Microbiology:Virology Flashcards
(148 cards)
1
Q
What is the term for viral exchange between 2 chromosomes within regions of homology?
A
Recombination
2
Q
What is the term for when viruses with segmented genomes exchange segments?
A
Reassortment
3
Q
What is the term for when one of 2 viruses that infect a cell has a non functional protein, but the protein is supplemented by the other virus?
A
Complementation
4
Q
What is the term for when there is infection of a cell by 2 viruses and the genome of virus A is coated by proteins from virus B, giving it the infectious characteristics of virus B (for one generation)?
A
Phenotypic mixing
5
Q
When should live attenuated viruses not be given?
A
To immunocompromised people or their close contacts
6
Q
What are the live, attenuated vaccines?
“Live! See Small Yellow Chickens get vaccinated with Sabins and MMR! Incredible!”
A
Smallpox Yellow fever Chickenpox (VZV) Sabin's polio virus MMR Influenza (intranasal)
7
Q
What are 4 killed vaccines?
RIP Always
A
Rabies
Influenza (injected)
Polio (salk)
HAV
8
Q
What is the key recombinant vaccine?
A
HBV (recombinant HBsAg)
types 6, 11, 16, 18)
9
Q
All DNA viruses have dsDNA genomes except: (1)
All are linear except: (3)
A
Parvoviridae (B19) (part-of-a-virus)
Papilloma, polyoma, hepadnavirus (circular)
10
Q
All RNA viruses are ss except for:
A
Reoviridae (repeatOvirus)
11
Q
What are the + RNA viruses?
A
"went to a Retro Toga party, drank Flavored Corona and at Hippy California Pickles: Retrovius Togavirus Flavivirus Coronavirus Hepevirus Calicivirus Picornavirus
12
Q
What naked viral genomes are infective (generally)?
A
dsDNA (except pox and HBV)
+ ssRNA (same as mRNA)
** -ssRNA and ssDNA need polymerases in the complete virion to be infectious
13
Q
All viruses are haploid (1 copy of DNA or RNA) except:
A
Retroviruses (2 identical ssRNA molecules)
14
Q
All DNA viruses replicate in the nucleus except
All RNA viruses replicate in the cytoplasm except
A
Poxvirus (carries its own DNA-dep RNA polymerase)
Influenza virus and retrovirus
15
Q
What viruses are naked?
A
PAPP smears and CPR to a naked Heppy Papillomavirus Adenovirus Picornavirus Polyomavirus Calicivirus Parvovirus Reovirus Hepevirus
16
Q
What is the exception to the rule that most enveloped viruses acquire their envelopes from the plasma membrane?
A
Herpesvirus acquires envelopes from the nuclear membrane
17
Q
Most DNA viruses are icosaherdal, except
A
Poxvirus (complex)
18
Q
What virus causes oral (some genital) lesions, spontaneous temporal lobe encephalitis, and ketatoconjunctivitis?
Envelope? DNA structure?
A
HSV-1
Enveloped
DS and linear
19
Q
What virus causes genital lesions (some oral)?
Envelope? DNA structure?
A
HSV-2
Enveloped
DS and linear
20
Q
What virus causes chickenpox, shingles?
Envelope? DNA structure?
A
VZV or HHV-3
Enveloped
DS and linear
21
Q
What virus causes Burkitt’s lymphoma and Hodgkin’s lymphoma?
Envelope? DNA structure?
A
EBV or HHV-4
Enveloped
DS and linear
22
Q
What virus causes AIDs retinitis, infection in transplant patients, and congenital defects?
Envelope? DNA structure?
A
CMV or HHV-5
Enveloped
DS and linear
23
Q
What virus causes roseola, or exanthem subitum?
Envelope? DNA structure?
A
HHV-6
Enveloped
Linear
24
Q
What virus is a less common cause of roseola than HHV-6?
Envelope? DNA structure?
A
HHV-7
Enveloped
Linear
25
What virus is associated with Kaposi's sarcoma?
| Envelope? DNA structure?
HHV-8 (KSHV)
Enveloped
Linear
26
What does the hepadnavirus vaccine contain?
HBV surface antigen
27
Is hepadnavirus enveloped? Genome structure?
Yes
| DS and partially circular
28
What virus causes febrile pharyngitis, acute hemorrhagic cystitis, pneumonia, and conjunctivitis (pink eye)?
Envelope? DNA structure?
Adenovirus
Naked
DS and linear
29
```
What virus causes:
Aplastic crises in sickle cell disease
RBC destruction and hydrops fetals
Pure RBC aplasia
Rheumatoid arthritis-like sx in adults
```
Parvovirus (also erythema infectiosum)
30
Is parvovirus enveloped? Genome structure?
No
SS and linear (-)
**only ssDNA virus
31
What does papillomavirus cause?
| Envelope? DNA structure?
1,2,6,11 cause warts
CIN and cervical cancer
Naken
DS and circular
32
What are the subtypes of polyomavirus and what are their medical importances?
JC virus: progressive multifocal leukoencephalopathy in HIV
| BK virus: targets the kidney (seen in transplant patients)
33
Do polyomaviruses (JC and BK) have an envelope? Genome structure?
Naked
| DS and circular
34
What virus causes molluscum contagiosum (flesh colored dome with central dimple)? What other diseases does it cause?
Poxvirus
| Smallpox and vaccinia (cowpox)
35
What virus aside from retrovirus has reverse transcriptase?
Hepadnavirus
36
What is the MCC of sporadic encephalitis in the US?
HSV-1 infection
37
What is the largest DNA virus?
| Envelope? DNA structure?
poxvirus
| enveloped, DS, and linear
38
Where is HSV-1 latent?
| Route of transmission?
Trigeminal ganglia
| Respiratory secretions and saliva
39
What are 4 diseases that VZV (HHV-1) can cause?
Chickenpox
Shingles
Encephalitis
Pneumonia
40
What strain of herpesvirus causes neonatal herpes?
| Where is it latent?
HSV-2
| Latent in sacral ganglia
41
Where is VZV latent? Transmission?
Trigeminal or DRG
| Respiratory secretions
42
Where is EBV (HHV-4) latent? Transmission?
latent B cells
| Respiratory secretions and saliva
43
What virus causes mononucleosis with a negative monospot test, pneumonia, retinitis, and congential infection?
CMV (HHV-5)
44
What is characteristic of cells of CMV?
| Where is the virus latent?
"Owl's eye" inclusions
| Latents in mononuclear cells
45
Forms of transmission of CMV (6)
```
Congenitial
Transfusion
Sexual contact
Saliva
Urine
Transplant
```
46
What virus causes roseola--high fevers for several days (may cause seizures), followed by a diffuse macular rash?
HHV-6
47
What virus leads to Kaposi's sarcoma in HIV patients?
HHV-8
48
What is the test of choice for HSV? What is an other test for HSV?
PCR
| Tzanck test: detect multinucleated giant cells (HSV-1 and 2, VZV)
49
What will be seen inside cells infected with HSV?
Intranuclear Cowdry A inclusions
50
What disease is characterized by fever, hepatosplenomegaly, pharyngitis, and lymphadenopathy (esp the posterior cervical nodes)?
Mononucleosis
51
What are the atypical lymphocytes seen in EBV infection?
Downey cells, which are CD+ T cells reacting against the infected B cells
52
What does a positive monospot test detect?
Heterophile antibodies
53
What malignancies is EBV associated with?
Hodgkin's
Endemia Burkitt's lymphoma
Nasopharyngeal carcinoma
54
What virus causes Colorado tick fever? #1 cause of fatal diarrhea in children? What viral family?
Coltivirus
Rotavirus
*Reovirus family*
55
Are reoviruses enveloped? RNA structure?
No
DS linear in 10-12 segments
**only dsRNA virus
56
What are the 5 picornaviruses?
| Is picornavirus envleoped? RNA structure?
```
Poliovirus
Echovirus
Rhinovirus
Coxsackie virus
HAV
(PERCH on a peak (pico)
** no, + linear
```
57
What picornavirus causes aseptic meningitis?
Echovirus
58
What picornavirus causes the common cold?
Rhinovirus
59
What picornavirus causes aseptic meningitis, herpagina (mouth blisters and fever), and myocarditis?
Coxsackievirus (also hand/foot/mouth disease)
60
What virus causes HEV? Envelope? RNA structure?
Hepevirus
| No, +ss
61
What family of virus is norovirus, which causes viral gastroenteritis?
Envleoped? RNA structure?
Calicivirus
| No +ss
62
What family of virus causes HCV, yellow fever, dengue, St. Louis encephalitis, and West Nile?
Enveloped? RNA structure?
Flavivirus
| Yes +ss
63
What family of viruses causes rubella and eastern/western encephalitis?
Enveloped? RNA structure?
Togaviruses
| Yes +ss
64
What are the two important retroviruses and what do they cause?
Enveloped? RNA structure?
HIV-AIDS
HTLV-T cell leukemia
yes +ss
65
What are the two diseases caused by coronavirus?
| Enveloped? RNA structure?
Common cold
SARS
yes +ss
66
What is the key orthomyxovirus?
| Enveloped? RNA structure?
Influenza virus
| yes -ss (8 segment)
67
What are the 4 key paramyxoviruses?
Parainfluenza: croup
RSV: bronchiolitis in babies
Measles
Mumps
68
What drug is used for tx of RSV infection in babies?
Ribavirin
69
Are paramyxoviruses enveloped? RNA structure?
Yes
| - ss
70
What disease does rhabdovirus cause?
| Enveloped? RNA structure?
Rabies
| yes -ss
71
What doe the ebola and marburg filoviruses usually cause?
| Enveloped? RNA structure?
Hemorrhagic fever that is often fatal
| Yes -ss
72
What family of virus do lymphocytic choriomeningitis virus and lassa fever virus (encephalitis) belong to?
Enveloped? RNA structure?
Arenavirus
| Yes -ss in 2 segments (circular)
73
What family of viruses causes california encephalitis, sandly/rift vally fevers, crimean-congo hemorrhagic fever, and hantavirus induced hemorrhagic fever and pneumonia?
Enveloped? RNA structure?
Bunyavirus
Yes
ss and -, circular in 3 segments
74
What is a "defective virus" that requires co-infection with HBV?
Enveloped? RNA structure?
Delta virus
| ss and -, circular
75
What are the viruses that require RNA-dep RNA polymerase in their virion? (negative stranded)
```
Arenavirus
Bunyavirus
Paramyxovirus
Orthomyxovirus
Filovirus
Rhabdomivrus
**Always Bring Polymerase Or Fail Replication
```
76
What are the 4 families of segmented viruses? (all RNA)
```
Bunyaviruses
Orthomyxoviruses (influenza)
Arenaviruses (lassa and LCMV)
Reoviruses (coltivirus and rotavirus)
**BOAR
```
77
What are the picornaviruses?
```
Poliovirus
Echovirus
Rhinovirus
Coxsackievirus
HAV
```
78
All picornaviruses can cause aseptic meningitis except rhinovirus and HAV, and all are enteroviruses except rhinovirus. Why cant rhinovirus infect the GI?
It is acid-labile, and is destroyed by stomach acid
79
What is yellow fever virus transmitted by?
| What are the sx of yellow fever?
Aedes mosquitos
| High fever, black vomitus, and jaundice
80
What is the most important global cause of infantile gastroenteritis?
Rotavirus (segmented dsRNA virus, reovirus)
| **major cause of diarrhea in the winter, esp day care, kindergarten
81
What causes the diarrhea in rotavirus infection?
Villous destruction with atrophy leads to decreased absorption of Na and loss of K
82
What is an enveloped, negative, ssRNA virus with a 8-segment genome?
Influenza virus (an orthomyxovirus)
83
What components of influenza virus promote entry and promote progeny virion release?
Hemagglutinin
| Neuraminidase
84
What happens with genetic SHIFT?
Reassortment of the viral genome; segments under go high frequency recombination
Causes pandemics
85
What happens with genetic DRIFT?
Minor changes due to random mutation
| Causes epidemics
86
What presents with fever, postauricular adenopathy, lymphadenopathy, arthralgias, and a fine truncal rash that starts at the head and moves down?
```
Rubella virus (a togavirus)
aka German Measles
```
87
What group of viruses includes parainfluenza, mumps, measles, and RSV?
Paramyxovirus
88
What surface protein do all paramyxoviruses (measles, mumps, RSV, parainfluenza) express?
Result?
F (fusion) protein
| Causes respiratory epithelium to fuse and form multinucleated cells
89
What drug prevents pneumonia causes by RSV infection in premature infants?
Palivizumab (monoclonal antibody against F (fusion) protein)
90
What infection is characterized by Koplik spots (red spots with a blue-white center on buccal mucosa) and a descending maculopapular rash?
Measles virus
91
What are three possible sequelae of a measles virus infection?
Subacute sclerosing panencephalitis (SSPE)
Encephalitis
Giant cell pneumonia
92
How can the rash of measles virus be distinguished from rubella?
Includes the hands and feet, unlike the truncal rash seen in rubella
93
Koplik spots will be seen how long before the rash spreads head to toe in Measles?
1-2 days before
94
What virus presents with partotitis, orchitis, and aspetic meningitis (POM-poms)?
Mumps
95
What are negri bodies, and when are they seen?
Characteristic cytoplasmic inclusions in neurons, usually seen in the Purkinje cells of the cerebellum
Rabies infection
96
What is postexposure tx for rabies?
Wound cleansing
Vaccination
+/- rabies immune globulin
97
What happens upon inoculation with rabies virus?
Long incubation period of weeks to months
| Travels to the CNS is a retrograde fashion up nerve axons
98
What is seen in the three stages of rabies?
1. Fever and malaise
2. Agitation, photophobia, hydrophobia
3. Paralysis, coma, death
99
What are the MC sources of rabies
Bats, raccoons, and skunks more than dogs
100
What two hepatitis viruses have fecal-oral transmission and short incubation time? Which one is more likely to be spread via water?
HAV and HEV
| HEV
101
Which herpes virus is a RNA picornavirus?
HAV
102
Which herpes virus is a RNA flavivirus?
HCV
103
Which herpes virus is a DNA hepadnavirus?
HBV
104
Which herpes virus cant be acquired alone?
HDV
105
Which herpes virus is a RNA hepevirus?
HEV
106
Which herpes virus has high mortality in pregnant women?
HEV
107
Which herpes virus is often transmitted by IVDU?
HCV
108
What two herpes viruses increase the risk for HCC? By what mechanism?
HBV: integrates into host genome and acts as an oncogene
HCV: chronic inflammation
109
What is the best test to detect active hepatitis A?
| Prior hepatitis A infection or vaccination?
Anti-HAV IgM
| Anti HAV IgG
110
What antigen indicates current hep B infection?
HBsAg
111
What antibody indicates immunity to hep B?
Anti-HBs
112
What antigen indicates that natural exposure has occurred?
HBcAg (not seen with vaccination)
113
What does anti-HBc IgM indicate? IgG?
IgM: acute or recent infection
IgG: prior exposure or chronic infection
114
What is the window period in hep B infection? What is positive on serology
Period between loss of the HBsAg and development of anti-HBs
| Anti HBc and anti HBe will be positive
115
What do HBeAg and anti-HBe indicate?
HBeAg: contagious
| anti-HBe: non-contagious
116
What is the only virus with a diploid genome?
HIV (2 molecules of RNA)
117
What are the three structural genes of HIV?
1. env (gp120 and gp41)
2. gag (p24)
3. pol
118
What are gp120 and gp41 formed from? What is their role?
Cleavage of gp160
gp120 for attachment
gp41 for fusion and entry
119
What is the capsid protein of HIV?
p24 (encoded by gag)
120
What are the three proteins encoded by pol?
Reverse transcriptase
Aspartate protease
Integrase
121
What molecules does HIV bind on T cells?
CD4
| CCR5 (early) or CXCR4 (late)
122
What molecules does HIV bind on MØs?
CD4
| CCR5
123
What is the result of homozygous and heterzygous CCR5 mutations on HIV infection?
Homozygous: immunity
Hetero: slower course
124
What is used for HIV screening?
| Confirmation?
```
ELISA (sensitive, high FP rate)
Western blot (specific)
```
125
What is the HIV PCR test used for?
Eval viral load--> high load mean bad prognosis
| Monitor effects of therapy
126
How is AIDS diagnosed?
< 1.5
127
When are ELISA and western blots looking for antibodies to HIV proteins often falsely negative?
Falsely positive?
First 1-2 mo of infection
| Infants born to infected mothers (anti-gp120 can cross the placenta)
128
At what CD4 counts does immunocompromise occur? When do AIDS-defining illnesses emerge?
<200
129
Low grade fevers, cough, hepatosplenomegaly, tongue ulcer and oval yeast cells in MØs seen in HIV patient, think:
Histoplasma capsulatum
**usually only causes pulm sx in normal patients
CD4 <100
130
Fluffy, white, cottage cheese lesions and pseudohyphae, seen in HIV patient, think:
Candida albicans
| Oral when CD4 <100 PAINFUL
131
Superficial vascular proliferation and biopsy showing PMN infiltration in HIV patient, think:
Bartonella henselae (bacillary angiomatosis)
132
Chronic, watery diarrhea and acid-fast cysts in the stool in HIV patient, think:
Cryptosporidium
| CD4 <200
133
Encephalopathy and signs of demyelination in HIV patient, think:
JC virus reactivation
| CD4<200
134
Abscesses and ring-enchancing lesions on imaging in HIV patient, think:
Toxoplasma gondii
| CD4 < 100
135
Meningitis and india ink stain revealing yeast with broad budding and thick capsule in HIV patient, think:
Cryptococcus neoformans
| CD4<50
136
Cotton-wool spots on fundoscopic exam and esophagitis in HIV patient, think:
CMV
| CD4<50
137
What neuro disorder is DIRECTLY associated with HIV?
Dementia
138
Superficial neoplastic proliferation of vasculature with biopsy revealing lymphocytic inflammation in HIV patient, think:
HHV-8, Kaposi's sarcoma
| **distinguish from Bartonella henselae by lymphocytic infiltrate rather than PMN infiltrate
139
Hairy leukoplakia on lateral tongue in HIV patient, think:
EBV
140
Non-Hodgkin lymphoma (large cell type) in the oropharynx (Waldeyers ring) in HIV patient, think:
EBV
141
Squamous cell carcinoma around the anus (MSM) or cervix in HIV patient, think:
HPV
142
Primary CNS lymphoma in HIV patient, think association witih:
EBV
143
Interstitial pneumonia and biopsy revealing intranuclear "owl eye" inclusions in HIV patient, think:
CMV
144
Pleuritic pain, hemoptysis, and infiltrates on imaging in HIV patient, think:
Aspergillus fumigatus (invasive)
145
Pneumonia with CD4 count <200 in HIV patient, think:
Pneumocystis jirovecii
146
Tb-like disease with CD4 count <50 in HIV patient, think:
Mycobacterium avium-intracellulare
147
What is the mechanism behind prion disease?
| Result of accumulation?
Normal cellular protein (PrP^c) is converted to beta pleated form (PrP^sc)
Spongiform encephalopathy, demantia, ataxia, and death
148
What are examples of sporadic, inherited, and acquired prion disease?
Sporadic: Creutzfeldt-Jacob disease
Inherited: Gerstmann-Straussler-Scheinker syndrome
Acquired: Kuru
