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

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

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

2

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

mycobacteria survive within a granuloma created to localize and destroy infection

3

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

HIV destroys T cells; Malaria depresses immune response

4

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

antigenic change

5

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

rapid replication

6

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

weakly responsive individuals

7

These are glycoproteins produced by many cells; especially leukocytes

interferons

8

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

IFN alpha; IFN beta

9

IFN gamma signals for what?

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

10

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

True

11

Interferons are induced by the presence of _-__

ds-RNA

12

Once initiated, interferon continues for several ___

hours

13

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

vesicles; excreted

14

Interferon inhibits what?

translation of viral mRNA and viral replication

15

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

flu-like: fever, myalgia, headache

16

Who discovered microorganisms using the microscope?

Van Leeuwenhoek (1674)

17

Who used Linnaen method to organize bacteria: Genus species

Muller (1774)

18

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

Koch and Pasteur (1870's)

19

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

Ehrlich (1910)

20

Who discovered penicillin?

Fleming (1928)

21

Who discovered sulfanilamide?

Domagk (1935)

22

Who discovered streptomycin?

Waksman (1943)

23

Who was the first to cultivate viruses using cell culture?

Enders (1946)

24

What microbes can you visualize under a light microscope?

protozoa and bacteria (10^-6)

25

What microbes can you visualize with an electron microscope?

viruses (10^-8)

26

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

prions

27

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

degenerate bacteria

28

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

bacteria

29

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

fungi

30

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

parasites

31

These microbes are ectoparasites
ex: mites, fleas, lice, sarcoptes scabiei

arthropods

32

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

resistant

33

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

moist heat

34

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

dry heat

35

This type of sterilization utilizes HEPA filters and removes microorganisms

filtration

36

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

radiation

37

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

ethylene oxide gas

38

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.

sterilization; disinfection; antisepsis

39

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

true

40

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

disinfectants

41

Antisepsis kills most organisms including ____, but not ____

mycobacteria; spores

42

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

iodophors

43

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

chlorhexidine

44

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

phenolic compounds

45

What is the phenol coefficient?

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

46

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

membranes

47

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

reassortment

48

___ is the mechanism of genetic drift (small changes)

mutation

49

What does reassortment require?

segmented genomes

50

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

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

51

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

competent cells

52

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

positive

53

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

negative

54

Name the prokaryotic toxins (ABCDE)

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

55

Sigella flexneria is an ____

adhesin

56

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

conjugation

57

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

false; many Gram neg, few Gram pos

58

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

recombination

59

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

DNA; Retroviridae

60

Among RNA viruses, only the _____ show recombination

Picornaviridae

61

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

Transposition

62

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

complementation

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

63

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

Phenotypic mixing

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

64

These tests can be used to identify antibiotic resistant bacteria

ex: Mueller-Hinton

diffusion tests

65

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

Dilution tests

66

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

virus

67

Viruses reproduce by ___

assembly

68

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

true

69

Viral genomes are only unsegmented. True or false?

false; can be segmented or unsegmented

70

Bacteria reproduce by ____ > ____

duplication > fission

71

Bacteria genomes are only unsegmented. True or false?

true

72

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

pentamers; hexamers

73

Pentamers and hexamers are made of ____

protomers

74

Helical and complex viruses contain only ___, no ___

protomers; capsomers

75

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

spikes

76

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

respiratory, GI, parenteral

77

Give the correct order of the viral propagation cycle at the cellular level:
penetration
adsorption
replication of nucleic acid
uncoating
maturation and release

Adsorption
Penetration
Uncoating
Replication of nucleic acid
maturation and release

78

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.

adsorption

79

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

vap: fiber protein

target cell: epithelial (muco)

80

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

vap: gp350, gp220

Target cell: B

csr: C3d, CR2

81

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

vap: gp120

target cell: helper T

csr: CD4

82

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

vap: hemagglutinin gp

target cell: epithelial (respiratory)

csr: sialic acid

83

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

vap: heamgglutinin gp

target cell: epithelial respiratory

84

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

vap: G protein gp

target cell: neuron

csr: Ach receptor, NCAM

85

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

vap: VP1-2-3 complex

target cell: epithelial respiratory

csr: ICAM-1

86

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

vap: VP7

target cell: epithelial (columnar)

87

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

enveloped viruses

88

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

naked viruses

89

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

cytoplasm

90

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

eclipse

91

DNA viruses replicate where?

in the nucleus (except poxviruses)

92

symmetrical transcription of dsDNA > dsRNA > induces ___

interferon

93

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

cytoplasm; nucleus

94

All RNA viruses replicate in the ____

cytoplasm (except orthomyxoviruses and retroviruses)

95

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

RNA-dependent RNA poly

96

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

dsRNA > mRNA > interferon

97

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

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

note: maturation occurs at site of nucleic acid replication

98

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

true

99

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

true

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

100

How is an elevated virus released?

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

101

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

complex

102

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

lytic

103

The basis for latency has been attributed to what?

lysogenization
lack of pathogenicity of virus
suppression of immune system

104

A latent infection is usually activated by what?

systemic shock