Exam 4 Flashcards
(122 cards)
1
Q
What does viruses require for cell replication?
A
A cell. Viruses hijack cellular machinery.
2
Q
Two primary type of viruses:
A
RNA and DNA
3
Q
Types of RNA viruses
A
Positive
Negative
Reovirus
Retrovirus
4
Q
Types of DNA viruses
A
Double Stranded
Single Stranded
5
Q
Proteins which surround viral genome?
A
Capsides
6
Q
Types of Capsids
A
Icosahedral and Helical
7
Q
20 Sided spheroid comprised of triangle made of capsomers
A
Icosahedral
8
Q
Protein capsomer bound to RNA
Coiled in Helix
Spherical Shape
A
Helical
9
Q
Capsid is encased in lipid bilayer of
A
Envelope
10
Q
Does survivability increase or decrease outside of hosts?
A
Decrease
11
Q
RNA Virus: Positive Strand Function Process
A
Functions like mRNA
Viral RNA undergoes translation to produces viral proteins and enzymes necessary to produce new viral particles
12
Q
RNA Virus: Negative Strand Function Process
A
RNA undergoes transcription via RNA dependent RNA polymerase.
Then mRNA undergoes translation, produces proteins and enzymes necessary to produce new viral particles.
13
Q
RNA Virus: Reovirus Structure
A
Double Stranded RNA virus
14
Q
RNA Virus: Retrovirus Function Process
A
Part of Positive Stranded Family
RNA reverse transcribed using viral reverse transcriptase to DNA.
DNA can integrate into host cell.
DNA undergoes transcription to produce mRNA.
mRNA undergoes translation to produce proteins and enzymes.
15
Q
DNA Viruses mRNA are transcribed off of the positive or negative strand?
A
Negative
Then translated to structural proteins & enzymes.
16
Q
Viral Life Cycle STEPS
A
Adsorption and penetration
Uncoating of the virus
Synthesis of viral products including DNA, RNA, protein
Release of viral particles from the host cell
17
Q
RNA Virus:: Positive Stranded Replication
A
Host cell ribosome produces virus structural proteins, viral RNA polymerase.
RNA polymerase creates negative template for viral RNA.
Proteins and RNA assemble and allow the virus to release.
18
Q
RNA Virus:: Negative Stranded Replication
A
Viral RNA has to be TRANSCRIBED before it can do anything!!
Positive strand of viral RNA is essentially mRNA.
RNA polymerase produces negative strand of RNA for future virions.
Structural proteins, enzymes and RNA assembled for release.
19
Q
Retrovirus Example?
A
HIV
20
Q
Retrovirus Viral Replication
A
VIRUS IS INTEGRATED INTO THE HOST GENOME!!!!
Viral RNA undergoes reverse transcription.
Viral DNA gets integrated into host genome.
Host cell machinery is hijacked to produce viral structural proteins, viral enzymes, and viral RNA.
21
Q
DNA Virus Replication
A
ALWAYS OCCUR IN THE NUCLEUS!!!
Transcription & Translation of proteins for DNA replication.
Proteins lead to replication of viral DNA.
Transcription events result in the production of structural proteins.
Progeny DNA and structural proteins can assemble.
22
Q
Release of the Naked Virions Occurs By
A
Cell Lysis
Reverse Phagocytosis
23
Q
Release of Enveloped Virions Occurs By
A
Bud through Golgi, nuclear membrane, cell membrane.
Bring a piece of the cell membrane with it as envelope.
24
Q
Outcomes for host cell
A
Death
Transformation
Latent Infection
Chronic Slow Infections
25
Infection results in activation/introduction of oncogenes, resulting in uncontrolled or uninhibited cell growth
Transformation
26
Virus persists in an inactive state for extended amount of time but is asymptomatic. Can be reactivated at a later point in time
Latent Infections
27
Individual viruses have affinity for receptors on cell surfaces, which determines which cells they are capable of infecting (Can be broad or specific for 1 cell)
Viral Tropism
28
Evasion from the immune system (prevents the immune system from eliminating the environment)
Latency
Mutation
Interference/Subversion
29
Produce only a few viral proteins and can persist in cells for an extended amount of time
Latency
30
Surface protein of virus can mutate to evade detection to host immune system
Mutation
31
Blocking apoptosis, decrease interferon expression
Interference/Subversion
32
SARS-CoV-2 is transmitted
Respiratory Droplet
33
SARS-CoV-2 Structure
Positive Stranded, Enveloped RNA virus
34
SARS-CoV-2 can cause
bronchitis and lung inflammation
35
R0 is the
reproduction number for a virus
1 = 1 person will spread to 1 person
> 1 = cases increase
< 1 = cases decrease
36
Class:: Orthomyxovirus
Influenza
37
Contagious respiratory illness which infects the nose, throat, & lungs
Influenza
38
Influenza is transmitted
by tiny droplets when people cough or sneeze
39
Influenza Structure
Single stranded, Enveloped negative stranded RNA virus
40
Influenza Envelope is spiked with 2 glycoproteins called
Hemagglutinin and Neuraminidase
41
Binds to silica acid receptor (expressed on RBC and cell in upper respiratory tract)
Hemagglutinin
42
Cleaves Neuramic Acid (key part of mucin)
Neuraminidase
43
Flu that Infects Humans, Pigs, and Birds
| * Multiple species targets allows for rapid viral evolution & potential pandemic (antigenic shift & drift)
A
44
Flu that Infects Humans and Seals
B
45
Flu that infects only humans
C
46
Small mutations in glycoprotein (H and N)
| * Antigenic Drift or Shift?
Antigenic Drift
47
Major changes in glycoproteins
| * Antigenic Drift or Shift?
Antigenic Shift
48
* Virus which can infect one species transmitted to a different species
* Animal infected by two strains of influenza SIMULTANEOUSLY
Antigenic Shift
49
The flu is grown in fertilized ________
chicken eggs
50
Neuraminidase Inhibitors (prevent viral particles from budding off of infected cells and can be used for prophylaxis) and Baloxavir (decreases symptoms by 1 day) are
Drugs for influenza treatment
51
Enveloped, Single Stranded Negative RNA virus
| HA, NA part of the SAME glycoprotein spike
Paramyxoviridae
52
Paramyxoviridae primarly affects what population
Children
53
Paramyxoviridae (HPIV) can cause what?
Croup (upper airway infection which causes constriction of the airway; results in a barking seal-like cough)
54
Respiratory Syncytial Virus can cause
Pneumonia in young children (< 6 months)
55
RSV (Respiratory Syncytial Virus) can be spreaded by
Coughs/Sneezes or Doorknobs
56
Metapneumovirus
Second Most Common Cause of Lower Respiratory Infections
| Can cause croup like symptoms
57
Unsegmented, Enveloped, Negative Single Stranded RNA virus
Mumps Virus
58
Mumps replicated where?
Upper Respiratory Tract, Lymph Nodes
59
Mumps can been seen by
Pain, Tenderness, and Swelling in salivary glands
60
Complication of Mumps
Spontaneous abortion during first trimester of pregnancy
Men develop orchitis (painful swelling of testes)
Aseptic Meningitis
Pancreatic inflammation
61
Measles (Rubeola) is an acute viral respiratory disease likely transmitted from
Cattle to Humans
62
Measles can cause
High Fever, Mailaise, Cough, Coryza, Conjuntivitis, Koplik spots, and maculopapular rash
63
Visual Inspection, Antibody in Blood or Throat Swab, and RNA via PCR is diagnoses for what disease?
Measles
64
Sudden Illness with a mild to severe course
Flu Like Symptoms, leading to jaundice
Elevated AST, ALT, GGT, Alkaline phophatase
* Acute or Chronic Hepatitis
Acute
65
Asymptomatic for a long amount of time
Mildly elevated LFTs, enlarged tender liver
* Acute or Chronic Hepatitis
Chronic
66
NAKED Positive Stranded RNA virus with an icosahedral Capsid
| * Which Hepatitis Strand?
Hepatitis A
67
Hepatitis A Transmission
```
Fecal to Oral
- Infected Food Handler Contaminating Food
- Ingestion Contaminated Water
Close contact to infected people
Injection Drug Use
Previous Infection
```
68
Fever, Malaise, Diarrhea, Nausea, Abdominal Discomfort, Dark Colored Urine, Jaundice are signs of
HAV (Resolves in 1 week)
69
Hepatities A Treatment
Vaccine recommended for people traveling, now included in pediatric vaccination regimen
Can give serum immune globulin to active cases
USUALLY WILL CLEAR ITSELF BY 2 MONTHS
70
This Hepatitis Strand can cause Acute and Chronic Disease
B
71
Eveloped Icosahedral virus with DOUBLE STRANDED circular DNA
| *Which Hepatitis Strand?
