Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > 3.34 > Flashcards

3.34 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Paramyxoviruses (Family = Paramyxoviridae) Chapter 34

Species (4)

A

measles virus
mumps virus
respiratory syncytial virus (RSV)
parainfluenza viruses

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

Rhabdoviruses (Family = Rhabdoviridae) Chapter 35

Species: (1)

A

rabies virus

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

Orthomyxoviruses (Family = Orthomyxoviridae) Chapter 36

Species: (1)

A

influenza viruses A, B and C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q 
Paramyxoviruses
characteristics (4)
A

Helical nucleocapsid
Pleomorphic envelope (variable shape)
Hemagglutinin (measles virus) on envelope binds sialic acid on cell surface glycoproteins
measles virus binds CD46 protein present on most cells
minus stranded RNA genome

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

minus stranded RNA genome

=

A

one segment of RNA (~16,000 bases in length)

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

Paramyxovirus replication

A

Virus brings in RNA polymerase which transcribes minus RNA
into plus RNAs (full length and mRNAs)
Replication is cytoplasmic

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

Measles virus (~— nt –strand RNA genome)

A

16000

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

hemagglutinins -

A 
envelope glycoproteins
attachment proteins (bind virus to host cells)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

F protein -

A

causes membranes to fuse together
role in viral entry into cells
expression on infected cells causes cell-cell fusion
Giant cells (syncytia)

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

All paramyxoviruses can induce — formation

A

syncytia

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

Measles (Rubeola)

characteristics (3)

A

• caused by measles virus
• enters body through
respiratory tract
• extremely contagious

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

Measles (Rubeola)
— involvement (partly, inflammation due to host response)
humoral and cellular immune responses modulate outcome

A

skin

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

Measles (Rubeola)

3 Cs=

A

cough, coryza,
conjunctivitis
Also morbilliform appearance
(rash = exanthem)

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

Coryza is a word describing the symptoms of a

A

head cold. It
describes the inflammation of the mucous membranes lining
the nasal cavity which usually gives rise to the symptoms of
nasal congestion and loss of smell, among other symptoms.

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

Measles (Rubeola)

complications (3)

A 
– Pneumonia (giant cell pneumonitis)
– Bacterial superinfections of middle ear
and lung
– pneumococci, staphylococci, and
meningococci
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Measles (Rubeola)

• subacute sclerosing panencephalitis (1)

A

– rare progressive degeneration of central
nervous system caused by a type of
measles virus

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

Measles (Rubeola)

• treatment, prevention, and control (2)

A 
– symptomatic/supportive therapy
– attenuated measles vaccine
• MMR vaccine (measles, mumps,
rubella)
• Live Measles vaccine - 1993
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Mumps

• caused by (3)

A 
mumps
virus
– Paramyxovirus
pleomorphic,
enveloped virus
– helical nucleocapsid
– negative strand RNA
(~15,000 nt)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q 
mumps 
clinical manifestations (3)
A

– develop 16-18 days after infection
– fever, and swelling and tenderness of salivary glands
– complications include meningitis and orchitis
(inflammation of testis)

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

mumps

tx

A

– live, attenuated vaccine (MMR)

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

Respiratory syncytial virus

characteristics (3)

A

minus stranded RNA
genome = one segment of RNA
enveloped

22
Q

Respiratory syncytial virus

G protein binds

A

host cells

instead of a hemagglutinin

23
Q

Respiratory syncytial virus

F protein -

A

causes membrane fusion

syncytia formation

24
Q

Respiratory syncytial virus

virus enter respiratory epithelial cells, then spreads

A

downward

along the respiratory mucosa

25
Q

Respiratory syncytial virus

no clinically significant spread to distant sites (3)

A

necrosis of epithelial cells
infiltration of lymphocytes
increased mucous production

26
Q

Respiratory syncytial virus (RSV) (2)

A

• considered to be most dangerous respiratory infections
in young children
• spread by hand contact and respiratory secretions

27
Q 
RSV 
clinical manifestations (3)
A

– acute onset of fever, cough, rhinitis, and nasal
congestion
– often progresses quickly to severe bronchiolitis and
pneumonia
host response may account for most serious

28
Q

• bronchiolitis -

A

bronchiole obstruction that can

lead to respiratory failure

29
Q

RSV

tx

A

– rapid immunologic tests

30
Q

Rabies

• caused by — virus (3)

A

rabies

– negative strand RNA virus
– highly neurotropic

31
Q

Rabies

transmitted by: (3)

