moraxella

Question 3

Moraxella catarrhalis — Gram stain

Answer 3

Gram-negative diplococci (indistinguishable from Neisseria on Gram stain)

Question 4

Moraxella catarrhalis — Family

Answer 4

Moraxellaceae

Question 5

Moraxella catarrhalis — Oxygen requirement

Answer 5

Strict aerobe

Question 6

Moraxella catarrhalis — Motility

Answer 6

Non-motile

Question 7

Moraxella catarrhalis — Spore forming

Answer 7

Non–spore forming

Question 8

Moraxella catarrhalis — Key enzymes

Answer 8

Oxidase +, catalase +, DNase +

Question 9

Moraxella catarrhalis — Maltose fermentation

Answer 9

Negative

Question 10

Moraxella catarrhalis — Colonization site

Answer 10

Upper respiratory tract (nasopharynx)

Question 11

Moraxella catarrhalis — Hosts

Answer 11

Humans are the only hosts

Question 12

Moraxella catarrhalis — Transmission

Answer 12

Respiratory droplets

Question 13

Moraxella catarrhalis — Colonization pattern

Answer 13

Common in infancy; decreases with age

Question 14

Moraxella catarrhalis — When colonization is higher

Answer 14

Winter months

Question 15

Moraxella catarrhalis — Key step to start infection

Answer 15

Adherence to respiratory epithelium

Question 16

Moraxella catarrhalis — “Hockey puck sign”

Answer 16

Colonies slide across agar when pushed

Question 17

Moraxella catarrhalis — Culture growth

Answer 17

Grows on blood agar and chocolate agar

Question 18

Moraxella catarrhalis — Main infection type

Answer 18

Mucosal infections (contiguous spread from colonization site)

Question 19

Moraxella catarrhalis — Classic pediatric disease

Answer 19

Otitis media

Question 20

Otitis media (Moraxella) — Route

Answer 20

Nasopharynx → middle ear via Eustachian tube

Question 21

Otitis media (Moraxella) — What’s usually needed to trigger

Answer 21

Viral respiratory infection (inciting event) in a colonized child

Question 22

Moraxella catarrhalis — Otitis media prevalence (culture)

Answer 22

~5–20% of cases

Question 23

Moraxella catarrhalis — Otitis media detection in middle-ear fluid (alone or with others)

Answer 23

~30–50% of samples

Question 24

Moraxella catarrhalis — Important adult setting

Answer 24

COPD

Question 25

COPD (Moraxella) — Key pathogenesis point

Answer 25

Acquisition of a new strain is critical

Question 26

Moraxella catarrhalis — Causes what fraction of COPD exacerbations?

Answer 26

~10%

Question 27

COPD exacerbation symptoms linked to Moraxella

Answer 27

Increased cough + sputum, increased sputum purulence, increased dyspnea vs baseline

Question 28

Moraxella catarrhalis — Pneumonia in older adults usually with

Answer 28

Underlying COPD, CHF, or diabetes

Question 29

Moraxella catarrhalis — Fulminant pneumonia

Answer 29

Common or uncommon?

Question 30

Moraxella catarrhalis — Sinusitis ranking

Answer 30

3rd most common cause (after nontypeable H. influenzae and S. pneumoniae)

Question 31

Moraxella catarrhalis — LOS (lipooligosaccharide) effect

Answer 31

Induces proinflammatory cytokines via TLR4 and CD14 pathways

Question 32

Moraxella catarrhalis — MID/Hag protein effect

Answer 32

Mitogenic for B lymphocytes

Question 33

Moraxella catarrhalis — UspA2 effect

Answer 33

Regulates NF-κB → increases IL-8 release by respiratory epithelial cells

Question 34

Moraxella catarrhalis — Surface vesicles do what?

Answer 34

B-cell activation, induction of inflammation, delivery of β-lactamase

Question 35

Moraxella catarrhalis — Immune evasion binding targets

Answer 35

Binds ECM molecules (vitronectin, fibronectin, collagen, plasminogen, cartilage oligomeric matrix protein)

Question 36

Moraxella catarrhalis — Biofilm significance

Answer 36

Protects against host immune responses

Question 37

Moraxella catarrhalis — IgA protease

Answer 37

Produced

Question 38

Moraxella catarrhalis — β-lactamase production

Answer 38

Majority produce β-lactamases (BRO-1, BRO-2, BRO-3)

Question 39

Moraxella catarrhalis — β-lactam resistance implication

Answer 39

Resistant to ampicillin and penicillin

Question 40

Moraxella catarrhalis — Treated with (typical)

Answer 40

Amoxicillin/clavulanic acid

Question 41

Moraxella catarrhalis — Other options (susceptible to)

Answer 41

Macrolides, fluoroquinolones, extended-spectrum cephalosporins

Question 42

Moraxella catarrhalis — Routine etiologic diagnosis

Answer 42

Usually not done; treated empirically based on clinical picture

Question 43

Moraxella catarrhalis — How to diagnose if needed

Answer 43

Culture, Gram stain, PCR

Question 44

Moraxella catarrhalis — Vaccine

Answer 44

No vaccines currently available