Otitis/Dipth/Pertuss (lec 9)

Question 1

Otitis Externa is?

Predisposing factor?

Characteristics?

Answer 1

Inflamm of external auditory canal

moisture (swimmer’s)

otalgia, otorrhea
fever = systemic involvement

Question 2

OE caused by?

Answer 2

P. aeruginosa (-)

S. aureus (+)

Question 3

Pseudomonas aeruginosa microbe characteristics?

Answer 3

G- bacilli
Encapsulated
Pigment producer: Pyocyanin, Pyoverdin

Question 4

Staphylococcus aureus microbe characteristics?

Answer 4

G+ cocci
Encap
Coagulase +
β-hemolytic

Question 5

OE dx?

Tx?

Answer 5

exam, gram stain

Debride
Topical: Acidifyings, cortico
Oral abx if fever

Question 6

Acute Otitis Media vs Sinusitis

Answer 6

OM = inflam middle ear, (U) w/ fluid
Sin = inflam paranasal sinus

Question 7

AOM/Sinu caused by?

Answer 7

ºS. pneumo
H. influ
M. catarrhalis

Question 8

Streptococcus pneumoniae microbe characteristics?

Answer 8

G+ lancet diplo
Encap
⍺-hemolysis
Optochin sensitive

Question 9

Haemophilus influenza microbe characteristics?

Answer 9

G- coccobacilli

Non-typeable

Question 10

Moraxella catarrhalis microbe characteristics?

Answer 10

G- dipol
Oxidase positive
β-lactamase producer

Question 11

AOM Dx?

Tx?

Answer 11

Clinical
Cx, gram

Amoxicillin

Question 12

Sinusitis Dx?

Tx?

Answer 12

Clinical
Bx/CT

irrigation
decong
steroids
surg

Question 13

Cutaneous Diphtheria caused by?

Presents?

Answer 13

(U) non-toxic agent

non-healing ulcers

Question 14

Respiratory Diptheria:

Colonizes?

Sxs?

Answer 14

pharyngeal

Sudden onset:
exudative pharyngitis
mild fever
malaise
LAD
pseudomembrane over nostril (fibrin/bact/WBC)
"Bull neck"

Question 15

Diptheria carriers?

Transmission?

Answer 15

asym people

p-to-p via skin/resp droplets

Question 16

Diptheria agent?

Answer 16

Corynebacterium

G+ bacilli “chinese letters”
Metachromatic/Volutin granules

Question 17

Diptheria toxin?

Action?

Answer 17

A-B exotoxin
Stim’d by low [Fe]

Binds heparin-bind recep ->
endocytosed -> releases A

A stops protein synth (local necrosis/edema)

Produces more toxin -> system toxicity

Question 18

Diptheria Dx?

Tx?

Answer 18

Clinical
Cx: Loeffler, Cysteine-tell
Stain
Toxin tests: Elek, PCR, ELISA, Immu

Question 19

Diptheria tx?

Answer 19

Antitoxin
Erythromycin
Quarantine

Vaccine

Question 20

Pertussis (Whooping Cough) caused by?

Answer 20

Bordetella pertussis

Question 21

Bordetella pertussis microbe characteristics?

Answer 21

G- coccobacilli

Endo/Exo/Adhesion toxins

Question 22

Pertussis dz stages?

Answer 22

1) Catarrhal: inflm muc mem = non-specific up resp, highly contagious
2) Paroxysmal: cough -> vomit, lasts wks
3) Convalescent: ↓ cough, 2º inf (pneumo, enceph, seizure)

Question 23

Pertussis Adhesions?

Answer 23

1) Filamentous Hemagglutinin (highly immunogenic)
2) Pertactin
3) Agglutinogens

Attach bacteria to ciliated epith cells

Question 24

Pertussis Exotoxins? (4)

Answer 24

1) A-B: inhibits phago -> causes lymphocytosis
2) Adenylate Cyclase: ↓ chemotaxis
3) Dermonecrotic: vasoconst/ischemic necrosis
4) Tracheal Cyto: kills cili epith, ↑ IL-1 release

Question 25

Pertussis Pathogenesis steps? (4)

Answer 25

1) Inhale droplets
2) Attach to cili epith -> make toxins
3) Neutro influx, epith damages, ↑ mucus
4) Compromised small airways

Question 26

Pertussis Epidemiology?

Answer 26

human dz
(U) < 1yo
endemic w/ occasional epidemics

Question 27

Pertussis Dx: Presumptive?

Pertussis Dx: Definitive?

Answer 27

Serology: ELISA (Ig), 4x ↑ in paired sera or initial titer

Cx: Bordet-Geng, Regan-Lowe agar
PCR

Question 28

Pertussis tx?

Answer 28

DOC for tx/prophy for non-immunized: Erythro

Vaccine