A

– bites of infected animals
– aerosols in caves where bats roost
– contamination of scratches, abrasions, open wounds,
or mucous membranes with saliva of infected animals

32
Q 
Rabies virus (Lyssavirus) 
characteristics (3)
A

minus stranded RNA
genome = one segment of RNA (~12,000 bases in length)
enveloped, bullet shaped virus
replication is entirely cytoplasmic

33
Q

incubation can be up to – months after
virus enters body
depends on size of: —
location of bite: — bite has shorter incubation

A

12
inoculum
face

34
Q

Negri bodies

A

masses of nucleocapsids in cytoplasm
seen in brain tissue of 70-90% of infected
humans

35
Q 
rabies 
clinical manifestations (5)
A

clinical manifestations
– begin 2 to 16 weeks after exposure
– pain or paresthesia at wound site, anxiety, irritability,
depression, fatigue, loss of appetite, fever, and
sensitivity to light and sound
– Hydrophobia
– quickly progresses to paralysis
– death results from destruction of regions of brain that
regulate breathing

36
Q

Hydrophobia:

A

contractions of muscles involved in

swallowing (sometimes sight of water elicits this)

37
Q

rabies

tx (3)

A

– Passive administration of antibody (antiserum or
immunoglobulin) (human rabies immune globulin = HRIG
collected from immunized persons)
– postexposure vaccination
– preexposure vaccination of individuals with high risk of
exposure, dogs, and cats

38
Q

Orthomyxoviruses (Family = Orthomyxoviridae) Chapter 36 (3)

A

Genus: Influenzavirus - influenza virus A, B and C
minus stranded RNA
enveloped

39
Q

Orthomyxoviruses

genome=

A

8 segments of RNA (for influenza viruses A and B)

7 segments of RNA (for influenza virus C)

40
Q

cap-snatching -

A

uses 5 end of host mRNA to prime viral mRNA synthesis

Random packaging of the 8 segments (11 segments packaged per virion)

41
Q 
Surface spikes (peplomers)
hemagglutinin (HA)
A

attachment to host cell surface (prior to entry)
binds to sialic acid on epithelial cell surface
promotes membrane fusion (viral-cellular)
binds/aggregates RBCs
elicits protective neutralizing antibody
response

42
Q

neuraminidase (NA)

A

release of virus from envelope

cleaves sialic acid (NA has enzymatic activity)

43
Q

Typical flu symptoms (fever, headache, muscle aches, malaise) due to —

A

interferon induction

44
Q

rabies tx (2)

A

–Treat with amantidine,
rimantidine (A strain only);
ribavirin (A and B)
–inactivated virus vaccine

45
Q

Antigenic shifts in influenza virus are caused by
— of viral genomic fragments during a
mixed infection by two different influenza viruses

A

reassortment

46
Q

Reassortment creates an

A 
influenza virus that can
infect humans but has a
hemagglutinin from the
animal influenza virus
strain. (H3 vs. H2 in
original human infleunza
virus strain)
47
Q

Changes in influenza virus surface proteins
(hemagglutinin and neuraminidase) due to
— that occur during viral
replication is called antigenic drift.

A

point mutations

48
Q

Antigenic shifts in influenza virus are caused
by reassortment of viral genomic fragments
Pigs play an important role as a “mixing vessel”

A

for influenza viruses from humans, birds, and
pigs. This is because pigs can become infected
by these different influenza viruses.
Example:
Diagram of the origin of a new human virus
with a shift from H3N2 to H5N1.
Pigs were infected with a duck influenza virus,
and another set of pigs with the human
influenza virus.
At some time, one pig underwent mixed
infection with both viruses.
The resulting virus created by reassortment of
the viral gene segments could be transmitted
to and infect humans. In this example,
genomic segments from the duck virus
contribute the genes for hemagglutinin and
neuraminidase, shifting the original human
virus from H3N2 to H5N1.

49
Q

1918 flu pandemic: “spanish influenza”

characteristics (2)

A

killed 50 million world-wide

victims usually young and previously healthy

50
Q

Likely killed via a “cytokine storm” in victims with strong immune systems

A

unchecked positive feedback loop between cytokines and cellular response
result: too many immune system cells activated in an single space à tissue damage

51
Q

H1N1 virus:

A

genome recovered in 1997 from victim in permafrost grave in Alaska
Sequencing showed the virus originated in birds and mutated to be infectious in humans

Microbiology (42 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions