L9 Otitis, sinusitis, diptheria, pertussis Flashcards

1
Q

causes of otitis externa

A

pseudomonas aeruginosa

staphylococcus aureus

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2
Q

causes of otitis media/sinusitis

A

streptococcus pneumoniae (50%)
moraxella catarrhalis
haemophilus influenzae

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3
Q

cause of diphtheria

A

corynebacterium diptheriae

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4
Q

cause of whooping cough/pertussis

A

bordetella pertussis

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5
Q

signs/symptoms of otitis externa

A

otalgia
otorrhea
fever

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6
Q

predisposing factors to otitis externa

A

moisture, insertion of foreign objects, trauma, chronic skin diseases

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7
Q

pseudomonas aeruginosa

A

G-
encapsulated
pigment producer

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8
Q

pseudomonas aeruginosa produces pigments

A

pyocyanin: non-fluorescent blue
pyoverdin: fluorescent green

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9
Q

pyocyanin

A

produced by many pseudomonas stains

generates reactive oxygen species

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10
Q

pyoverdin

A

produced by all pseudomonas strains

sequesters iron

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11
Q

something that sequesters iron

A

a siderophore

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12
Q

staphylococcus aureus

A

G+
Cocci in clusters
Coagulase positive
B hemolytic

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13
Q

bulging tympanic membrane due to pus in middle ear

A

acute otitis media

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14
Q

streptococcus pneumoniae

A
G+
lancet shaped diplococci
virulent strains are encapsulated
alpha-hemolytic
sensitive to optochin
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15
Q

beta hemolytic

A

staphylococcus aureus

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16
Q

alpha hemolytic

A

streptococcus pneumoniae

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17
Q

pseudomonas cause

A

otitis externa

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18
Q

staph aureus causes

A

otitis externa

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19
Q

strep pneumo causes

A

otitis media/sinusitis

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20
Q

moraxella catarrhalis causes

A

otitis media/sinusitis

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21
Q

haemophilus influenzae causes

A

otitis media/sinusitis

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22
Q

haemophilus influenzae

A

G-
coccobacilli
some nontypeable strains

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23
Q

moraxella catarrhalis

A

G-
diplococci
oxidase positive
Beta lactamase producer

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24
Q

resistant to beta lactams due to beta lactamase

A

moraxella catarrhalis

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25
Q

the only diplococci

A

moraxella catarrhalis

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26
Q

who gets a typmanocentesis to culture/gram stain

A

restricted pt populations

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27
Q

2 diseases that are diphtheria

A

cutaneous

diptheria/respiratory

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28
Q

corynebacterium diptheriae

A

G+
pleomorphic bacilli with palisade shape
metachromatic (volutin) granules
grow aerobically on blood agar

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29
Q

palisades

A

diptheriae have a V appearance

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30
Q

diptheria toxin is a

A

phage encoded A-B exotoxin

31
Q

diptheria toxin binds to

A

heparin-binding EGF receptor

32
Q

The A subunit of diptheria toxin, once acidified and released within the vesicle and moving to the cytoplasm

A

inactivates EF-2 via ADP ribosylation, halting protein synthesis

33
Q

chronic nonhealing sores or ulcers

A

cutaneous diphtheria due to nontoxigenic strain

34
Q

bull neck

A

severe respiratory diphtheria

35
Q

pseudomembrane

A

respiratory diphtheria

36
Q

respiratory diphtheria colonizes

A

pharynx

37
Q

ssudden onset of malaise, exudative pharyngitis, low grade fever, LAD

A

respiratory diphtheria

38
Q

pseudomembranes are composed of

A

fibrin
bacteria
WBCs
necrotic eptihelial cells

39
Q

systemic toxicity of respiratory diphtheria

A

myocarditis

demyelination

40
Q

diphtheria spread

A

asymptomatic carriers
person-to-person via respiratory droplets or skin contact
developing countries

41
Q

what can you culture diphtheria on

A

loeffler’s medium

cystein-tellurite agar

42
Q

loeffler’s medium

A

enhances formation of volutin granules in diptheria

43
Q

cystein-tellurite agar

A

diptheria grows a distinctive black color due to tellurite reduction, isolates are tested for toxin production

44
Q

volutin staining of diptheria

A

metachromatic (volutin) granules

45
Q

Tests for toxin production in diphtheria

A

Elek test
PCR
ELISA
Immunochromatographic strip assay

46
Q

Elek test for diptheria toxin production

A

immunodiffusion assay to secretion of exotoxin

47
Q

PCR test for diptheria toxin production

A

detect tox gene

48
Q

ELISA test diptheria toxin production

A

detects the exotoxin

49
Q

Immunochromatographic strip assay test for diptheria toxin production

A

detects the exotoxin and is very sensitive

50
Q

Bordetella pertussis

A
G-
small coccobacilli
grows aerobically on enriched agar
virulence factors adhesions, exotoxins
endotoxin
51
Q

4 pertuiss exotoxins

A

Pertussis toxin
Dermonecrotic toxin
Tracheal cytotoxin
Adenylate cyclase toxin

52
Q

Pertussis toxin

A

A-B exotoxin that inactivate Giz, causing increased cAMP and respiratory secretions.
inhibits phagocytic killing and monocyte migration
causes lymphocytosis

53
Q

Dermonecrotic toxin

A

pertussis: vasoconstriction causes ischemic necrosis

54
Q

Filamentous hemagglutin

A

pertussis: facilitates attachment, highly immunogenic

55
Q

Tracheal cytotoxin

A

Pertussis:
kills cilated epithelia cells
stimulates IL-1 release

56
Q

cause of lymphocytosis in pertussis

A

pertussis toxin

57
Q

pertussis effects

A

compromises small airways

58
Q

pertussis predisposes patients to

A

cough
atelectasis
cyanosis
pneumonia

59
Q

catarrhal stage of pertussis

A

inflammation of mucous membranes, nonspecific URI, 1-2 weeks

60
Q

when are patients with pertussis highly contagious

A

catarrhal stage

61
Q

paroxysmal stage of pertussis

A

attacks/spasms, up to 50/day
coughing followed by vomiting, “whoop”
lasts for weeks

62
Q

during the paroxysmal stage of pertussis

A

GI complications can occur due to vomiting and increased pressure

63
Q

serious complications of pertussis

A

pneumonia
encephalopathy
seizures
death

64
Q

pertussis occurs in

A

humans only

65
Q

how to presumptively diagnose pertussis

A

Serology: ELISA detects Igs to pertussis toxins or adhesions

4x increase

66
Q

how to definitively diagnose pertussis

A

culture sample on enriched medium

PCR

67
Q

enriched mediums for pertussis

A

Bordet Gengou agar

Regan Lowe agar

68
Q

pertussis labs

A

lymphocytosis

69
Q

Adenylate cyclase toxin

A

pertussis: similar to pertussis toxin, decreases chemotoxis

70
Q

encapsulated

A
staph aureus
pseudomonas 
strep pneumo (virulent strains)
71
Q

optochin sensitive

A

strep pneumo

72
Q

coagulase positive

A

s aureus

73
Q

oxidase

A

morexella

74
Q

lancet shaped

A

strep pneumo