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Flashcards in Intro to Medical Microbiology Deck (104)
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1
Q

In regards to host response evasion strategies, give an example of the “elicit minimal host response”

A

Herpes simplex virus remains latent in host cells for long periods without causing pathology

2
Q

In regards to host response evasion strategies, give an example of the “evade effects of host response”

A

mycobacteria survive within a granuloma created to localize and destroy infection

3
Q

In regards to host response evasion strategies, give an example of the “depress host response”

A

HIV destroys T cells; Malaria depresses immune response

4
Q

Viruses, spirochetes, and trypanosmones change surface antigens to avoid recognition by host. What is the name of this strategy?

A

antigenic change

5
Q

Viruses, bacteria, and protozoa produce acute infections faster than the immune response can develop. What is the name of this strategy?

A

rapid replication

6
Q

Genetic heterogeneity among hosts always provides some individuals with greater susceptibility or reduced immune status. This allows survival in what type of individuals?

A

weakly responsive individuals

7
Q

These are glycoproteins produced by many cells; especially leukocytes

A

interferons

8
Q

IFN-_ and IFN-_ both inhibit viral protein synthesis and activate leukocytes to kill viruses

A

IFN alpha; IFN beta

9
Q

IFN gamma signals for what?

A

upregulation of MHC I and II expression and antigen presentation; activates NK and Tc cells to kill virus-infected host cells

10
Q

Interferons are cell-specific in their production and effects, but virus non-specific. True or false?

A

True

11
Q

Interferons are induced by the presence of _-__

A

ds-RNA

12
Q

Once initiated, interferon continues for several ___

A

hours

13
Q

Interferon is produced in ___ and then ___, thus it doesn’t affect the producing cells

A

vesicles; excreted

14
Q

Interferon inhibits what?

A

translation of viral mRNA and viral replication

15
Q

Interferon production induces the common features of viral infection. What are these symptoms?

A

flu-like: fever, myalgia, headache

16
Q

Who discovered microorganisms using the microscope?

A

Van Leeuwenhoek (1674)

17
Q

Who used Linnaen method to organize bacteria: Genus species

A

Muller (1774)

18
Q

Who discovered anthrax, rabies, plague, cholera, and TB

A

Koch and Pasteur (1870’s)

19
Q

who created the first antibacterial, Salvarsan (for syphilis)?

A

Ehrlich (1910)

20
Q

Who discovered penicillin?

A

Fleming (1928)

21
Q

Who discovered sulfanilamide?

A

Domagk (1935)

22
Q

Who discovered streptomycin?

A

Waksman (1943)

23
Q

Who was the first to cultivate viruses using cell culture?

A

Enders (1946)

24
Q

What microbes can you visualize under a light microscope?

A

protozoa and bacteria (10^-6)

25
Q

What microbes can you visualize with an electron microscope?

A

viruses (10^-8)

26
Q

These are deviant and disruptive proteins. Associated with Mad Cow Disease

A

prions

27
Q

These are obligate intracellular parasites or lack cell well; cause cell and tissue destruction. Ex: chlamydia, mycoplasma, Rickettsia

A

degenerate bacteria

28
Q

These microbes are free-living, possess and cell wall. The prokaryotic type lacks a nuclear membrane, ER, and mitochondria

A

bacteria

29
Q

These microbes can be simple or complex. They are eukaryotic, contain an ER, mitochondria, and golgi; can be unicellular or multicellular; and utilize asexual reproduction

A

fungi

30
Q

These microbes are eukaryotic; complex, unicellular or multicellular.
Ex: cryptosporidium, tapeworm

A

parasites

31
Q

These microbes are ectoparasites

ex: mites, fleas, lice, sarcoptes scabiei

A

arthropods

32
Q

Spores, prions, and mycobacteria are examples of what type of organism?

A

resistant

33
Q

This type of sterilization utilizes boiling (killing vegetative cells) or the use of an autoclave (killing spores in 15 min or more)

A

moist heat

34
Q

This type of sterilization utilizes an over for 2-3 hours at 170 degrees celsius to effectively kill spores

A

dry heat

35
Q

This type of sterilization utilizes HEPA filters and removes microorganisms

A

filtration

36
Q

This type of sterilization utilizes germicidal UV, ionizing gamma, and produces DNA damage

A

radiation

37
Q

This type of sterilization utilizes toxic alkylating agent used for heat-sensitive materials, however, toxic or mutagenic by products

A

ethylene oxide gas

38
Q

In ____ there is total destruction of all microorganisms. In ____ there is destruction of most organisms. In ____ most organisms on skin or in tissue are killed.

