Microbiology: Virology Flashcards
1
Q
All viruses have this structure
A
Capsid (protein coat) made up of capsomeres
2
Q
What is a matrix protein or tegument (viral structure)?
A
Interstitial space between nucleocapsid and the envelope
3
Q
Viral lipid membrane derived from the host cell
A
Envelope
4
Q
All viral envelopes are acquired through budding from the plasma membrane except
A
Herpes virus (from nuclear membrane)
5
Q
Enveloped viruses are ___ stable and ___ easily activated
A
less stable, more easily activated
6
Q
Compared to enveloped viruses, naked viruses
A
tend to be more resistant to damage
7
Q
Viral symmetric: spherical (icosahedral) or helical
Which is enveloped?
A
Both may be enveloped, but icosahedral viruses can also be naked
8
Q
What viruses are naked?
A
Naked Viruses: Naked CPR and PAPP smear Calici Picorna Reo Parvo Adeno Papilloma Polyoma
9
Q
All viruses are haploid, T or F?
A
False, Retroviruses are not haploid
10
Q
RNA viruses have a segmented genome which contributes to
A
Genetic diversity
Better for mixing with other viral genomes
11
Q
Segmented Genome Viruses
A
BOAR Bunyaviruses Orthomyxoviruses (influenza) Arenaviruses Reoviruses
12
Q
This type of virus brings its own RNA-dependent RNA polymerase
A
Negative Strand RNA Viruses
13
Q
Negative Strant RNA Viruses
A
Always Bring Polymerase Or Fail Replication Arenaviruses Bunyaviruses Paramyxoviruses Filoviruses Rhabdoviruses
14
Q
Drug class and stage affected in viral life cycle: Enfuvirtide (T-20)
A
Fusion inhibitor
Adsorption/attachment
15
Q
Drug class and stage affected in viral life cycle: Amantadine
A
Penetration and uncoating
For influenza, Type A only
16
Q
Drug class and stage affected in viral life cycle: Acyclovir, Ribavirin
A
Viral DNA/RNA synthesis
17
Q
Drug class and stage affected in viral life cycle:
Lamivudine
Zidovudine
Nevirapine
A
Viral DNA/RNA synthesis
18
Q
Drug class and stage affected in viral life cycle: Interferon
A
Viral protein synthesis
19
Q
Drug class and stage affected in viral life cycle: Protease inhibitors
A
Assembly and re-assembly
20
Q
What property of viruses enables them to cause epidemics?
A
Genomic reassortment
21
Q
One virus produces a protein that can also be used by another virus, give an example
A
Complementation
You can only have HepD if you have HepB
22
Q
Phenotypic mixing
A
Two different viruses infect the same cell, leading to production of new strains
23
Q
Outcomes of viral infection: Cytopathic effect
A
Visual or functional change in infected cells
24
Q
Outcomes of viral infection: Malignant transformation
A
Oncogenic viruses induce transformation and unrestrained growth
25
Outcomes of viral infection: Commensal symbiosis
Infected cells appear normal, but are producing large numbers of progeny viruses
26
3 virulence factors and their description
Antigenic variants of surface proteins - change the "face" of the virus
Cytokine decoys - bind cytokines and block their ability to interact with receptors on their intended targets
Virokines - reduce the expression of antigen presenting cells and inactivate complement
27
States of persistent viral infections: HepB, HepC, HIV
Carrier state
Produce virus for long periods of time, serve as a source of infection
28
States of persistent viral infections: Herpes zoster (VZV)
Latent infections
No active viral reproduction, but can be reactivated at a subsequent time
29
States of persistent viral infections: HIV, Rabies
Slow virus infections
Long incubation period, often measured in years
30
Finding an antibody to a virus in a patient who previously had no antibodies to that specific virus
Seroconversion
31
7 diagnostic techniques for viral infections
```
ELISA
RIA
Hemagglutination inhibition
Complement fixation
Neutralization
FAA
PCR
```
32
Gold standard in viral diagnosis?
Presence of viral DNA or RNA in the sample
33
Which viruses have p24?
HIV, HepB
34
What is the first vaccine produced that prevents human cancer?
HepB (decreased HCC)
35
ssDNA naked virus, icosahedral, linear
Parvovirus B19
The only DNA virus that is not double-stranded
Only has one serotype
36
dsDNA naked virus, icosahedral, linear
Adenovirus
37
dsDNA enveloped virus, icosahedral, circular
Hepadnavirus B (HepB)
38
DNA Viruses
DNA Viruses are HHAPPPPy viruses! (if not one of these, the virus is an RNA virus)
```
Hepadna
Herpes
Adeno
Papilloma
Parvo
Polyoma
Pox
```
39
All DNA viruses have linear DNA except
Hepadna
Papilloma
Polyoma
40
All DNA viruses are icosahedral and replicate in the nucleus except
Poxvirus
41
Where is the inclusion body in DNA viruses?
Nucleus
42
Where is the inclusion body in RNA viruses?
Cytoplasm
43
Naked virus: Parvovirus B19
Mode of transmission
Oncogenic?
Vaccine?
Naked virus: Parvovirus B19
Mode of transmission: respiratory, transplacental
Oncogenic? No
Vaccine? No
44
Naked virus: Adenovirus
Mode of transmission
Oncogenic?
Vaccine?
Naked virus: Adenovirus
Mode of transmission: respiratory, fecal-oral
Oncogenic? No
Vaccine? Yes
45
Naked virus: Human papillomavirus
Mode of transmission
Oncogenic?
Vaccine?
Naked virus: Human papillomavirus
Mode of transmission: sexual, skin contact
Oncogenic? Yes
Vaccine? Yes
46
Slapped cheek and other signs of erythema infectiosum, fifth disease
Parvovirus B19
47
Parvovirus B19 causes what in the second trimester?
Hydrops fetalis
48
Chronic Parvovirus B19 infection in immunodeficient patients
Pancytopenia
49
Has penton fibers and 41 antigenic types
Adenovirus
50
Cowdry Type A intranuclear inclusions
| Cowdry Type B intranuclear inclusions
Type A: herpes simplex, VZV, CMV infections and Yellow fever
| Type B: Adenovirus, Poliovirus
51
Virus that causes hemorrhagic cystitis and conjunctivitis
Adenoviridae
52
Three strains of Papovaviridae
Human papilloma virus
JC polyoma virus
BK polyoma virus
53
BK polyoma virus disease manifestation
Only in immunocompromised
| BK (bone and kidney) transplant patients may develop hemorrhagic cystitis and nephropathy
54
JC polyoma virus disease manifestation
Only in immunocompromised
Progressive multifocal leukoencephalopathy in patients with AIDS
DDx: Multiple sclerosis
55
HPV Vaccines
Bivalent - Cervarix - 16 and 18
| Quadrivalent - Gardasil - 6, 11, 16, 18
56
Koilocytes are a pathological finding in this viral infection
HPV
57
Functions of genes E6 and E7 in HPV pathogenesis
Inactivation of TSG
E6- inhibits p53
E7 - inhibits Rb
58
HPV 1 to 4
Common name
Location
HPV 1 to 4
Common name: verruca vulgaris
Location: skin and plantar area (liquid nitrogen and salicylic acid)
59
HPV 6 and 11
Common name
Location
HPV 6 and 11
Common name: genital warts/ condyloma accuminata
Location: genital area (podophyllin), respiratory tract
Most common viral STD!
60
HPV 16, 18, 31, 33
| Location
16 and 18 are high risk strains
| Carcinomas of: penis, anus, vulva, cervix
61
```
Diseases caused by Herpesviridae:
HHV 6
HHV 8
HSV 1
HSV 2
VZV
EBV
CMV
```
```
Diseases caused by Herpesviridae:
HHV 6: roseola infantum
HHV 8: Kaposi sarcoma
HSV 1: oral herpes (gingivostomatitis, labialis, keratoconjunctivitis, temporal lobe encephalitis, herpetic whitlow - fingers, herpes gladiatorum - trunk)
HSV 2: genital, neonatal, aseptic meningitis
VZV: varicella zoster
EBV: infectious mononucleosis
CMV: congenital mononucleosis
```
62
Site of HSV latency:
HSV 1
HSV 2
Site of HSV latency:
HSV 1: trigeminal ganglia
HSV 2: lumbosacral ganglia
63
DOC for HSV?
Acyclovir
Shortens duration of the lesions
Reduces extent of shedding
No effect on latent state (not actively replicating, no viral kinase produced)
64
DOC for VZV
Moderate to severe is Acyclovir
65
Ramsay Hunt syndrome
VZV: Zoster
Dermatomal, postherpetic neuralgia
Hutchinson sign
Herpes zoster otticus
Herpes zoster ophthalmicus
66
Reye syndrome, vesicular, centrifugal rash, "dewdrop on a rose"
VZV: Varicella
| Hides in dorsal root ganglia until it reactivates as zoster
67
Multinucleated giant cells with intranuclear inclusions
VZV
68
Negative heterophil test, giant cells with owl's eye intranuclear inclusions
CMV
69
DOC for CMV
Ganciclovir
70
Most common cause of congenital abnormalities
CMV
71
Diseases that cause "Blueberry muffin lesions"
Congenital CMV: microcephaly, seizures, deafness, jaundice, purpura, 1st trimester
Congenital rubella
Congenital/disseminated neuroblastoma
72
HHV 4, "kissing disease", rare complication is splenic rupture
EBV
73
Positive heterophil test, affects B lymphocytes (B cell lymphomas)
EBV
74
Oral hairy leukoplakia in immunocompromised patients is seen in those infected with
EBV
75
EBV-infected African boy with facial asymmetry
Burkitt lymphoma
76
Nasopharyngeal carcinoma in Chinese
EBV
77
DDx: Bartonella (cat scratch disease) basillary angiomatosis
Kaposi Sarcoma - malignancy of vascular endothelial cells, an AIDS-defining illness
78
Guarnieri bodies on histopathology, intracytoplasmic eosinophilic inclusions
Smallpox/Variola
79
Largest virus, has been eradicated
Smallpox/Variola
80
DOC if Cifodovir, Henderson-Peterson bodies (intracytoplasmic eosinophilic inclusions) on histopathology, skin lesion with umbilicated center
Molluscum contagiosum virus
81
Enveloped virus with incomplete circular dsDNA
Hepatitis B
82
Hepatitides and their characteristics
```
The VOWELS (A and E) his your BOWELS.
Hep A and E cause enteric infections
```
Hep A = Asymptomatic (Picornaviridae)
Hep B = Blood-borne (Hepadnaviridae)
Hep C = Chronic, cirrhosis, carcinoma, carriers (Flaviviridae)
Hep E = Enteric, expectant mothers, epidemics (Caliciviridae)
83
Virulence factors of HepB
```
Surface antigen (HBsAg)
Core antigen (HBcAg)
e antigen (HBeAg) - seen in blood if virus is actively replicating
```
84
Only DNA virus that produces DNA by reverse transcription, with mRNA as template, targeted by Lamivudine
HepB
85
Interpret HepB profile: IgM anti-HBcAg (+)
New infection
Most specific marker for diagnosis of acute HBV infection because it persists during the window period
Recall: HepB profile interpretation
86
Presence of HBeAg connotes
"e" = "enfectivity"(high activity of DNA replication)
87
This HepB antigen describes whether the patient is diseased or immune
Surface antigen
88
These HepB antigens tell us how long the infection has been present
Core antigens
89
DOC for HepB
Interferon alpha
| Lamivudine
90
Reverse transcriptase functions as
RNA-dependent DNA polymerase
91
Lamivudine is an anti-retroviral drug which inhibits reverse transcriptase. It is useful in the treatment of which 2 viral infections?
HIV
| HepB
92
All RNA viruses have single-stranded DNA except
Reovirus
| Rotavirus
93
All RNA viruses replicate in the cytoplasm except
Influenza
| Retrovirus
94
Picornaviridae viruses
PERCHed on a PIC
```
Poliovirus
Echovirus
Rhinovirus
Coxsackie virus
Hepatitis A virus
Picornaviridae
```
95
Difference between the 2 polio vaccines
Killed - Salk - IPV
| Live attenuated - Sabin - OPV (antigenically superior)
96
This virus replicates in the motor neurons of the anterior horn of the spinal cord causing paralysis
Poliovirus
97
Group A Coxsackie spectrum of disease
Herpangina
Hemorrhagic conjunctivitis
Hand-foot-and-mouth disease
98
Group B Coxsackie spectrum of disease
Pleurodynia
| Myocarditis and pericarditis
99
Group A and B Coxsackie spectrum of disease
Aseptic or viral meningitis (along with Polio and Echo)
100
What does ECHOvirus stand for?
Enteric Cytopathic Human Orphan
101
Only non-enteric virus of Picorna
Rhinovirus
They are acid-labile, killed by gastric acid when swallowed
The real "colds": RHINO has a runny nose.
