degradation and facilitates the conversion of still more PrPc to PrPsc. Spongiform encephalopathy and dementia, ataxia, and death. Creutzfeldt-Jakob diseae = sporadic with rapidly progressive dementia Gerstmann-Straussler-Scheinker syndrome = inherited Kuru = acquired

Microbiology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions