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Term 4 > Microbiology > Flashcards

Microbiology Flashcards

1
Q

Cell wall: proks, euks, virus

A

Proks: all except mycoplasma
Euks: only fungi and algae
Virus: no

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2
Q

Cytoplasmic membrane: proks, euks, virus

A

Proks: no sterols (except mycoplasma)
Euks: sterols
Virus: none (some with lipid coat)

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3
Q

DNA/RNA: proks, euks, virus

A

Proks: SS DNA, single, no proteins
Euks: >1 chromosome, proteins
Virus: SS, DS, DNA/RNA, some enzymes

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4
Q

Ribosomes: proks, euks, virus

A

Proks: yes
Euks: yes
Virus: no

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5
Q

Respiration: proks, euks, virus

A

Proks: cell membrane
Euks: mitochondria
Virus: none

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6
Q

Reproduction: proks, euks, virus

A

Proks: asexual (binary fission)
Euks: sexual + asexual
Virus: asexual

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7
Q

What prokaryote requires a living host?

A

Ricketsia

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8
Q

What prokaryote doesn’t have a cell wall, but contains sterols?

A

Mycoplasma

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9
Q

Which eukaryotes have cell walls?

A

Fungi + Algae

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10
Q

What are 3 factors that influence pathogenesis?

A
  1. Tissue tropism
  2. Host immune response
  3. Secondary replication sites (virus)
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11
Q

What are innate defenses of: eye, resp, GIT, skin, UG?

A

Eye: blinking, tears, lysozyme
Resp: mucus, cilia, phags, lysozyme, cough/sneeze
GIT: pH, flora, peristalsis, GALT
Skin: lactic acid, proprionic acid, lysozyme, flora
UG: urine, acidity/lavage, lysozyme, vag acid, flora

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12
Q

Differentiate between endogenous and exogenous microbes.

A

Endogenous: in/on the body (skin microbes: cut–>deeper)
Exogenous: encounters with microbes in the environment (ingress-on epi surface vs. penetration-within fluid/tissue)

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13
Q

Differentiate between ingress and penetration w/ respect to exogenous microbes

A

Ingress: ex/ inhalation, ingestion (surface of epithelium)
Penetration: ex/wound, insect bite (deep to epidermis – within tissue or fluid)
Sexual can be both

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14
Q

Differentiate between infection and intoxication.

A

Infection: microbe completes all steps of pathogenesis and multiplies
Intoxication: damage caused by toxin; NO multiplication of microbe

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15
Q

Which bacteria do not have a cell wall?

A

Mycoplasma

Ureaplasma

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16
Q

Which bacteria have a flexible cell wall?

A

Borrelia
Leptospira
Treponema

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17
Q

Which bacteria have a filamentous, rigid cell wall?

A

Actinomyces
Mycobacterium
Nocardia

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18
Q

Which bacteria have a simple cell wall, but are obligate intracellular?

A

Chlamydia/Chlamydophilia
Rickettsia
Ehrlichia

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19
Q

Which are the gram-positive bacteria?

A

Cocci: staphylo, strepto, entero
Bacilli: bacillus, clostridum, cornybact, lactobacilli, listeria, propionibact

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20
Q

Which are the gram-negative bacteria?

A

Cocci: moraxella
Non-enteric bacilli: bartonella, bordetella, brucella, burkholderia, francisella, haemophilis, legionella, pseudomonas
Enteric bacilli: campylobacter, enterobacter, eschericia, helicobacter, klebsiella, proteus, salmonella, shigella, vibrio, yersinia

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21
Q

Define and give examples of the following coccus terms:

Single
Pair
Chain
Cluster
Tetrad
A 
Single: no example
Pair: streptococcus pneumonia
Chain: streptococcus pyogenes
Clusters: all staphylo
Tetrad: sarcinia
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22
Q

List all 4 gram-staining steps

A
  1. Crystal violet
  2. Gram’s iodine
  3. Decolorizer (organic solvent)
  4. Safranin
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23
Q

For which bacteria is it appropriate to do an acid-fast stain?

A

Gram’s resistant bacteria

  • Mycobacterium
  • Nocardia
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24
Q

What color are acid-fast bacteria vs. non acid-fast bacteria?

A

Acid-fast: red/pink

Non-acid-fast: blue/green

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25
Q

What are the major internal, cell envelope, and external structures of a prokaryote?

A

Internal: cytosol, nucleoid, ribosomes
Cell envelope: glycocalyx, cell wall, cell membrane
External: flagella, pili, fimbrae, endospores

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26
Q

What do bacterial chromosomes have that serve a function like histones?

A

Mg2+ ions

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27
Q

Are bacterial chromosomes DS, SS, circular, linear, 1 or 2 chromosomes? Are there any exceptions

A

SS, circular, 1 chromosome
Linear: streptomyces, borrelia
2 chromosomes: rhodobacter sphaeroides

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28
Q

What am I describing: >=1 virulence genes, large genomic area, located next to tRNA, associated with transposons, unstable

A

Pathogenicity islands

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29
Q

What is a plasmid? Describe 4 key features.

A

Extra-chromosomal, circular, self-replicating DNA

  • Abx resistance (R plasmid)
  • Tolerance to metals
  • Production toxins
  • Mating capabilities (F plasmid)
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30
Q

R plasmid

F plasmid

A

R: abx resistance
F: mating

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31
Q

What percentage of cell membrane is phospholipid vs. protein?

A

Phospholipid: 20-40%
Protein: 60%

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32
Q

What is the function of the periplasmic space?

A

Nutrient transport, nutrient axquisition, detox (beta-lactamases), membrane derived oligosaccharides, osmoprotectants

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33
Q

What is the mesosome?

A

Present in mostly gram+ bacteria; extensive invagination associated with the nucleoid/cell replication

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34
Q

Describe bacterial ribosomes

A

70s, 50s-23s, 5s, 30s-16s
60% RNA
40% protein

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35
Q

What are endoflagella?

A

Axial filaments in spirochetes bacteria that are anchored at the end of a cell causing rotation and movement of the cell (in periplasmic space)

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36
Q

What connects NAM-NAG?

A

Beta-1,4 glycosidic linkages

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37
Q

What is the Schwartzman reaction?

A

Dermal necrosis caused by lipotechoic acid in gram + bacteria

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38
Q

Gram positive bacteria cell wall contains

A

Lipoteichoic acid, teichoic acid

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39
Q

Gram negative bacteria cell wall contains

A

LPS, LP (Lipid A anchored to cell membrane)

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40
Q

Gram-negative bacteria have endotoxin/exotoxin?

A

Endotoxin

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41
Q

Acid-fast bacteria do no gram-stain because they have…

A

Waxy mycolic acids that resists gram stain (arabinogalactan esterification)

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42
Q

Lysozyme

A

Breaks beta-1,4 linkages between NAM-NAG

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43
Q

Spheroplast/Protoplast

Gram + / Gram -

A

Protoplast: gram positive – entire cell wall is destroyed
Spheroplast: gram negative – only part of cell wall is destroyed

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44
Q

Penicillin…

A

Binds to penicillin-binding proteins (PBP) transpeptidases that inhibits the formation of NEW cross-linkages in the cell wall

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45
Q

K, M, V antigen

A

K: capsule
M: streptococcus pyogenes
V: salmonella

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46
Q

Describe some functions of the glycocalyx

A

Adherence to surfaces, antigenic activity, anti-phagocytic, prevention neutrophil killing bacteria, prevention PMN leukocyte migration, toxicity, protection

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47
Q

What is the Quellung reaction?

A

Swelling reaction– determines capsule presence by microscopy

  • Anti-serum+bacteria–> swelling
  • Typing!
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48
Q

Do cocci have flagella?

A

No

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49
Q

Are flagella essential for survival?

A

No

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50
Q

Is hemorrhagic necrosis more likely with gram positive or negative bacteria?

A

Negative

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51
Q

What are the various polar/lateral arrangements of flagellum?

A

Polar: monotrichous, amphi (bi-polar), lopho
Lateral: petri

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52
Q

Differentiate between basal bodies of gram positive and gram negative bacteria.

A

2 rings - gram + (S+M)

4 rings - gram - (S+M+L+P)

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53
Q

What are the 3 components of flagella?

A
  1. helical filament
  2. hook
  3. basal body
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54
Q

What is H antigen?

A

Helical filament antigen (H-german word for hot condensation on a cold window)

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55
Q

Differentiate between positive and negative chemotaxis.

A

Positive: up [ ] gradient
Negative: down [ ] gradient

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56
Q

Who has a pilus: gram+ or gram-. What is a pilus? What is it composed of?

A

Gram- only

*Entry of genetic material during conjugation; composed of the protein: pilin

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57
Q

What is the role of fimbrae?

A

Attachment and adhesion to eukaryotic cells, predominately gram-

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58
Q

They glycocalyx has this layer, which can often adhere to surfaces, i.e. plastics. What bacteria often colonize?

A

Slime layer, i.e. Staphylococus epidermidis

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59
Q

What 2 bacteria produce endospores?

A

Bacillus, clostridium

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60
Q

T/F Endospores are highly resistant.

A

True!

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61
Q

Where does one find calcium-diplcolonic acid?

A

Within the endospore core

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62
Q

What makes endospores so resistant?

A

Coat: keratine-like, impermeable
Cortex: PG, few X-links
Spore wall: PG; cell wall germinating
Core: genetic material, energy, protein synthesis, calcium-dipicolinic acid

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63
Q

Differentiate between CCW/CW bacterial/flagella movement.

A

CCW: smooth swimming
CW: tumbling (turning)

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64
Q

Differentiate between sporulation and germination

A

Sporulation: unfavorable growth conditions
Germination: favorable growth conditions

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65
Q

In bacteria, who codes for virulence factors?

A

Plasmid

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66
Q

Mycoplasma are resistant to:

A
  1. Lysozyme
  2. Penicillin
  3. Cycloserine
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67
Q

How does mycoplasma reproduce?

A

Cytoplasmic replication lags behind DNA replication

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68
Q

Who is the smallest organism capable of reproduction?

A

Mycoplasma

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69
Q

How does mycoplasma grow on media? Is there an exception?

A

Grows diphasic colonies

* Except M. pneumoniae

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70
Q

What is special about mycoplasma’s attachement organelles?

A
  1. Tapered tip
  2. P1 adhesin
    * Surface epithelial cells
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71
Q

T/F Rickettsiaecease are cultivated on agar.

A

F: obligate intracellular pathogens

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72
Q

T/F Rickettsiaecease are zoonotic (arthropod vector)

A

True

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73
Q

What do rickettsiaecase have in their cell walls?

A

Diaminopimelic acid

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74
Q

Differentiate between the elementary body and the reticulate body of chlamydiaceae.

A

EB: infectious, non-replicative, adapted for EC survival, metabolically inactive
RB: non-infectious, replicative, IC survival, met active

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75
Q

T/F All obligate intracellular bacteria are zoonotic.

A

True

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76
Q

Define the following terms:
Symbiont
Commensal
Parasite

A

S: both benefit
C: one benefits
P: one benefits, one harmed

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77
Q

Mould vs. Yeast: uni/multicellular, hyphae, a/sexual reproduction

A

Mould: multicellular, hyphae, a/sexual reproduction (spores)

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78
Q

Differentiate between septate and aseptate fungi

A

Septate: separated, multinuclei
Aseptate: non-separated, multinuclei

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79
Q

What is a mycelium? What does it consist of?

A

Intertwined mat of hyphae

2 portions: vegetative and reproductive (spores)

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80
Q

What are dimorphic fungi?

A

Same organism exhibits 2 different forms – mould and yeast

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81
Q

Are fungi more likely to be yeast or mould at physiological temperature?

A

Yeast

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82
Q

Which fungi exist solely as yeast and solely as mycelial?

A

Yeast: torula
Mycelial: Aspergillus

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83
Q

Fungi appear gram + or -

A

+

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84
Q

What does fungal staining tell us?

A
  1. Yeast vs. mould
  2. Hyphae (septate/non-septate)
  3. Spores (thallospores or sporangium)
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85
Q

Which fungus has a capsule?

A

Cryptococcus neoformans

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86
Q

T/F You can use the India ink stain for fungi

A

True

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87
Q

What is a fungal cell wall made of?

A

Chitin

* N-acetyl-D-glucosamine

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88
Q

T/F Fungal cell walls have beta-1,4 glycosidic linkages

A

True

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89
Q

T/F Fungal cell membranes contain this type of sterol

A

Ergosterol

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90
Q

Fungi are haploid/diploid

A

Haploid

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91
Q

T/F Fungi have toxins

A

True

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92
Q

Bacterial cell replication is called…

A

Binary fission

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93
Q

T/F Bacterial growth is constant

A

True, exponential

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94
Q

How do yeast replicate?

A

Budding (asexual)

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95
Q

How do moulds replicate?

A

Sex + Asex

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96
Q

Define: psychrophilic, psychotroph (fac psychrophile), mesophile, thermophile

A

Psychro: 20
Meso: 20-40
Thermo: >45

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97
Q

Define optimal temperatures for different types of fungi.

A

Mold: sub-physio (dimorphic)
Yeast: physio

98
Q

What two enzymes are necessary to remove harmful ROS?

A
  1. SOD (O2- + H+ –> H2O2 + O2)

2. Catalase (H2O2–> H2O + O2)

99
Q

Determine the presence of SOD & catalase for obligate aerobes, microaerophiles, obligate anerobes, fac anareobes

A

OA+FAn: SOD+Catalase
Micro: SOD
Obligate an: none

100
Q

Mold/yeast – O2 requirements

A

Mold: aerobes
Yeast: fac anaerobes

101
Q

Absorption and solution factors inc/dec Aw

A

Dec

102
Q

What is a halophile

A

Salt-tolerant bacteria – low Aw

103
Q

What is the Aw of sea water?

A

0.98

104
Q

Xerotolerant microbes can survive below this Aw…

A

0.6

105
Q

Differentiate between lithotrophs and organotrophs.

A

Litho: inorganic H/electron source
Organo: organic

106
Q

Most pathogens are: auto/hetero-troph, photo/chemo-troph, litho/organo-troph

A

Hetero, chemo, organo

107
Q

Differentiate between known/unknown laboratory media

A

Known: 100% known
Unknown: < 100% known

108
Q

Define these 4 types of media: all purpose, enriched, reduced, transport, selective, differential

A

Enriched: basal support + nurtient supplement (blood agar)
Reduced: addition of reducing agent to remove oxygen
Transport: preserve in transit
Selective: allows 1 species to grow and suppresses others (C-energy, pH, O2)
Differential: More than 1 grow, but visible change in agar

109
Q

How do you culture and plate fungi?

A
  1. Primary – selective isolation / sabouraud’s agar, with abx to prevent bacteria
  2. Secondary – culture & ID – incubate at 25C
110
Q

Define biocides.

A

Physical (temp) or chemical (disinfectant, antiseptic, antibiotic) agents to control growth of microorganisms.

111
Q

Is sterilization an all or none phenomenon?

A

Yes

112
Q

Differentiate between “-static” & “-cidal”

A
  • static: stop growth

- cidal: kill

113
Q

Order from sensitive to resistant: prion, large non-enveloped virus, small non-enveloped virus, enveloped virus

A

Sensitive—–> Resistant

Enveloped virus, large non-enveloped, small non-enveloped, prions

114
Q

What are the factors influencing choice of antimicrobial and outcome of treatment?

A
  1. Number and type of organism
  2. Presence of organic material (pus)
  3. Type of microbe/type of material/surface
115
Q

What is preferred for sterilization: moist or dry heat?

A

Dry

116
Q

Differentiate between anti-septic and anti-biotic

A

Anti-septic: on living surface

Anti-biotic: anti-microbe

117
Q

What is an autoclave?

A

Dry heat (121 celsius) under pressure (2 atm)

118
Q

Why might you choose to use ethylene oxide rather than an autoclave?

A

Heat sensitive material (i.e. plastic, suture, bone graft, heart valve)

119
Q

What is ethylene oxide?

A

Physical control of microbial growth

*Strong alkylator, cause mispairing of bases (reacts with guanine of DNA/protein) and halts metabolism

120
Q

What is the most difficult microorganism to kill?

A

Bacterial spores

121
Q

What is a key characteristic of antiseptics?

A

No toxicity of human tissue

122
Q

Order the following disinfectants from high risk to low risk: gluteraldehyde, peracetic acid, etoh, iodophor, surfactant

A 
Gluteraldehyde -- cross-linking
Peracetic acid -- oxidizing agent
ETOH -- Protein denaturation and coagulation
Iodophor -- oxidizing agent
Surfactant -- surfactant
123
Q

Among the following, which have the greatest effects as anti-septics? ETOH, clorhexidine, iodine, triclosan

A

ETOH = iodine&raquo_space; clorhexidine > triclosan

124
Q

What is the difference between narrow and broad spectrum antibiotics? Give an example of each.

A

Narrow: limited number of species (Flagyl – anerobes)
Broad: many species (aminoglycosides – gram+ and gram-)

125
Q

What is the ideal feature of an antibiotic?

A

Targets something unique to the infecting microorganism and not toxic to the host

126
Q

What are key considerations to take into account when using an anti-microbial agent?

A

Immune status of patient, degree of penetration (CSF, bone), combo therapy (potential for resistance), local environment (pH, O2), sensitivity of organism

127
Q

What are the 4 major classes of antibiotics & examples of each class?

A
  1. Cell wall-Penicillin (beta-lactam), cephalosporin, glycopeptides (vanc), carbapenem, cycloserine
  2. DNA/RNA- DNA- clofazimine, metronidazole, quinoline; RNA- Rifampin, rifabutin
  3. Protein- 30s (aminoglycosides, tetracyclin)/50s
  4. Metabolism - sulfonamide, trimethoprim, Para-aminosalicylic acid
128
Q

What are the 4 major mechanisms of antibiotic resistance?

A
  1. Permeability barriers – i.e. gram -
  2. Efflux pump
  3. Antibiotic target modification – i.e. MRSA
  4. Inactivating enzymes – i.e beta-lactamase
129
Q

How can you overcome beta-lactamase?

A

Use combination therapy of a beta-lactam and a beta-lactamase inhibitor (i.e. clavulanic acid)

130
Q

What is clavulanic acid?

A

Beta-lactamase inhibitor

131
Q

What are the 4 major genetic mechanisms for the acquisition and transfer of antibiotic resistance genes?

A
  1. Plasmid: conjugation
  2. Loose DNA: transformation
  3. Bacteriophage: transduction
  4. Transposon: transposition
132
Q

How would you define recombination (with respect to bacterial antibiotic resistance?)

A

Stable maintenance, incorporation into the chromosome (breaking and joining DNAD into new combinations)

133
Q

Differentiate between homologous and non-homologous recombination.

A

Homologous: conjugation, transformation, transduction

Non-homologous: transposition (cut and paste)

134
Q

What is high frequency recombination?

A

Complete transfer of F plasmid and its integration into the chromosome

135
Q

When would a bacterial cell acquire free floating DNA in the environment? What is this called?

A

Cell death; transformation

136
Q

What is special about DNA binding proteins in bacterial recombination?

A

Transformation; will discriminate which species DNA to accept

137
Q

Give 3 examples of bacteria that undergo transformation.

A
  1. Haemophilus
  2. Streptococci
  3. Neisseria
138
Q

What are the two major types of bacterial transduction?

A
  1. Lytic/virulent/generalized

2. Temperate/Specialized (lysogeny – bact carrying a prophage)

139
Q

What is Lysogeny?

A

When bacteria are carrying a prophage

140
Q

What are the limits on the use of each of the following drugs: aminoglycocide, glycoprotein, nitroimidazole, penicillin, cephalosporin

A 
NOT effective against:
Amino: anaerobes
Glycoproteins: gram negative
Nitroimidazole: aerobes
Penicillin: mycoplasma
Cephalosporin: mycobacteria
141
Q

Describe the mode of action of the bacterial protein synthesis inhibitors.

A

30s: amino/misreading DNA; tetracycline-block
50s: macrolide (transpeptidation and translocation), lincosamide (block binding at A/P sites), streptogramins (inhibit peptide bond formation)

142
Q

Aminoglycocides vs. Tetracycline

A

Amino: cidal – misreading bases
Tetra: static – block tRNA binding

143
Q

Describe the various generations of the penicillins.

A

1st: natty, Pen G
2nd: methicillin (penicillinase-resistant)
3rd: aminopenicillin - ampicillin (resist low pH)
4th: extended spectrum (gram +/-); peperacillin

144
Q

What are the 4 categories of antifungals?

A
  1. Direct membrane damage (polyenes, i.e. Ampho B)
  2. Nucleic acid syn (flucytosine)
  3. Cell membrane/ergosterol (azoles, allylamines)
  4. Cell wall/ beta-d-glucan + chitin (echinocandins, nukkomycin)
145
Q

For which fungal infections is echinocandins indicated?

A

Candida and Aspergillus, not C. neoformans

146
Q

Describe where the following bacteria tend to colonize:

S. mutans, S. salivarius, Campylobacter, N. gonorrhoae, B. pertussis, S. aureus

A 
S. mutans - enamel
S. salivarius - tongue epi
Campylobacter - intestinal mucosa
N. gonorrhoeae - uretheral epithelium
B. pertussis - upper RTI
S. aureus - nasal mucosa
147
Q

Fimbriae are characteristic of gram + or -

A

Negative

148
Q

Give an example of afimbrial adhesin that is a virulence factor.

A

B. pertussis ligand – filamentous hemagglutinin (FHA)

Prevention: FHA vaccine

149
Q

Is invasion necessary for all bacteria? Why

A

No; toxins (i.e. diptheria)

150
Q

What are the 6 steps of bacterial pathogenesis?

A
  1. Exposure/Entry
  2. Attachment
  3. Invasion
  4. Evasion immune response
  5. Effects on host
  6. Dissemination/shedding
151
Q

How can bacteria and fungi make their way into non-phagocytic cells? Give 2 examples.

A

Use of invasins/host cell cytoskeletal re-arrangement (i.e. membrane shuffling)

  1. L. monocyotgenes (internalin A)
  2. Shigella
152
Q

What are the 3 possible consequences of bacterial invasion?

A
  1. Restricted to the site of entry
  2. Spread to immediate underlying tissue, no further dissemination
  3. Spread to other body sites (dissemination)
153
Q

What are 3 bacterial dissemination enzymes?

A
  1. Hyaluronase
  2. Streptokinase
  3. Collagenase
154
Q

How do bacteria evade complement, phagocytosis, antibodies?

A

Complement: capsule, binding proteins, proteases, host cell mimicry
Phag: capsules, intracellular parasitism
Ab: MHC presentation/Ag-variation, Ig-inactivation

155
Q

What is one example of bacterial host cell mimicry?

A

Use of a hyaluronic acid capsule

156
Q

Is cryptococcus neoformans encapsulated?

A

Yes

157
Q

How does the body overcome encapsulated bacteria that need to be phagocytosed?

A

Opsonization – IgG, C3b

158
Q

How can bacteria evade complement and phagocytosis without the use of capsules?

A 
Elastase (Pseudomonas aeruginosa) -- inactivate C3b, C5a
C5a peptidase (S. pyogenes) -- inhibit phagocyte chemotaxis, degrade C5a
159
Q

How can bacteria evade macrophages and leukocytes?

A

Leukocidins – ADP-ribsolyaltion of protein controlling phosphatidylinositol (disruption of cellular activities)

160
Q

What are the 4 possible outcomes of infection on the host?

A
  1. Infection/Damage
  2. Permanent relationship
  3. Subclinical
  4. Prevention/clearance
161
Q

Differentiate between endo and exotoxins

A

Endo: high does, systemic, LPS, no toxioid, fever, cell lysis

162
Q

Differentiate between AB & A5B stucture.

A

AB: covalent, single gene single peptide, post-translationally modified to A/B fragments, diptheria
A5B: non-covalent, two genes encode for A/B subunits, cholera

163
Q

Zinc metalloendoprotease

A

Proteolytic cleavage of toxin; 2 linked fragments

  • LC (enzymatically active), HC (binding/translocation)
  • — Tetanus, Botox
164
Q

ADP-ribosylator toxins

A

Diptheria, cholera

165
Q

What are the 3 major components of a virus?

A
  1. Core with nucleic acid/protein
  2. Capsid
  3. Envelope
166
Q

What is the viral capsid? What are the 2 major capsid shapes?

A

Protection, nucleocapsid = protein shell

  • Proteins aggregate into capsomers
    1. Helical
    2. Icosahedral
167
Q

What is the viral envelope?

A

Surrounds nucleocapsid
“Shrink wrapped”
2 lipid bilayers interspersed with proteins
* Material from host and virus

168
Q

What are the 3 major types of viral proteins?

A
  1. Nucleo-proteins: replication
  2. Matrix proteins: links envelope and capside
  3. Surface proteins: glycoproteins
169
Q

The H. influenza virus has these 2 surface glycoproteins.

A

Hemagglutinin: attaches to sialic acid
Neuraminidase: aids in viral release

170
Q

How are viruses classified?

A

NA, symmetry, envelope, size

171
Q

What is a bacteriophage? Majority are ss/ds RNA/DNA?

A

DS DNA

* Virus of bacteria

172
Q

What are the 3 major mechanisms of viral detection?

A
  1. Biochemical (enzymes, PCR)
  2. Serological (ELISA, etc.)
  3. Electron microscopy
173
Q

The plaque assay for viral detection detects active/inactive/all virus?

A

Active

174
Q

What is a defective virus?

A

Complete virus particle, unable to replicate without helper virus

175
Q

What is a pseudovirus?

A

Non-viral DNA; infectious, cannot replicate

176
Q

What is a viriod? What is an example?

A

infectious, sub-viral, small circular SS RNA genome, i.e. Hep D (within Hep B)

177
Q

The name for a complete infectious viral particle

A

Virion

178
Q

Differentiate between structural and non-structural viral proteins.

A

Structural: packaged in mature virus

Non-structural: not packaged

179
Q

Every virus must be able to produce _____________ which can be recognized by cellular ribosomoes.

A

mRNA

180
Q

What are the 5 steps of the viral life cycle?

A
  1. Attachment (adsorption)
  2. Penetration (injection)
  3. Protein/Nucleic acid synthesis
  4. Assembly/packaging
  5. Virion release
181
Q

What are the 3 major phases of the viral life cycle (not the 5 actual steps)

A

Eclipse - undetectable
Maturation
Latent - progeny accumulates in cell; ends when free virus is released

182
Q

How do most viruses gain entry into a host?

A

Respiratory mucosa

183
Q

Are helical viruses enveloped?

A

Yes

184
Q

What are the 3 major things that determine the severity of a viral infection?

A
  1. Nature virus
  2. Site of infection
  3. Immune status of patient
185
Q

Differentiate between macule, papule, nodule, vesicular.

A

Macule: flat, colored
Papule: slightly raised
Nodule: larger raised
Vesicular: blisters

186
Q

What is epidermodysplasia verruciformis?

A

Rare inherited disorder that predisposes patients to widespread HPV & cutaneous sq. cell ca (think: tree man)

187
Q

What is an example of an oral/respiratory tract viral infection?

A

Influenza

188
Q

What is an example of a GIT viral infection?

A

Rotavirus

189
Q

What is an example of viral induced skin disease?

A

HPV

190
Q

HHV-5, aka ________ causes chorioretinitis in newborns.

A

CMV

191
Q

EBV is HHV__

A

HHV-4

192
Q

EBV is associated with these 3 cancers.

A
  1. Nasopharyngeal
  2. Burkitt’s lymphoma
  3. Hodgkin’s lymphoma
193
Q

HHV-8

A

Kaposi’s sarcoma

194
Q

HHV-4

HHV-8

A

4: EBV
8: KS

195
Q

Merkel cell polyomavirus is associated with…

A

Merkel cell carcinoma, a highly aggressive neuroendocrine carcinoma of the skin with high propensity of recurrence and mets

196
Q

HBV, HCV; DNA, RNA

A

HBV: DNA
HCV: RNA

197
Q

What are the possible outcomes following HCV infection?

A

Recovery, Rapid cirrhosis, Chronic infection

198
Q

HTLV-1 is associated with…

A

Adult T cell lymphocytic leukemia + spastic paraparesis myelopathy

199
Q

The 3 viruses that may increase one’s risk of developing non-Hodgkin’s lymphoma.

A
  1. HCV
  2. EBV
  3. HTLV-1
200
Q

JCV virus is associated with

A

glioma

201
Q

Describe the transformative capacity of the HPV virus

A

E6, E7 targets p53 & Rb; hence leading to hyper-proliferation

202
Q

Who are the facultative intracellular bacteria?

A

Some nasty bugs may live facultatively

Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Legionella, Yersinia

203
Q

What is the quellung reaction?

A

If bacteria are encapsulated, capsules will swell when specific anticapsular antisera are added

204
Q

What is special about M protein of S. pyogenes?

A

Can mimic heart tissue, so that when the immune system makes anti-protein M-Ab, it can target the normal heart tissue *rheumatic fever

205
Q

For what 3 conditions can a single positive antibody be allowed for a confirmatory diagnosis?

A

Lyme, HIV, Hep

206
Q

In an uninfected baby, IgM is present/absent and IgG rises/falls?

A

IgM absent

IgG falls every month

207
Q

In an infected baby, IgM is present/absent and IgG rises/falls?

A

IgM present

IgG rises

208
Q

Why would you draw a convalescent sample at 3-6 weeks?

A

To look for a 4-fold or greater increase in Ab response of IgG

209
Q

What is special about haemophilus, anerobes in regular bottles and N. gonorrhea in joint fluid?

A

Require prompt culture

210
Q

Differentiate between community-acquired diarrhea and inpatient diarrhea

A 
Community = parasite, viral, shigella, salmonella, campylobacter
Inpatient = C. diff
211
Q

What is an example of an ESBL?

A

Klebsiella pnuemonia, E. coli

212
Q

What is KPC?

A

Klebsielle pneumonia carbipenimase

213
Q

What are 2 examples of highly resistant bacterial organisms?

A

Beta-lactamases, carbipenemiase

214
Q

Most nosocomial infections become apparent after this time period

A

72 hours (3 days)

215
Q

Environmental microbe cultures vary over time, but the nosocomial infection rate remains the same. What is the conclusion?

A

its the people and human practice!

216
Q

What are the 4 major nosocomial infections?

A

UTI (catherter), pneumonia (VAP), SSI (hands, poor prophy), BSI (IV cath)

217
Q

Droplets are greater than

A

5 microns in size

218
Q

Who are the 4 major nosocomial microorganisms?

A
  1. MRSA (Methicillin resistant s. aureus)
  2. VRE (vanc. resistant enterococcus)
  3. C. diff (intestinal)
  4. Highly resistant negative rods (ESBL-enterobact, KPC-klebsiella, Acinetobacter-Iraq, Pseudomonas aeruginosa)
219
Q

How is staph aureus spread?

A

By hand to an open wound

220
Q

How can you reduce surgical site infections?

A

Pre-op prophy abx for qualifying surgery (dirty)

221
Q

How have US hospitals attempted to lower MRSA?

A

**Universal pre-admission screening/weekly screening; Screen all high risk people upon admission (nare swab/culture/PCR); if +, place in isolation

222
Q

Overuse of this antibiotic for the treatment of C. diff has led to the emergence of ______________ resistant organisms. The alternative is to treat with _____________________.

A

Vancomycin (C. diff)

** Metronidazole

223
Q

E. faecium is resistant to: (2 antibiotics)

A

Ampicillin, vancomycin

224
Q

C. diff produces 2 toxins.

A

A: enterotoxin
B: cytotoxin

225
Q

C. diff can cause this severe complication with 30-80% mortality

A

Pseudomembranous colitis

226
Q

Which kills spores: ETOH or soap/H2O

A

soap/H2O

227
Q

Mandatory cleaning of rooms on enteric precautions with this product has helped lower infection rates.

A

Clorox

228
Q

What are the 3 non-specific defenses of the upper-respiratory tract (not cilia).

A
  1. sIgA
  2. lactoferrin
  3. lysozyme
229
Q

What lasts long in the air: small droplets or dried droplets?

A

Dried

230
Q

Differentiate between the upper and lower respiratory tracts.

A

Upper: nose –> bronchioles; ciliated pseduostrat, mucus, sec IgA, swallow + lysozyme (33-35 degrees); NORMAL flora
Lower: sterile, non-ciliated, IgG, IgA, alveolar macrophages (37 degrees)

231
Q

Describe the interplay between professional and secondary pathogens.

A

Epithelial damage, airway function altered, upregulation/exposure of receptors

232
Q

Differentiate between antigenic drift & shift of the influenza virus.

A

Drift: gradual, loss of neutralizing Ab to H protein
Shift: rapid, usually result of co-infection

233
Q

Amantadine + Rimantadine

A

Influenza A only; M2 protein

234
Q

Zanamivir + Oseltamvir (Tamiflu)

A

Influenza A+B; N only

- virus binds to its own sialic acid

235
Q

What does not work in the treatment of the flu?

A
  1. Post-exposure treatment

2. Excessive antimicrobials — drug-resistance

236
Q

Differentiate between severity, animal reservoir, pandemic, epidemic, genetic changes for Influenza A, B, C

A

A: +++++ severe, animal reservoir, pandemic, S+D
B: yes epidemic
C: no epidemic

237
Q

Measles and mumps are transmitted…

A

Respiratory

238
Q

Antibodies are generated against H or N in influenza

A

H

239
Q

Differentiate between teleomorphs and anamorphs.

A

Teleomorphs: can sexually reproduce
Anamorphs: asexual reproduction

240
Q

Ajellomyces is teleomorph/anamorph?

A

Teleomorph (Histoplasma, blastomyces)

241
Q

Differentiate between H. capsulatum capsulatum/duboisii

A

Capsulatum: pulmonary/disseminated (E. US/LA), thin/small
Dubois: skin/bone lesions, thicker walled, larger

242
Q 
Describe the following opportunistic fungal pathogens:
Chemotherapy
M. ventilation
Malnutrition
AIDS
Neutropenic
A 
Chemotherapy: Aspergillus, PCP
M. ventilation: Aspergillus
Malnutrition: CN, PCP
AIDS: CN, PCP
Neutropenic: Aspergillus

Term 4 (3 decks)

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