A

sterilization; disinfection; antisepsis

39
Q

With disinfection, spores and mycobacteria might not be killed. True or false?

A

true

40
Q

Hot water, glutaraldehyde, peracetic acid, hydrogen peroxide, phenolics, alcohols, ammonium are all examples of what?

A

disinfectants

41
Q

Antisepsis kills most organisms including ____, but not ____

A

mycobacteria; spores

42
Q

In regards to antisepsis, this is a carrier of iodine, which precipitates/oxidizes proteins, kills most organisms, skin disinfection, residual antiseptic ability.

A

iodophors

43
Q

In regards to antisepsis, this is slower killing, but has residual action, utilizes chlorine (powerful oxidant)

A

chlorhexidine

44
Q

In regards to antisepsis, these compounds attack lipid membranes, kill mycobacteria, and their action is improved by halogens

A

phenolic compounds

45
Q

What is the phenol coefficient?

A

a ratio of dilution factors used to compare an agent against phenol under constant conditions

46
Q

Quarternary ammonioum compounds are 4 organic groups linked to nitrogen. What do they attack?

A

membranes

47
Q

___ is the mixing of chromosomal elements from different strains, the mechanism of genetic shift

A

reassortment

48
Q

___ is the mechanism of genetic drift (small changes)

A

mutation

49
Q

What does reassortment require?

A

segmented genomes

50
Q

What type of mechanism do RNA viruses: Bunyaviridae, Orthomyxoviridae, Arenaviridae, and Reoviridae utilize?

A

mechanism of “genetic shift” where influenza viruses rapidly acquire new hemagglutinin and neuraminidase. This is the initiating factor in many epigenetics.

51
Q

The following functions are of what type of cells?:
Bind DNA
DNA uptake
DNA integration

A

competent cells

52
Q

S. pneumoniae, S. aureus, and B. subtilis are all Gram ____

A

positive

53
Q

N. meningitidis, N. gonorrhoeae, H. flu, and E. coli are all Gram _____

A

negative

54
Q

Name the prokaryotic toxins (ABCDE)

A
shigA-like toxin (E. coli)
Botulinum toxin (Cl. botulinum)
Cholera toxin (V. cholerae)
Diphtheria toxin (C. dip)
Erythrogenic toxin (S. pyogenes)
55
Q

Sigella flexneria is an ____

A

adhesin

56
Q

Episomes, sexual pili, and homology dependent recombination are all aspects of part of prokaryote genetics?

A

conjugation

57
Q

True or false? There are many Gram Positive species and few Gram negative species that participate in conjugation.

A

false; many Gram neg, few Gram pos

58
Q

In regards to prokaryote genetics, this is the exchange between two chromosomes, all organisms (except most RNA viruses) utilize this. Follows: chromosomal transformation, transduction, or conjugation

A

recombination

59
Q

Recombination occurs in most ___ viruses and the ___ at the DNA provirus stage

A

DNA; Retroviridae

60
Q

Among RNA viruses, only the _____ show recombination

A

Picornaviridae

61
Q

This can be considered “illegitimate recombination”. It is the jumping of genes or transposons.

A

Transposition

62
Q

Two copies of expressed genes in one cell. A functional gene will cover a deficiency caused by a mutant gene.

A

complementation

ex: 2 strains of virus in one cell, a plasmid carrying an active gene in a cell carrying an inactive mutant gene

63
Q

Two viruses in one cell. Progeny viruses may combine attributes of both parental viruses.

A

Phenotypic mixing

ex: progeny may have nucleic acid from one virus in a nucleocapsid containing protein components from a second virus

64
Q

These tests can be used to identify antibiotic resistant bacteria

ex: Mueller-Hinton

A

diffusion tests

65
Q

These tests can determine the MIC (minimum inhibitory or bacterial concentration) useful for treatment options

A

Dilution tests

66
Q

Is the following a virus or bacteria?:
filterable agents
obligate intracellular parasites
depend on host

A

virus

67
Q

Viruses reproduce by ___

A

assembly

68
Q

Viral genomes can be single or double stranded chromosomes. True or false?

A

true

69
Q

Viral genomes are only unsegmented. True or false?

A

false; can be segmented or unsegmented

70
Q

Bacteria reproduce by ____ > ____

A

duplication > fission

71
Q

Bacteria genomes are only unsegmented. True or false?

A

true

72
Q

The viral capsid (and envelope) is a protein coat resistant to the environment. It is made up of capsomer subunits called ____ and ____ which make up the 20 faces of the isohedral or icosadeltahedral capsid

A

pentamers; hexamers

73
Q

Pentamers and hexamers are made of ____

A

protomers

74
Q

Helical and complex viruses contain only ___, no ___

A

protomers; capsomers

75
Q

These are glycoprotein projections through the envelope and are the viral attachment site

A

spikes

76
Q

In regards to the viral propagation in the human host, what are three places of entrance?

A

respiratory, GI, parenteral

77
Q
Give the correct order of the viral propagation cycle at the cellular level:
penetration
adsorption
replication of nucleic acid
uncoating
maturation and release
A
Adsorption
Penetration
Uncoating
Replication of nucleic acid
maturation and release
78
Q

This is a common/highly specific process for viral cell invasion. It requires interaction between unique viral surface proteins and highly specific host cell surface receptor sites.

A

adsorption

79
Q

For the following virus, give the viral attachment protein, target cell, and cell surface receptor if it has one:
adenovirus

A

vap: fiber protein

target cell: epithelial (muco)

80
Q

For the following virus, give the viral attachment protein, target cell, and cell surface receptor if it has one:
EBV

A

vap: gp350, gp220

Target cell: B

csr: C3d, CR2

81
Q

For the following virus, give the viral attachment protein, target cell, and cell surface receptor if it has one:
HIV

A

vap: gp120

target cell: helper T

csr: CD4

82
Q

For the following virus, give the viral attachment protein, target cell, and cell surface receptor if it has one:
Influenza A

A

vap: hemagglutinin gp

target cell: epithelial (respiratory)

csr: sialic acid

83
Q

For the following virus, give the viral attachment protein, target cell, and cell surface receptor if it has one:
measles

A

vap: heamgglutinin gp

target cell: epithelial respiratory

84
Q

For the following virus, give the viral attachment protein, target cell, and cell surface receptor if it has one:
Rabies

A

vap: G protein gp

target cell: neuron

csr: Ach receptor, NCAM

85
Q

For the following virus, give the viral attachment protein, target cell, and cell surface receptor if it has one:
Rhinovirus

A

vap: VP1-2-3 complex

target cell: epithelial respiratory

csr: ICAM-1

86
Q

For the following virus, give the viral attachment protein, target cell, and cell surface receptor if it has one:
Rotavirus

A

vap: VP7

target cell: epithelial (columnar)

87
Q

these viruses have membranes that fuse, releasing the nucleocapsid into the cell

A

enveloped viruses

88
Q

these viruses have nucleocapsids that bind to the membrane receptor sites, then either are digested through the membrane or are engulfed and enter as a vesicle

A

naked viruses

89
Q

Uncoating of the plasmid always occurs in the ___ of the host cell

A

cytoplasm

90
Q

Coincident with the end of uncoating is the ___ phase (time of viral replication)

A

eclipse

91
Q

DNA viruses replicate where?

A

in the nucleus (except poxviruses)

92
Q

symmetrical transcription of dsDNA > dsRNA > induces ___

A

interferon

93
Q

In late transcription, viral capsid proteins are made in ____ > ____

A

cytoplasm; nucleus

94
Q

All RNA viruses replicate in the ____

A

cytoplasm (except orthomyxoviruses and retroviruses)

95
Q

The RNA viral genome must encode what? It is absent in eukaryotic cells

A

RNA-dependent RNA poly

96
Q

In regards to viral propagation by RNA viruses, the ssRNA that is released by uncoating will act as what?

A

dsRNA > mRNA > interferon

97
Q

In regards to naked viruses, maturation consists of two main processes:

A
  1. assembly of capsid
  2. capsid association with nucleic acid

note: maturation occurs at site of nucleic acid replication

98
Q

RNA viruses are usually released rapidly after maturation. True or false?

A

true

99
Q

DNA viruses are usually not released rapidly. True or false?

A

true

note: accumulate large numbers at site of maturation forming inclusion bodies

100
Q

How is an elevated virus released?

A

nucleocapsid buds out with envelope, antigenic mosaic of viral and host proteins stud the envelope, tends to be slowly/continuously released by budding

101
Q

These viruses have 2 membranes, 1 around the nucleoid and are released by cell lysis

A

complex

102
Q

Normally when a virus enters a cell, it reproduces at a rapid are and produces large numbers of progeny virus. This is called the ___ cycle

A

lytic

103
Q

The basis for latency has been attributed to what?

A

lysogenization
lack of pathogenicity of virus
suppression of immune system

104
Q

A latent infection is usually activated by what?

A

systemic shock