102
Children are most frequently infected, a.k.a. Enterovirus 72
Hepatitis A
103
Caliciviridae virus that has high mortality in pregnant women
Hepatitis E
104
Most common cause of nonbacterial diarrhea in adults, viral gastroenteritis
Norwalk Virus or Norovirus
| Caliciviridae
105
Most common cause of childhood diarrhea, viral gastroenteritis
Rotavirus (Right Out the Anus)
| Reoviridae
106
Ensures genetic diversity in influenza
Envelope
| Contains the 2 antigens: Hemagglutinin and Neuraminidase
107
Influenza strain exclusive to humans, causes major outbreaks
Influenza B
108
Influenza strain causing worldwide epidemics (pandemics)
Influenza A
109
Antigen in influenza responsible for binding, the target of neutralizing antibody, 16 types
Hemagglutinin
110
Influenza antigen for entry and release, cleaves neuraminic acid (sialic acid) to release progeny virus from the infected cell, 9 types
Neuraminidase
111
Reason that there is a new vaccine yearly for influenza, causes epidemics
Influenza B antigenic drift
Sudden Shift is more deadly than graDual Drifts.
112
Major changes based on the reassortment of segments of the genome RNA, causes pandemics
Antigenic shift
113
DOC for inluenza
Oseltamivir
Zanamivir
Amantadine is for Influenza A only
114
Strain combination in yearly flu vaccine
2 A strains
| 1 B strain
115
Envelope spikes that may be present in Paramyxoviridae
```
Hemagglutinin (only RSV does not have this)
Neuraminidase (Mumps and Parainfluenza only)
Fusion protein (all have this)
```
116
Paramyxoviruses
```
PaRaMyxoviruses
Parainfluenza virus
RSV
Measles
Mumps
```
117
Histopathologic finding of Warthin-Finkeldey bodies (multinucleated giant cells)
Measles Virus
118
Maculopapular rash progression in measles
face - trunk - extremities - palms and soles
119
Complications of measles virus infection
Encephalitis
Pneumonia
Subacute sclerosing panencephalitis (SSPE)
120
Cardinal manifestations of measles
Cough, Coryza, Conjunctivitis, Koplik spots
121
Vitamin A supplementation reduces the severity of this disease
Measles
122
Mumps spectrum of disease
Mumps make your parotids and testes as big as POM-poms.
Parotitis
Orchitis
Meningitis (aseptic)
123
Surface spikes are fusion proteins forming multinucleated giant cells, humans are natural hosts
Respiratory syncytial (multinucleated giant cells) virus
124
DOC for RSV, also given in HepC
Ribavirin
125
MABs and their respective diseases
Palivizumab - RSV
Sevirumab - CMV
Omalizumab - Asthma
Ibalizumab - HIV
126
In infants, causes pneumonia and bronchiolitis, with severe disease due to immunologic cross reaction with maternal antibodies
RSV
127
Causes laryngotracheobronchitis (croup) - inspiratory stridor, cough, hoarseness, steeple sign on x-ray (subglottic stenosis)
Parainfluenza Virus 1 and 2
128
Moves by axonal transport to CNS, histopathologic finding of Negri bodies
Rabies
129
Phase in rabies where there are periods of mental aberration but with lucid intervals, eventual prominent brainstem dysfunction
Encephalitic phase
130
Diagnostic tests for rabies
Fluorescent Ab testing for CSF (late, cannot be from vaccine since these do not cross the BBB)
RT-PCR on fresh saliva
Skin biopsy sample (brain is ideal)
Absence of negri bodies does not rule out rabies
131
Only vaccine that is routinely used post-exposure
Rabies vaccine
| Recall: WHO Guidelines for PEP for Rabies
132
Caused by Corona virus, binds to ACE-2 receptor, non-cavitary "ground glass" infiltrates on x-ray, atypical pneumonia rapidly progressing to ARDS
Severe Acute Respiratory Syndrome (SARS)
133
5 serotypes, gold standard for diagnosis is PCR, breakbone fever, hemorrhagic shock due to cross-reacting antibodies during second infection
Dengue Virus
134
Most prevalent blood-borne pathogen
Hepatitis C
135
Most common indication for liver transplantation
Hepatitis C
136
DOC for chronic Hep C
Peginterferon
| Ribavarin
137
DOC for acute Hep C
Interferon
138
Main cause of essential mixed cryoglobulinemia
Hepatitis C
139
Responsible for autoimmune reactions such as thyroiditis, autoantibodies, MPGN, porphyria cutanea tarda, and DM
Hepatitis C
140
Togaviridae, 3-day maculopapular rash and posterior LAD
Rubella
141
Rubella causes 2 disease entities
German Measles
| Congenital Rubella Syndrome
142
5 Bs of Congenital Rubella Syndrome
```
Bulag (cataracts)
Bingi (sensorineural deafness)
Bobo (mental retardation)
Butas ng puso (PDA)
Blueberry muffin baby
```
143
Diploid retrovirus
HIV
144
Proteins and their respective functions as encoded by HIV gene: gag
p24, p7 - nucleocapsid
| p17 - matrix
145
Proteins and their respective functions as encoded by HIV gene: pol
reverse transcriptase - transcription of RNA genome into DNA (RNA-dependent DNA polymerase)
protease - cleaves precursor polypeptides
integrase - integrates viral DNA into host cell DNA
146
Proteins and their respective functions as encoded by HIV gene: env
gp 120 - attachment to CD4 protein, antigenicity changes rapidly
gp 41 - fusion with host cell
147
Group-specific antigen that is located in the core, therefore conserved and is an important marker for serologic HIV testing
p24
148
Most immunogenic region of gp120
V3 loop
149
High mutation rate in HIV is due something that is lacking in reverse transcriptase
Lacks proofreading mechanism
150
Phase of HIV infection where there is rapid viral replication but HIV test is negative
Phase 1 - Window Period
151
Phase of HIV infection where there is peak in viral load, positive HIV test, mild flu-like illness lasting 1 to 2 weeks
Phase 2- Seroconversion
152
Phase of HIV infection where patient is asymptomatic, CD4 goes down, lasts up to 15 years
Phase 3 - Latent Period
153
HIV is acquired
Phase 0 - Infection
154
CD4 count in Phase 4 - Early Symptomatic
500 to 200
Lasts 5 years, mild mucocutaneous, dermatologic and hematologic illness
155
CD4 count is less than 200, AIDS-defining illnesses develop
Phase 5 - AIDS
156
AIDS-Defining Illnesses
| CD4 Count < 500
M. tuberculosis - Disseminated TB
HSV - HSV Esophagitis
C. albicans - Esophageal candidiasis
HHV 8 - Kaposi sarcoma
157
AIDS-Defining Illnesses
| CD4 Count < 200
```
P. jiroveci - PCP
T. gondii - Cerebral toxoplasmosis
C. neoformans - Meningoencephalitis
C. immitis - Coccidiodomycocis
C. parvum - Chronic diarrhea
EBV - Burkitt's, HL, NPCA
```
158
AIDS-Defining Illnesses
| CD4 Count < 50
M. avium - invasive pulmonary disease
H. capsulatum - histoplasmosis
CMV - CMV retinitis
159
Basis of prognostication in HIV
Plasma viral load through PCR
160
Test for definitive diagnosis for HIV
Western blot analysis
| Antibodies will bind to gp 41 or p24 protein
161
Test for presumptive diagnosis for HIV
ELISA
162
Components of HAART
2 Nucleoside inhibitors = Zidovudine and Lamivudine
| 1 Protease inhibitor = Indinavir
163
What sometimes happens to HIV patients started on HAART with co-infection of HepB, HepC and MAC/MAI?
Immune Reconstitution Inflammatory Syndrome (IRIS)
Synonym(s): Immune Reconstitution Syndrome, Immune Restoration Disease
In HIV infection, an exaggerated inflammatory reaction to a disease-causing microorganism that sometimes occurs when the immune system begins to recover following treatment with antiretroviral (ARV) drugs. Immune reconstitution inflammatory syndrome (IRIS) occurs in two forms: "unmasking" IRIS refers to the flare-up of an underlying, previously undiagnosed infection soon after antiretroviral therapy (ART) is started; "paradoxical" IRIS refers to the worsening of a previously treated infection after ART is started. IRIS can be mild or life-threatening.
164
Mutation in this gene interferes with the function of gp 120 viral protein in HIV
CCR 5
| Patient with the mutation is found to be immune to HIV.
165
DOC for prophylaxis agains mycobacterium avium intracellulare complex
Azithromycin + Ethambutol
166
Patient previously had PCP, now has ring-enhancing lesions on brain CT. What organism is responsible?
T. gondii
167
The only live vaccine that can be given to HIV patients
MMR vaccine
168
Histopathologic finding of malignant T cells with flower-shaped nucleus
Human T-Cell Lymphotrophic Virus (HTLV)
169
Zika and Ebola virus origins
Zika - Uganda (1947 in monkeys, 1952 in humans)
| Ebola - Zaire (1976)
170
Thalamic infarcts on CT scan, vector is Culex, most common cause of epidemic encephalitis
Japanese encephalitis
