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Micro > Micro Midterm 2 > Flashcards

Micro Midterm 2 Flashcards

1
Q

Is Neisseria gonorrhea gram negative or positive

A

Gram negative

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2
Q

What is the shape of neisseria gonorrhea

A

diplococci

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3
Q

Is neisseria gonorrhea cytochrome oxidase positive or negative

A

positive

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4
Q

What are 2 nonliving infectious agents?

A

Prions and bacteria

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5
Q

What are prions?

A
  • abnormally configured self-replicating protein templates
  • Prions are proteins that adopt beta pleated configuration, so they dont work well and start causing neurological disease
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6
Q

What are viruses?

A

Nucleic acid (DNA or RNA) genes packaged in protein coats which can subvert host cells to replicate virus particles.

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7
Q

What are the 2 types of prokaryotes?

A

archaea and bacteria

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8
Q

What are some examples of eukaryotes?

A

animals (including worms), plants, fungi, algae, and protozoa

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9
Q

What is the defining factor of eukaryotes?

A

nuclear membrane

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10
Q

What are the characteristics of eukaryotes?

A
  • nuclear membrane
  • Multiple chromosomes
  • Double stranded DNA
  • Subcellular organelles (e.g., chloroplasts, mitochondria)
  • Larger ribosomes 80S, bound to endoplasmic reticulum (rough ER)
  • Larger cells, 10-100 um
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11
Q

What do eukaryotes have that prokaryotes dont?

A

nuclear membranes and rough ER (and other subcellular organelles)

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12
Q

What are characteristics of prokaryotes?

A
  • no nuclear membrane (nucleoid)
  • Single circular DS DNA chromosome
  • No subcellular organelles
  • Smaller ribosomes (70S), free in cytoplasm
  • Smaller cell size (0.2-3 um diameter)
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13
Q

Which organisms have cell walls?

A

prokaryotes and plants

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14
Q

Which organisms have rigid cell walls?

A

most bacteria

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15
Q

Which organisms have flexible cell walls?

A

spirochaetes

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16
Q

What are cell walls?

A

osmotic barriers found in prokaryotes and plant cells

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17
Q

List of classification for bacteria of medical importance:

A
  • Cell wall
  • Filamentous vs simple unicellular
  • Obligate intracellular vs free-living
  • Aerobic vs anaerobic
  • Gram positive vs gram negative
  • shapes (rods vs cocci)
  • Glucose fermenters vs nonfermenters
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18
Q

Are most bacteria filamentous or simple, unicellular?

A

simple, unicellular

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19
Q

Are most bacteria obligate intracellular or free living?

A

free living

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20
Q

Which bacteria are obligate intracellular?

A

chlamydia, coxiella, ehrlichia, rickettsia

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21
Q

What is the definition of aerobic?

A

Tolerate significant concentrations of ambient oxygen, does not imply use of oxygen

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22
Q

What is the definition of anaerobic

A

Poisoned by significant concentrations of ambient oxygen

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23
Q

Who invented the gram stain?

A

Hans Christian Gram, a danish physician

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24
Q

Which violet do they use for the gram stain now?

A

crystal violet instead of gentian violet

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25
Q

What is the red counterstain?

A

safranine, used to stain the decolourized (gram-negative) organisms

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26
Q

Describe the gram-positive cell wall.

A

Simple thick layer of peptidoglycan outside of the cell membrane. Contains techoic acid
- Simple matrix of peptidoglycan with some polymers (esp. techoic acid), exterior to the cytoplasmic membrane

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27
Q

Describe gram negative cell wall

A

complex structure with inner and outer membranes, LPS, porin proteins and thin peptidoglycan layer
- thin layer of peptidoglycan anchored inside the outer membrane (a structure not found in Gram positive bacteria) by murein lipoprotein

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28
Q

Gram positive or gram negative: porin proteins

A

Gram negative

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29
Q

Gram positive or gram negative: techoic acid

A

gram positive

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30
Q

Gram positive or gram negative: LPS

A

gram negative

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31
Q

What does LPS stand for?

A

Lipopolysaccharide

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32
Q

What are the different shapes of bacteria?

A
  • Cocci (chains vs clusters)
  • Rods (bacilli) cylindrical
  • Short rods (coccobacilli)
  • Curved
  • Spiral
  • Branched (filamentous)
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33
Q

What is an example of cocci shaped bacteria?

A

staph

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34
Q

What is an example of rod shaped bacteria

A

Salmonella typhi

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35
Q

What is an example of short rods?

A

haemophilus ducreyi

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36
Q

What is an example of a curved road bacteria

A

Vibrio cholera

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37
Q

Vibrio Cholerae

A
  • Gram-negative curved rod with single flagellum (polar)
  • mainly water borne
  • non-invasive intestinal infection
  • Major virulence factor is secreted cholera toxin
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38
Q

Composition of cholera toxin

A

Central active subunit A surrounded by a pentameric receptor-binding subunit B. The subunit A is responsible for the toxic activity

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39
Q

Which bacteria cause Japanese rat fever?

A

spirillum minus

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40
Q

What is an example of spiral bacteria

A

Spirillum minus

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41
Q

What is fermentation?

A

The anaerobic metabolism of sugars

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42
Q

Which type of bacteria is fermentation used to type?

A

gram-negative

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43
Q

What is a group that is hard to identify and treat?

A

nonfermenters

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44
Q

Why are prokaryote cells so small?

A

Because they dont have guts

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45
Q

which cells have a higher surface area to volume ratio (X20)

A

prokaryotic cells

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46
Q

High surface to volume ratio = ?

A

greater metabolic activity

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47
Q

What are the 3 explanations as for why gonorrheae is referred to as the clap?

A
  • Le clapatier, area in France
  • Clapoire: means pus forming
  • Mother clap, in england (died from drive by fruiting)
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48
Q

What are capsules

A

Hydrophobic extracellular polysaccharides or protein polymers.
- They resist phagocytosis

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49
Q

Examples of slime layers:

A

biofilms
Glycocalyx
Plaque (on teeth)
Vegetations (on heart)

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50
Q

What are cytoplasmic membranes?

A
  • Very similar to that of eukaryotic cells: phospholipid bilayer
  • Metabolically active
  • Invaginations called mesosomes
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51
Q

gram negative or gram positive: high pressure (5 to 20 atm)

A

Gram positive

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52
Q

Gram negative or positive: Lower pressure (3 to 5 atm)

A

gram negative

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53
Q

What does peptidoglycan do?

A

Stiffener and osmotic shield

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54
Q

What is the composition of peptidoglycan?

A

Alternation subunits of monosaccharides N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM), cross linked at NAM by peptide chains

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55
Q

What are lipopolysaccharides?

A
  • AKA endotoxin
  • Found in gram negatives
    Three components: O antigen, core polysaccharide, lipid A
  • Lipid A puts the toxin in endotoxin
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56
Q

Why do people go into shock when they are infected with gram negative bacteria?

A
  • Because they have lipopolysaccharides which are endotoxins with 2 components ( O antigen, core polysaccharide, and lipid A)
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57
Q

Characteristics of mycobacteria cells walls:

A
  • Acid fast: resistant to decolorization by even acid
  • Similar to gram positives, but contains more lipids (60%, including a unique class of long chain Beta-hydroxylated fatty acids called mycolic acids
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58
Q

What do pili do?

A
  • AKA fimbriae
  • Mediate adhesion to other cells
  • Specialized sex pili mediate conjugation
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59
Q

What is transduction?

A

It is the spreading of a virus

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60
Q

What is flagella?>

A
  • Whiplike structures responsible for cell motility
  • Hollow tube and basal body, composed of flagellin
  • Require cell energy to move
  • Only motile bacteria have them
  • Carry H antigens
  • polar vs peritrichous
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61
Q

What is associated with H antigen?

A

flagella

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62
Q

What are spores?

A
  • Repackaged copies of bacterial DNA in highly impermeable, 6-layered envelope. Does not divide
  • 2 cell membranes with 2 layers of peptidoglycan in between, keratin coat, lipoprotein exosporium
  • Germinates to vegetative (dividing) bacteria after activation
  • Bacillus (aerobic) and Clostridium (anaerobic) only
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63
Q

Which bacteria form spores?

A

Bacillus (aerobic) and Clostridium (anaerobic)

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64
Q

What are aerobic gram positive cocci?

A

Staphylococci and streptococci

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65
Q

Which bacteria looks like grapes?

A

staphylococcus

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66
Q

Where can you find staphylococcus aureus?

A
  • In the anterior nares, skin and throat
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67
Q

What is special about staph aureus (specific test)

A

coagulase positive

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68
Q

Which is the nastiest staph (99%)

A

staph aureus

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69
Q

Which is the coagulase positive staph?

A

staph aureus

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70
Q

What are staph aureus virulence factors?

A

Cell wall virulence factors:
- Protein A: which binds to the Fc portion of IgG and inhivits phagocytosis
- Fibronectin-binding protein (FnBP)
Membrane damaging exotoxins:
- alpha, beta, gamma, omega, and leukocidin
Superantigens exotoxins:
- these protein toxins have an affinity for relatively highly conserved region of the T cell receptor, the MHC class II complex. They stimulate a massive T-cell response (app. 20%, contrasted with the usual 0.01%) with outpouring T cell cytokines TNF-alpha, IL-2, and interferon-gamma.
- Exfoliatin: causes expanded staph scalded skin syndrome
- Enterotoxins A, B, C, D, E, G which causes staph food poisoning
- Toxic shock syndrome toxin (TSST-1)

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71
Q

FnBP: fibronecting-binding protein (in staph aureus)

A

Fibronectin (body’s mucosal defence proteins) solubilizes in the fridge and precipitates out when it is heated (opposite from normal). It coats our mucosal lining, it likes to occupy the same places as gram-negative rods like to bind to. So by coating our mucosal linings with fibronectin, it competes with gram negatvie. So most of our nasal mucosa is gram positive. So staph aureus not only binds to our tissues but it binds to fibronectin

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72
Q

What so superantigen exotoxins do? (Staph Aureus)

A
  • these protein toxins have an affinity for relatively highly conserved region of the T cell receptor, the MHC class II complex. They stimulate a massive T-cell response (app. 20%, contrasted with the usual 0.01%) with outpouring T cell cytokines TNF-alpha, IL-2, and interferon-gamma.
  • Exfoliatin: causes expanded staph scalded skin syndrome
  • Enterotoxins A, B, C, D, E, G which causes staph food poisoning
  • Toxic shock syndrome toxin (TSST-1)
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73
Q

What are the 4 major diseases associated with Staph Aureus?

A
  1. Localized abscess: skin and soft tissue: I & D is mainstay of therapy. Bone (osteomyelitis)
  2. Sepsis and acute endocarditis
    3- Hospital acquired and post-influenzal pneumonia: when someone is sick, elastase is abundant and cleaves fibronectin and gram negative rods move in
  3. Toxin-associated syndromes
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74
Q

What is folliculits/furunculosis?

A

Folliculitis is localized abscesses. Infection of the hair follicles, when they are small they are folliculitis and if they grow bigger, they are furunculosis. Most dermatologic eruptions do not occur on thick skin because there are no hair follicles (Staph aureus)

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75
Q

What are the toxin associated syndromes involved with Staph aureus?

A
  1. Food poisoning
    - Enterotoxins A to E, and G
  2. Expanded Staphylococcal Scalded skin syndrome
    - Ritters disease: no antibodies nor kidney function
    - Classic scalded skin syndrome: proper kidney function but no antibodies
    - Staphylococcal scarlet fever: antibodies and kidney function
    - Bullous impetigo (blister)
  3. Toxic shock syndrome
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76
Q

Who discovered the toxic shock syndrome associated with staph aureus?

A

James K Todd

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77
Q

Which bacteria is he talking about when he says you have to remove a tampon?

A

Staph aureus

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78
Q

What can a tampon cause?

A

Toxic shock syndrome related to staph aureus.

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79
Q

What are the symptoms associated with Toxic Shock syndrome?

A
  • High fever
  • Hypotension
  • Diffuse erythema (resembling sunburn)
  • Hyperemia of mucous membranes (red: eyes, lips, labia)
  • Vomiting and diarrhea
  • Sometimes progresses to multi-system organ failure and death
  • Late superficial desquamation (peeling skin)
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80
Q

How to treat toxic shock syndrome?

A
  • Remove the source of intoxication (drain abscess, and remove tampon)
  • Agressive IV fluid replenishment
  • IV immunoglobulin
  • Antibiotics mainly serve to prevent recurrences
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81
Q

What does MRSA stand for?

A

methacylin resistant Staph Aureus

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82
Q

What does VISA stand for?

A

Vancomycin resistant staph aureus

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83
Q

What does CAMRSA stand for?

A

community acquired methacylin resistant staph aureus

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84
Q

What are the symtoms of CAMRSA?

A
  • large soft tissue abscesses which tend to relapse

- May cause sepsis

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85
Q

What is staphyloccus epidermidis characteristic for?

A

Produces slime and has affinity for prosthetic devices

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86
Q

Staphyloccus epidermis:

A
  • Coagulase negative
  • Skin commensal, opportunistic infections
  • produces slime, has affinity for prosthetic devices
  • Antibiotic resistant, need vancomycin
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87
Q

What is the second most common cause of UTIs in young women?

A

Staph saprophyticus

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88
Q

What is the most common cause of UTIs in young women?

A

E. coli

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89
Q

Staphylococcus saprophyticus:

A
  • Coagulase negative
  • Novobiocin resistant
  • 2nd most common cause of UTI in young women
  • Antibiotic susceptible
  • Grow on dead things
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90
Q

Which bacteria is notorious to grow on dead things?

A

staph saprophyticus

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91
Q

Are streptococci aerobic or anaerobic?

A

aerobic, but they do not utilize oxygen

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92
Q

Characteristics of Streptococci:

A
  • gram positive
  • spherical
  • aerobic (but do not use oxygen)
  • Usually stain in chains
  • complex nutritional requirements
  • Lack of catalase enzyme
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93
Q

How is strep distinguished from staph?

A

By colonial morphology (small, translucent colonies often hemolytic) and by lack of catalase enzyme

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94
Q

Classification of strep:

A
  • By hemolytic reaction (alpha, beta, alpha prime)
  • By Lancefield grouping (serotyping of C carbohydrate from cell wall: A, B, C…)
  • By phenotypic characteristics (biochemical tests)
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95
Q

What are the classification of Streptococcus pyogenes?

A
  • Beta-hemolytic
  • Lancefield group A
  • Penicillin susceptible
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96
Q

What is beta hemolytic, Lancefield group A, and penicillin susceptible?

A

Streptococcus pyogenes

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97
Q

What are the virulence factors of strep pyogenes?

A
  • Capsule: hyaluronic acid
  • Fimbriae: M protein
  • Protein F: fibronecting-binding protein
  • Exotoxins: pyrogenic exotoxins, streptokinase, streptodornases, hyaluronidase, streptolysins O and S, and C5a peptidase
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98
Q

What is associated with M protein

A

Fimbriae

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99
Q

What is protein F?

A

fibronectin binding protein

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100
Q

What are the streptococcus pyogenes diseases?

A
  • Acute suppurative infections (pus forming)
  • Toxin-mediated syndromes
  • Post-streptococcal disease (which is an unfortunate consequence of activation of our own immune systems)
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101
Q

What are the acute suppurative infections related to steptococcus pyogenes?

A

Pharyngitis:
- self-limited, buy potential for rheumatic fever
- Small % of pharyngitis
- Secondary to contact with a case or nasopharyngeal carrier
Skin and soft tissue infections:
- Impetigo: amber crusts
- Cellulitis: soft tissue infection, rapidly spreading
- Erysipelas: a superficial contained lymphangitis, features peau d’orange skin
- Necrotizing fascilitis, non gas forming (flesh eating disease)
Sepsis:
- puerperal sepsis, but primary sepsis is rising
- Splenectomized patients predisposed

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102
Q

What bacteria is associated with Peau d’orange?

A

strep pyogenes

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103
Q

What is the proper term for peau d’orange

A

erysipelas

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104
Q

Amongst the skin and soft tissue infections associared with strep pyogenes, which one is clearly demarcated with the eye and which one do you have to touch?

A

To the eye: erysipelas

To touch: cellulitis

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105
Q

What are the step. Pyogenes toxin-mediated syndromes?

A
  1. Scarlett fever
    - Pharyngitis with erythematous skin eruption, strawberry tongue, and Pastia’s lines due to pyrogenic exotoxin
  2. Streptococcal Toxic shock syndrome
    - Due to pyrogenic exotoxin acting as superantigen– massive T cell activation and cytokine release
    - shock and multiorgan failure
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106
Q

Which bacteria is most famously associated with Scarlett fever?

A

S. pyogenes, but there is a staph scarlet fever

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107
Q

Which bacteria is most famously associated with Toxic shock syndrome?

A

Staph aureus, but also a streptococcal toxic shock syndrome

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108
Q

What are the post-streptococcal diseases

A

1- Acute glomerulonephritis

  • 1-3 weeks after s. pyogenes infection at any body site
  • Small number of nephritogenic strains, defined by M protein, and T antigen
  • Hematuria, hypertension, edema
  • Excellent prognosis, but promp treatment is not preventative
    2. Rheumatic fever
  • 2-4 weeks after s. pyogenes pharyngitis only
  • prompt treatment is preventative
  • primarily due to host factors
  • Fever, migratory polyarthritis, carditis, and other signs.
    3. Erythema nodosum
  • multiple tender nodules on anterior lower extremities and face
  • many infections and drugs, not solely post-strep
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109
Q

S. pneumoniae

A
  • Lancet-shaped diplococci
  • alpha-hemolytic, no Lancefield antigen
  • Normal throat flora, carried by up to half the population, depending on season
  • About 20% of strains in Canada are resistant to penicillin
    Autolysin: present in cell wall, causes colonies to be dime-shaped
    Pneumolysin: present in cytosol, released by autolysin, and damages mammalian cell membranes
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110
Q

What are the s. pneumoniae diseases?

A
  1. Lower respiratory tract infections: community-acquired pneumonia (most common bacterial cause), acute exacerbations of chronic bronchitis
  2. Upper respiratory tract infections: the most common cause of pediatric otitis media and sinusitis, up to 50%
  3. Bacterial meningitis: one of most common causes
  4. Sepsis: splenectomized patients predisposed
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111
Q

Which strep is alpha-hemolytic, no lancefield antigen

A

S. pneumoniae and the virians group

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112
Q

Which strep is group B?

A

s. agalactiae

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113
Q

S. agalactiae

A
  • Group B
  • neonatal pneumonia, sepsis, and meningitis
  • Carried in the vagina by 25 % of normal women, also common in throats of both sexes
  • Infants can be colonized during birth, all serotypes
114
Q

Which strep is group C?

A

the ones associated with horses

115
Q

Which strep is associated with causing caries?

A

The viridians group

116
Q

What is the Viridians group?

A
  • alpha-hemolytic Streptococcus species which do not possess Lancefield antigens, not usually referring to s. pneumoniae
  • Normal oral flora
  • the most common cause of subacute bacterial endocarditis
  • S. mutans associates with caries
117
Q

What is the most common cause of subacute bacterial endocarditis?

A

The viridans group

118
Q

What does strep in the blood suggest?

A

endocarditis

119
Q

What are the 2 main classes of gram-negative rods?

A
  1. The enteric bacteria (enterobacteriaceae)

2. The nonfermenters

120
Q

What are the 4 cardinal characteristics of enterobacteriaceae?

A
  • Ferment glucose
  • Convert nitrates to nitrites
  • If they have flagella, they are peritichous
  • cytochrome oxidase positive
121
Q

Enterobacteriaceae

A
  • normal flora of the mouth, oropharynx, genitalia, distal urethra, and especially the large bowel
122
Q

What is the shared determinant of pathogeneicity in enterobacteriaceae?

A

LPS: lipopolysaccharides

123
Q

What are the components of LPS:

A

o antigen, core polysaccharide, and lipid A

124
Q

What is the most common cause of UTIs?

A

escherichia coli (e. coli)

125
Q

How is e. coli typed?

A

O antigen- LPS
H antigen- flagella
K antigen- capsule

126
Q

What is ETEC?

A

enterotoxigenic E. coli

127
Q

What is the major cause of traveler’s diarrhea?

A

ETEC: enterotoxigenic E. coli.

128
Q

What does enteroinvasive e.coli cause?

A

bloody diarrhea

129
Q

Which E. coli strain was found in Walkerton?

A

verotoxigenic or enterohemorrhagic e. coli (VTEC, EHEC)

130
Q

What does verotoxigenic and enterohemorrhagic e.coli cause?

A

bloody diarrhea, and hemolytic uremic syndrome

131
Q

For which e. coli strain are antibiotics contraindicated?

A

verotoxigenic (enterohemorrhagic) e. coli (VTECH, EHEC)

132
Q

Salmonella enterica ssp. enterica

A
  • Food (esp. poultry, eggs), water, pet turtles, African dwarf frogs
133
Q

What does salmonella enteria ssp. enterica cause?

A

diarrhea, extraintestinal disease, endocarditis

134
Q

Is salmonella enterica ssp. enterica: antibiotics contraindicated?

A

yes

135
Q

What causes typhus?

A

salmonella enterica ssp. enterica serovar. Typhi

136
Q

What do you get when you eat or drink something fertilized with human waste?

A

typhus, from salmonella enterica ssp. enterica serovar. typhi.
- antibiotics indicated

137
Q

What type of flagella does shigella species have?

A
  • none

- nonmotile

138
Q

Which bacteria causes dysentery with red jelly feces?

A

shigella species

139
Q

What is the species associated with cold cut contamination?

A

yersinia enterocolitica

140
Q

Which enterobacteriacea is related to pseudoappendicitis?

A

yersinia enterocolitica

141
Q

What caused the black death, the plague?

A

yersinia pestis

142
Q

What do the squirrels in SW USA carry?

A

yersinia pestis

143
Q

Which painting involves St-Sebastian praying to take the plague away?

A

Yersinia pestis

144
Q

which enterobacteriaes are nonmotile?

A

shigella and klebsiella pneumoniae

145
Q

Which enterobacteriae cause pneumonia in alcoholics?

A

Klebsiella pneumoniae

146
Q

What is special with serratia marcescens?

A

blood red pigment

147
Q

How are nonfermenters distinguished from enterobacteriaceae?

A
  • Failure to acidify the butt of Kllgler’s iron Agar (KIA) or Triple Sugar Iron Agar (TSI)
148
Q

What are the 2 nonfermenting species?

A
  • pseudomonas aerigunosa
  • Acinetobacter anitratus
  • Stenotrophomonas maltophilia
149
Q

Pseudomonas aeruginosa

A

Cytochrome oxidase positive

Look green on agar plates (pyocyanin production)
Smells like grapes

Contaminate sterile solutions  nosocomial
Pneumonia, UTI, wound infection, burn infections
Hot tub folliculitis

150
Q

Which species causes ecthyma gangrenosum?

A

pseudomonas aeruginosa

151
Q

What are the pseudomonas aeruginosa community acquired infections?

A
  • Malignant otitis externa (glue ear) in diabetics
  • Hot tub folliculitis
  • Endocarditis in IV drug abusers
  • Osteomyelitis of calcaneum after penetrating injury
152
Q

Which nonfermenter is most likely to contaminate a sterile solution and even disinfectants?

A

acinetobacter species

153
Q

Which specie caused CF camps to close?

A

Burkoldaria cepacia

154
Q

Which are the catalase negative gram positive rods?

A
  • Lactobacillus and ersipelothric rhusiopathiae
155
Q

which species are important to maintain the acidic environement of the vagina

A

lactobacillus

156
Q

Which specie is related to butchers hands and fish cleaners?

A

Erysopelothric rhusiopathiae

157
Q

What cause erysipeloid?

A

Erysopelothrix rhusiopathiae

158
Q

What are the catalase positive gram positive rods?

A
  • Bacillus
  • listeria monocytogenes
  • Corynebacterium
159
Q

What is the only aerobic spore former?

A

Bacillus

160
Q

What causes the fried rice syndrome?

A

bacillus cereus

161
Q

Describe the enterotoxins associated with bacillus cereus:

A

There are emetic and diarrheal enterotoxins. Emetic enterotoxin is heat stable

162
Q

What are the medusa head colonies?

A

bacillus anthracis

163
Q

What looks like ground glass type of hemolysis on blood Agar?

A

Listeria monocytogenes

164
Q

Which is the species that involves a toxin that brings the specie into the brain to cause meningitis?

A

Listeria monocytogenes

165
Q

How does listeria monocytogenes cause damage?

A

After phagocytosis by macrophages, a toxin called listeriolysin O damages the phagolysosome allowing the organisms to escape into the cytosol where they divide. They assemble actin filament tails which push the bacteria towards the cell surface and into pseudopods which contact other host cells.

166
Q

Which specie looks like chinese symbols?

A

Corynebacterium

167
Q

Which specie causes diptheria?

A

Corynebacterium

168
Q

What are the complications of diptheria?

A

1- local necrosis: pseudomembrane in the oropharynx which can asphyxiate
2- toxin can enter the general circulation and poison the heart

169
Q

What so anaerobes lack that makes them unable to survive in oxygen.

A

superoxide dismutase

170
Q

What are some clinical clues of anaerobic infection:

A
  • foul odour
  • Infection located in proximity to mucosal surface
  • Bite wounds
  • Gas in tissues or discharge
  • Mixed organisms seen on gram stain fail to grow in aerobic culture
171
Q

Which infections commonly involve anaerobes vs seldom do?

A

DO: brain abscess, deep neck space infection, dental abscess, lung abscess, aspiration pneumonia, bronchiectasis, intraabdominal infection, wound infection floowing surgery to GI or female genital tract, diabetic foot ulcers, gas gangrene, breast abscess (especially infra areolar), and perirectal abscess.
DONT: meningitis, acute sinusitis and otitis, pharyngitis, bronchitis, acute cholecystitis, spontaneous peritonitis, urinary tract infections, acute osteomyelitis

172
Q

What is mendelson’s syndrome?

A

aspiration pneumonia due to aspiration of vomit.

173
Q

What are the gram positive spore forming rods?

A

Clostridium

174
Q

What are the different types of Clostridiums?

A

c. tetani
c. botulinum
c. perfringens
c. difficile

175
Q

which toxin causes the spasms in tetanus

A

tetanospasmin

176
Q

What is the presenting symptom in tetanus?

A

trismus

177
Q

which specie looks like a tennis racquet?

A

clostridium tetani

178
Q

In which case does one case consist of an outbreak?

A

clostridium botulinum

179
Q

Which specie results from improper home canning and related to why kids cannot have honey?

A

clostridium botulinum

180
Q

Which specie is used for Botox?

A

clostridium botulinum

181
Q

which specie causes gas gangrene

A

clostridium perfringens

182
Q

Who have the highest rate of carriers of c. dif?

A

infants under 8 months of age and hospitalized patients

183
Q

What is the most common cause of infectious diarrhea in hospitals and long term care facilities?

A

C. difficile

184
Q

Bacteroides fragilis

A
  • bacteroides are the major anaerobes of the colon
  • gram negative rods
  • cause peritonitis and abdominal abscesses
  • Produces beta lactamase
185
Q

What is a gram negative diplococci?

A

neisseria gonorrhea

186
Q

What is a fastidious organism?

A

gonorrhea: needs special enriched media and CO2

187
Q

Is gonorrhea cytochrome oxidase positive or negative?

A

positive

188
Q

What are the virulence factors of neisseria gonorrhea?

A
  • Por A protein
  • Opa proteins (mediate adherence)
  • Rmp proteins
  • LOS (lipo-oligosaccharide)
  • pilin protein
189
Q

Which bacteria expresses LOS (lipo-olygosaccharide)

A

neisseria gonorrhea

190
Q

What are the infection syndromes associated with gonorrhea?

A

urethritis and cervicitis

  • Arthritis dermatitis syndrome
  • Monoarthritis
  • Prepubescent females: vaginitis
191
Q

what is associated with profuse purrulent discharge in males?

A

gonorrhea

192
Q

What are females with gonorrhea at risk for?

A

pelvic inflammatory disease

193
Q

What is Fitz-Hugh-Curtis syndrome?

A

It is the string adhesions under the liver (happens in females with gonorrhea when the infection spreads up from the uterus and into the fallopian tubes then out into the abdominal cavity)

194
Q

What are the complications of gonorrhea?

A
  • Disseminated infection
  • Fitz Hugh Curtis syndrome
  • Ophthalmia neonatorum
  • Pelvic inflammatory disease
195
Q

When would you treat gonorrhea?

A

When you know they have it, when you suspect they have it.

196
Q

How is neisseria meningiditis spread?

A

not sexually, but by close contact and respiratory.

197
Q

What is Waterhouse-Friedrichson syndrome?

A

Adrenal necrosis that occurs in patients with neisseria meningitidis

198
Q

Which subgroups of neisseria meningiditis are present in Canada vs the americas?

A

B, C, and Y are emergent in the americas and W in Canada

199
Q

What are the curved bacteria?

A

Vibrio, campylobacter and helicobacter

200
Q

Which bacteria corkscrews there way through fluids faster than any other bacteria?

A

campylobacter

201
Q

is campylobacter gram positive or negative

A

negative

202
Q

Which bacteria causes explosive diarrhea?

A

campylobacter

203
Q

Campylobacter

A
  • slender spiral gram negative
  • Single polar flagelum which allows them to corkscrew their way through fluids faster than any other bacteria
  • Microaerophilic (likes less oxygen) and capnophilic (likes more CO2)
  • Assacharolytic (doesnt break down sugars)
  • Requires special selective medium
204
Q

What is the bacteria in which wild birds form the principal reservoir for farm animals?

A

campylobacter

205
Q

Where is campylobacter found?

A

raw or undercooked poultry, meat, fish, and shellfish. Commonly in raw milk due to fecal contamination at milking and occasionally to campylobacter mastitis

206
Q

What is the most common cause of acute enteritis in developed countries?

A

campylobacter entiritis

207
Q

What are the 2 species of campylobacter?

A

c. jejuni and c. coli (jejuni causes 80 to 90% of infections)

208
Q

Which 2 bacterias can cause pseudoappendicitis?

A

yersinia entero. and campylobacter

209
Q

What is the bacteria that lives in Brackish waters?

A

vibrio vulnificus

210
Q

Vibrio:

A
  • motile
  • Oxidase positive
  • gram negative
  • Lives in brackish water
  • commonly associated with seafood
  • O and H antigens are present
211
Q

Vibrio cholera:

A
  • O1 strains cause cholera, non O-1 strains cause milder diarrhea
  • Contaminated drinking water
  • Cholera toxin binds to GM 1 gangliodise receptors on intestional mucosa, activates cyclic AMP which inhibits sodium absorption and causes secretion of chloride
  • Dehydration must be treated promptly
212
Q

What does the cholera toxin look lie?

A

central active (A) subunit surrounded by non-toxic pentameric binding (B) subunits.

213
Q

Who is considered to be the father of epidemology?

A

John Snow

214
Q

Who discovered Cholera?

A

John Snow

215
Q

Where was the cholera pump located?

A

Broadwick and Poland, in Soho England

216
Q

Which disease involves stool that is clear as water?

A

Cholera

217
Q

What is the vaccine available for cholera that also protects against travellers diarrhea?

A

Dukoral

218
Q

If someone is swimming in salt water with an open wound, what are they especially at risk for?

A

vibrio vulnificus

219
Q

What are preventative measures associated with vibrio?

A

avoid consumption of raw shellfish, particularly by patients with liver disease and avoid swimming in salt water with open wounds

220
Q

What makes helicobacter unusual?

A

They colonize the stomach.

221
Q

Helicobacter:

A

multiple polar flagella

  • colonize the stomach
  • Main species is H. pyloti which has similarities to the campylobacters
  • outstanding property is the production of a very potent urease which splits ammonia from urea to produce an alkaline environment in the stomach.
222
Q

What does helicobacter cause?

A
  • Acute gastritis
  • ulcers
  • Associated with gastric cancer and gastric B-cell lymphoma MALTomas
223
Q

How do you treat helicobacter?

A

triple therapy

224
Q

What are the 3 types of spirochaetes?

A

treponema, borrelia, and leptospira

225
Q

Are spirochaetes gram positive or negative?

A

Gram negative

226
Q

Spirochaetes:

A
  • Gram negative
  • Corkscrew rods with axial flagella and outer sheath
  • Flexible cell wall
227
Q

What is the bacteria related to syphilis?

A

treponema pallidum

228
Q

Treponema pallidum:

A
  • Syphilis, the Great pox, the Great imitator: T. pallidum ssp. pallidum
  • T. pallidum ssp. Endemicum: not sexually transmitted, it is a syphilis commonly seen in North Africa and Middle East called bejel or njovera
  • T. pallidum ssp. Pertenue: yaws, frambesia tropica.
229
Q

Which Treponema is related to raspberry-like outbreaks on the skin and yaws ?

A

T. pallidum ssp. Pertenue

230
Q

Which treponema is not sexually transmitted and seen in Northern African countries?

A

T. pallidum ssp. Endemicum

231
Q

Which disease is associated with Henry the 8th?

A

T pallidum ssp. pallidum: syphillis

232
Q

What is the most chronic infectious disease?

A

treponema pallidum: syphilis

233
Q

What is the 1/3 rule in infectious diseases/

A

1/3 self cure
1/3 progress to tertiary
1/3 keep relapsing

234
Q

What are the primary signs of syphilis?

A

chancres (at site of inoculation), they are painless and go away after 3 weeks

235
Q

What are the secondary signs of syphilis?

A

maculopapular eruption including palms and soles, condylomata lata (warts) (6 months)

236
Q

What are the tertiary signs of syphilis?

A

endarteritis obliterans- gummata (lesions)(years)(when arteries plug up and cause defiguring lesions)

  • Charcot’s joint
  • and shuffling gate
237
Q

What is the only treatment option for syphilis?

A

penicillin

238
Q

What is Jarisch-Herxheimer reaction?

A

It is an inflammatory reaction after treatment with penicillin that can be treated with advil.

239
Q

Who discovered Syphilis?

A

Sir William Osler

240
Q

What is the Argile Robinson pupil?

A

when it can accomodate but doesnt react.

241
Q

What is the bacteria that is associated with skin discolorations?

A

treponema carateum

242
Q

Treponema carateum:

A
  • pinta: acute and chronic nonvenereal skin infection
  • skin discoloration leads eventually to depigmentation
  • Found only in isolated rural populations living undercrowded, unhygienic conditions in the American tropics
243
Q

Borrelia

A
  • Highly motile spirochaetes, flagella beneath outer membrane, linear chromosome
  • LINEAR CHROMOSOME
  • maintained in nature by cycling through wild animals and ticks
244
Q

What are the two species associated with borrelia?

A
  • borrelia recurrentis (lice)

- borrelia duttonii (ticks)

245
Q

Which bacteria causes trench fever?

A

borrelia recurrentis

246
Q

Which bacteria is associated with lice?

A

borrelia recurrentis

247
Q

Borrelia recurrentis:

A
  • Louse-borne (epidemic) relapsing fever
  • Mainly in Africa, esp. Ethiopian higlands
  • Fever lasting 2 to 9 days alternating with afebrile periods of 2 to 4 days
  • Up to 10 relapses
  • Popular during the war: battle fatigue
248
Q

Which specie is associated with lyme disease?

A

borrelia burgdorferi

249
Q

What is the tick responsible for transmission of lyme disease?

A

Ixodes scapularis: the deer tick

250
Q

In which stage of lyme disease do joint syndromes occur?

A

2nd stage

251
Q

Lyme disease (3 stages)

A

1: Erythema migrans and flu-like symptoms
2: arthralgia, arthritis, meningitis, Bell’s palsy, painful radiculopathy, cardiac conduction defects, and myocarditis
3: chronic arthritis and progressive CNS disease

252
Q

What is erythema migrans?

A

the circle like skin eruptions around a tick bite

253
Q

What is the bacteria related to raccoon hunting?

A

leptospira

254
Q

What is leptospirosis?

A
  • Primary lesion is disruption of cell membranes of endothelial cells of small blood vessels throughout the body
  • Due to glycolipoprotein toxin
  • Widespread capillary leakage and petechial haemorrhage
  • Worse in lungs, omentum, and pericardium.
255
Q

What are the phases of leptospirosis?

A

1: 1-2 weeks: fever and malaise, decreases or disappears after 1 week.
2: aseptic meningitis, hepatitis, nephritis, conjunctivitis, IgM titre increases

256
Q

Which one of the spiral bacteria are not true spirochaetes?

A

spirillum minus

257
Q

Which bacteria is associated with rat bites?

A

spirillum minus

258
Q

Spirillum minus:

A
  • rigid cell wall
  • The common form of sporadic rat-bite fever in Asia, particularly Japan
  • Spirillary fever, Sodoku
  • Distinctive reddish purple skin plaques
  • Previously healed bite wound reactivates when symptoms appear ***
259
Q

What is an example of an obligate intracellular bacteria?

A

Chlamydia

260
Q

What is an example of energy parasites?

A

Chlamydia

261
Q

Chlamydia:

A
  • small obligate intracellular bacteria
  • Unable to synthesize ATP: energy parasites: used their host’s ATP
  • Structurally similar to small gram negative bacteria except no peptidoglycan
  • unique reproductive cycle
262
Q

What is the unique reproductive cycle of Chlamydia?

A
  • Intracellular form is the reticulate body
  • RB divides repeatedly by binary fission 48h until a large cytoplasmic inclusion is formed
  • RB’s condense to form elementary bodies which are released into the environment by lysis of the host cell
  • EB’s are phagocytosed by different susceptible host cells
  • EB prevents fusion to phagosome and lysosome
  • The EB reorganizes into the larger RB

EB: elementary bodies
RB: reticulate bodies

263
Q

What are the chlamydia species?’

A
  • Chlamydia trachomatis
  • Chlamydia psittaci
  • Chlamydophila pneumoniae
264
Q

Chlamydia trachomatis:

A
  • Inclusion bodies stain with iodine
  • 2 groups of serovars that cause different syndromes:
    • A to L - trachoma biovar. ( D to K) commonly cause genital tract infections in North America and Europe
    • L1, L2, L2a, L3 – lymphogranuloma venereum biovar
265
Q

What is the leading cause of blindness in developing countries

A

trachoma

266
Q

What is trachoma?

A

Chronic infection of chlamydia trochamatis leads to scarring and trichiasis. It is the leading cause of blindness in developing countries.
Serovars: A, B, Ba, and C

267
Q

What are non-gonococcal urethritis/cervicitis?

A
  • Serotypes D - - K
  • Most common cause of NGU, especially in college students
  • Females are often asymptomatic by at risk for PID which leads to infertility and chronic pelvic pain
  • neonates born to infected mothers at risk for inclusion conjunctivitis, occasionally infant pneumonia
268
Q

What is lymphogranuloma venereum?

A
  • symptom of chlamydia
  • Serovars L1, L2, L2a, and L#
  • uncommon in north america and europe
  • transient papules on external genitalia followed in 1-2 months with painful inguinal and perirectal lymphadenopathy
  • Groove sign
269
Q

What is groove sign associated with ?

A

lymphogranuloma venereum (chlamydia trachomatis)

270
Q

What causes chlamydia psittaci?

A
  • transmitted by inhalation of dust contaminated with feces or respiratory secretions of infected birds (history)
  • Pneumonia often associated with headache and splenomegaly
    Parrot-like birds
271
Q

Chlamydophila pneumoniae

A
  • CA pneumonia, brinchitis, sinusitis
  • Person to person transmission
  • common, but seldom diagnosed due to poor availability of reagents
  • tantalizing associations of high antibody titres with coronary atherosclerosis and asthma trials
272
Q

What is the smallest free living organism>

A

mycoplasma

273
Q

Mycoplasma:

A
  • smallest free living organism
  • trilaminar outer membrane, stains well with Giemsa but not with Gram
  • no cell walls: resistant to cell wall attacking antibiotics (beta-lactams)
  • Cell membrane contains sterols, which must be in growth medium
  • Slow growing
274
Q

What are the characteristics of mycoplasma?

A
  • Ubiquitous: found everywhere
  • Frequently contaminate tissue cultures
  • Pass through filters designed to trap bacteria
  • related to the clostridia
275
Q

Disease associations

A

pneumonia: M. pneumoniae
Non gonecoccal urithritis (NGU): M. genitalium
Postpartum fever: M. hominis and U. urealyticum
Arthristis in immunosuppressed and hypogammaglobulinemic: M. hominis and u. urealyticum
Misc. in immunosuppressed: M. hominis

276
Q

What is the second most common cause of community acquired pneumonia

A

Mycoplasma pneumoniae

277
Q

What is the leading cause of community acquired pneumonia

A

Strep pneumoniae

278
Q

Which pneumonia causing bacteria is related to summer outbreaks every 3 to 4 years?

A

M. Pneumoniae

279
Q

What are the clinical features of M. pneumoniae?

A

Chest x-ray looks worse than you would expect

  • anorexia, nausea, vomiting, diarrhea
  • musculoskeletal: myalgia, diarrhea
  • Erythema multiforme
  • transient hemolytic anemia
  • Meningoencephalitis (70% of hospitalized)
  • Relapses, persistent cough
280
Q

What is the second most common cause of NGU after chlamydia trachomatis?

A

M. genitalium

281
Q

Which bacteria is associated with AIDS

A

mycoplasmas: fermentans, penetrans, and pirum

282
Q

Ureaplasma urealyticum

A
  • genital commensal; sexual transmission
  • Very small colonies; splits urea
  • Established roles in postpartum fever and arthritis in immunosupressed and hypogammaglobulinemic patients
  • Moderate evidence for causality: NGU, infection stones, pneumonia

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