B
72
Hepatitis B Antigens
HBsAg - Comprised Primarily of envelop and some capsied
*Antibodies to thise are PROTECTIVE to infection
HBcAg: core antigen
HBeAg - marker for active disease (mother to child transmission)
73
Cirrhosis, Fluminant are complications of what Hepatitis Strand?
B
74
Treatment & Prevention of Hepatitis B
Vaccination
* HBsAg, just surface antigen
* Part of Infant Infection Schedule & Health Care Providers
Interferon Tx
* Suppress DNA Levels (Given for 4 months)
Nucleoside/Nucleotide Analogs
75
LOW PRIORITY : Helical Capsid RNA virus which uses HBV envelope
Hepatitis D
76
Replication requires co-infection of a cell with both HBV, HDV
Heptitis D
77
Naked, Single Stranded Positive Sense Icosahedral RNA Virus
| *Which Hepatitis Strand?
E
78
Hepatitis Can Cause
Acute Hepatitis, Pancreatits, Thrombocytopenia
Vaccine Exists but ONLY IN CHINA
79
Enveloped Icosahedral Positive Stranded RNA Virus
Hepatitis C
80
Most Common Cause of Chronic Hepatitis
C
81
Transmission of Hepatitis C
Injectable Drugs, Needle Sticks, Mother to Child Transmission, Personal Care Items, Sexual Contact
82
Treatment of Hepatitis C
First Generation of Direct Acting Antiviral - 2011
Second Generation of DAA - 2014 $$$$
* Excellent Response
83
Primary Virus from of HIV
HIV-1
84
Slower Progression than HIV-1, lower plasma viral loads, and lower mortality
HIV-2 (most common in West Africa)
85
HIV-1 Transmission
Intercourse, Contaminated Needles, During Birth/Breasteding
86
Initial Spread of HIV-1 group M
Chimpanzee to Humans
Then 1981, young homosexual men with severe immune deficiency
87
HIV Viral Structure
Enveloped Virus with a dimerized singe stranded RNA core
** Contains viral enzymes including protease, reverse transcriptase, and integrase
Capsid has icosahedral symmetry
Expresses surfaces proteins (gp120 and gp41)
88
HIV Viral polyproteins
gag, pol, env
gag and env mutates at a very high rate
89
Cleaved by polymerase
Proteins inside the envelope involved in the structure
Antigenic, can be detected by immune system
*Which HIV viral polyprotein?
gag
90
MAJOR targets for antiretroviral drug development
Protese - cleases viral polyproteins
Reverse transcriptase - converts viral RNA to DNA
Integrase - Integrates viral DNA into the host genome
*Which HIV viral polyprotein?
pol
91
Two proteins associated with the viral envelope
* gp120 (head) and gp41 (stalk of envelope protein) = combine into gp160
Proteins are glycosylated
Bind to CD4 receptor, facilitates binding to host cells
*Which HIV viral polyprotein?
env
92
HIV Virology
gp120 binds to CD4 and a coreceptor
Can infect T cells, monocytes, and macrophages
Capsid enters cell, RNA is reverse transcribed
Viral DNA integrated into host genome
Viral DNA undergoes transcription, translation for viral proteins and viral genomic RNA
Viral particles generated
Viral capsids bud through cell, generating envelope
93
HIV Clinical Course
Untreated - Characterized by decline in CD4 cell count and increase in HIV RNA copies
1. Flu-Like Symptoms develop 1 month, while virus spreads to lymph nodes, then immune produces a response
2. 8 year clinical latency with no/few symptoms
3. AID, opportunistic infections develop
94
HIV/AIDS complications
Constituational Illness (Night Sweats, Fevers, Enlarged Lymph Nodes, Weight Loss)
Neurologic Disease
Malignancies (B cell lymphoma & Kapsoi's Sarcoma)
95
Opportunistic Infections
Bacteria (TB, MAC), fungi, Viruses (Herpes) and Protozoa
| Associated with decline in CD4 cell counts
96
Large, Enveloped Double Stranded DNA Viruses
Herpes
97
Herpes transmisison
Inoculation of mucutaneous sufaces, symptoms depend on site of infections
98
Oral Herpes (symptoms)
Blisters & Open Sores
99
Gingivostomatitis (swollen gums and mucous membranes, can be accompanied by inflammation & fever)
Herpetic Keratitis (Herpes infection of the eye)
Neonatal Herpes (infection via shedding of genital infection in the third trimester - seizures, psychomotor retardation, spasticity, blindness, learning disabilities, and death)
Herpetic Whitlow (Lesion on finger or thumb, swelling, reddening, tenderness of finger)
Disseminated Herpes (Occur in individuals who are immunocompromised)
Herpesvirus Encephalitis - primarly caused by HSV-1 (Confusion, increased WBC in CSF without bacteria or fungi - fevers, seizures)
are symtoms of?
Herpes
100
Varicella (Chickenpox) and Zoster (Shingles) can be caused by
Varicella-Zoster Virus
101
HIV/AIDS, Immunocomprimised individual are at risk of visceral dissmeination of chickenpox (Pneumonia, Hepatitis, Encephlaties), Preganat Women (in 3rd Trimester) are complications of
Chickenpox
102
Treatment of Chickenpox
Vaccine, Pain Killer (NO ASA), Calamine Lotion, Colloidal Oatmeal & Antiviral
103
Rash that develops on one side of face or body, develops into blisters.
Pain, intching and tingling before rash develops
Shingles
104
Treatment of Shingles
Zostava and Shingrix - Vaccination
Antiviral treatment can shorten the length and severityof the disease
Painkillers
Colloidal oatmeal & Calamine Lotion for the itiching
Hand washinb
105
Double Stranded Linear DNA Viruses with an Icosahedral Capsid and an evelope (Cytomegalovirus) (CMV)
Infected cells become enlarged
106
Congenital CMV can be serious during pregnancy becuase
Virus can be passed to baby
Can caus emiscarriage, premature birth, small size at birth, small head size, and seizures
More severe symptoms are hearing and vision loss, lack of coordination and muscle weakness
107
Human Herpesvirus 4
Epstein-Barr Virus
108
EBV can be transmitted by
saliva, blood and semen
109
EBV should be treated with support (fluids, rest, painkillers)
do not share drinks, food, personal intems, or kiss individuals
110
Poxviridae
| Box shaped DNA virus which replicateds in cytoplasm
Smallpox
111
Symptoms of Smallpox
Skin sores which fill with thick opaque fluid
112
Only virus eradicated by human. inoculate by puncturing skin.
Smallpox Vaccine
113
HPV - Double Stranded circular DNA virus WITHOUT an envelope
Infects basal epithelial cells
| Can cause warts
114
Rubella - Enveloped Single Stranded Positive RNA virus with icosahedral capsule - presented with
Red rash on face that spreads to the rest of the body for about 3 days - fever, HA, cough, runny nose
115
Vaccination provides life-long immunity and part of pediatric regiments (MMR) LIVE VACCINE (Do NOT give to pregnant women)
Rubella
116
Primary Host is Birds - Can be spread to humans and horses by mosquitos
West Nile Virus (positve stranded enveloped RNA virus)
- most common in elderly
- recovery can take weeks to months, some effects may be permanent
117
SARS-CoV-1 (Coronavirus) - Enveloped positive single stranded RNA virus can cause
Severe flu-like symptoms, fever, SOB and pneumonia
118
Transmission of SARS-CoV-1?
Pam civets or racoon drugs
119
Norovirus - Positive sense naked RNA virus can cause
diarrhea, vomiting, stomach pain
- Dehydration is common
- Develops 12-48 hours after exposure
120
Transmission of Norovirus
Fecal oral
121
Rhabdovirus (Rabies) - Enveloped negative sense RNA virus - replication occurs
at first site of infection, migrates to brain
122
Treatement of Rabies
Vaccine for Housepets (Series of 4 shots of rabies vaccine)
Wash Infected Area Immediately
Either
* Monitor source animal for 10 days
* Destroy source animal and check brain for negri bodiese
