L39

Question 1

Haemophilus influenzae

• GP or GN
• Shape
• Encapsulated or not?

Answer 1

GN
Coccobacilli
Both encapsulated and not
- Non-encapsulated are not typable 
- Encapsulated type b (Hib) is predominant

Question 2

What medium do you grow H.influ on? What factors are required?

Answer 2

Chocolate agar
Factor X = hemin
Factor V = NAD

Question 3

Where in the body does H.influ colonize?

Answer 3

Nasopharynx

Question 4

What kind of diseases do unencapsulated H.influ cause?

Answer 4

Respiratory tract

• Otitis media
• Sinusitis
• Pneumonia, bronchitis

Question 5

What kind of diseases do encapsulated H.influ (type B) cause?

Answer 5

Systemic disease via blood

• Meningitis
• Sepsis
• Septic arthritis

Question 6

What 3 virulence factors do both encap/un-encap H.influ share?

Answer 6

1. Adherence factors
   - Pili
   - Adhensins, especially in un-encap
2. LOS
3. Biofilm

Question 7

Drugs to treat H.influ non-invasive infections (un-encapsulated)

Answer 7

Amoxicillin

Amox-clavulanate if resistant

Question 8

Drugs to treat invasive H.influ infections (encapsulated, meningitis)

Answer 8

Ceftazidime/ceftriaxone (3rd gen cephalo)

Question 9

Which strain of H.influ does the vaccine target?

Answer 9

Encapsulated
Conjugated to a protein
PRP - TT, DT, OMP

Question 10

Moraxella catarrhalis

• GP or GN
• Shape

Answer 10

GN

Coccobacilli

Question 11

What 3 diseases does moraxella cause?

Answer 11

Otitis media
Sinusitis
Conjunctivitis - usually w/o symptoms even if it happens

Question 12

Drugs for moraxella

Answer 12

Amox-clavu

Cephalosporins

Question 13

Legionella pneumophila

• Shape on lab media
• Shape in tissues
• GN or GP

Answer 13

GN
Poor staining
Lab media = long, thin bacilli
Tissues = short coccobacilli

Question 14

How is legionella spread?

Answer 14

Aerosols

NOT person to person

Question 15

Risk factors for legionella

Answer 15

Smoking - chronic lung disease
Old
Immune compromised
Cancer

Question 16

What are the 2 diseases caused by legionella?

Answer 16

Pontiac Fever

Legionnaires Disease

Question 17

Symptoms of Pontiac Fever. Treatment.

Answer 17

YOUNG, HEALTHY ADULTS
Flu-like
No antibiotics needed

Question 18

What are the 3 steps of legionella pathogenesis?

Answer 18

1. Attach & enter alveolar macrophages
   - IFNg cell macrophage immunity
2. Form & target vaculoes
3. Intracell replication and cell lysis

Question 19

How does legionella survive in macrophage vacuoles?

Answer 19

Type 4 secretion system:
X phago-lysosome fusion
Vacuole w/ ribosomes (“ER like”) because site of replication

Question 20

Which stain do you use for legionella?

Answer 20

Gimenez for smears

Dieterle for tissues

Question 21

Which medium do you culture legionella on?

Answer 21

Buffer charcoal yeast medium

Question 22

Which 2 tests can you order to diagnose ligionella?

Answer 22

1. Urine antigen test
   Detects most common strand’s LPS
2. Sputum direct fluorescent Ab test

Question 23

Drugs for legionella

Answer 23

Pneumonia:
- Fluoro
- Macrolide
Legionnaires - azithromycin

Question 24

Coxiella burnetti

• GP or GN
• Shape
• Unique attributes

Answer 24

GN
Bacillus - OBLIGATE INTRACELL (!!!)
Low infectious dose - carries by farm animals

Question 25

Acute vs chronic diseases caused by coxiella burnetti

Answer 25

Acute = Q fever - Flu-like Chronic = endocarditis

Question 26

Drug coxiella burnetti

Answer 26

Doxycycline

Question 27

Bordetella pertussis - GN or GP - Shape - Aerobic vs anaerobic

Answer 27

GN Coccobacilli NO polysacc capsule Aerobic

Question 28

How do you diagnose B.pertussis?

Answer 28

PCR (replaced plate cultures) | Serology

Question 29

How is B.pertussis spread?

Answer 29

Highly contagious | Aerosols

Question 30

4 stages of pertussis disease

Answer 30

1. Incubation 2. Catarrhal - cold 3. Paraoxysmal - whooping cough 4. Convalescent - resolving

Question 31

Why do kids die from whooping cough?

Answer 31

Respiratory failure

Question 32

What are the 3 toxins made by B.pertussis?

Answer 32

Pertussis toxin Adenylate cyclase toxin Tracheal toxin

Question 33

Fxn of pertussis toxin

Answer 33

Ribosylates inhibitory G proteins Net = lymphocytosis B/c chemokine receptors of WBCs disabled --> stay in blood stream Why get systemic symptoms & poor outcomes for kids

Question 34

Fxn of tracheal toxin

Answer 34

Damages ciliated respiratory epithelium

Question 35

Drug B.pertussis

Answer 35

Azithromycin - only to prevent spread, doesn't help symptoms

Question 36

What is the pertussis vaccine? Cons?

Answer 36

``` DTaP Diphtheria Tetanus Acellular pertussis Cons: need boosters b/c immunity wanes ```