LAB 11 – HAEMOPHILUS, BORDETELLA, PASTEURELLA, BRUCELLA Flashcards

1
Q

How does a staph streak allow Haemophilus to grow on a BAP?

A
  • S. aureus lyse RBCs to produce hemin (x factor) and NAD (v factor)
  • Haemophilus sp. will satellite

NAD - nicotinamide adenine dinucleotide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why does H. influenzae only grow around the disc with both X and V factor?

A
  • requires both exogenous x and v
    (ie. hemin and NAD, respectively)

NAD - nicotinamide adenine dinucleotide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where would you incubate a plate with Bordetella pertussis?

A

O2; strict aerobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why does sheep blood not support the growth of Haemophilus sp.? Why can they grow
on CAP using sheep’s blood?

A
  • Haemophilus sp. require both x and v factors
  • NADase in BAP breaks down NAD (v factor) needed
  • CAP has been heated; RBCs release hemin (x factor) and NADase is inactivated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is special about the staining of Pasteurella multocida?
a. What stain is this most commonly seen with?

A

bipolar g-cb on Giemsa stain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are X and V factors?

A

X factor = hemin; an iron porphyrin
V factor = NAD

NAD - nicotinamide adenine dinucleotide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does the ALA test determine? What is it testing for?

A

delta-AminoLevulinic Acid test:
- determines whether organism requires exogenous x factor
- tests organism’s ability to produce its own hemin

Results: Red fluorescence under UV = (+) porphyrin
No fluorescence = (-) porphyrin

NOTE: also called Porphyrin test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Appropriate specimens for Haemophilus sp.?

A
  • blood
  • sputum
  • CSF
  • conjunctival and genital ulcer swabs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What cautions have to be taken with Brucella spp.?

A
  • Biosafety level 3 protocols
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is brucellosis usually diagnosed?

A
  • based on detection of serum antibodies (1:160 titre), rather than isolation of organism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What antibiotic does H. influenzae have a high resistance to? Why?
a. Which specimens are screened for this antibiotic resistance?

A
  • High ampicillin resistance (β-lactamase)
    a. primary cultures from blood and CSF are screened via chromogenic cephalosporin method
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Specimen type for Bordetella and any special collection instructions?

A
  • nasopharyngeal swabs collected using a tiny calcium alginate swab
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What effects are B. pertussis highly susceptible to?
a. What media is required to isolate?

A
  • fragile specimens susceptible to toxic unsaturated fatty acids, peroxides and sulfides
    a. requires charcoal or starch and high concentrations (10-20%) of blood for primary isolation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the following results for Pasteurella multocida?
a. Gram
b. Colonial morph
c. Catalase
d. Oxidase
e. Spot indole
f. Nitrate
g. Ornithine decarboxylase
h. Urease
i. Motility
j. TSI

A

a. Gram = g-cb, bipolar
b. Colonial morph = muc, gy sm, translucent
c. Catalase = (+)
d. Oxidase = (+)
e. Spot indole = (+)
f. Nitrate = (+)
g. Ornithine decarboxylase = (+)
h. Urease = (-)
i. Motility = (-)
j. TSI = wk A/A

NOTE: no growth on MAC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the results for the following tests for Brucella abortus?
a. Gram
b. Colonial morphology
c. Urease
d. Oxidase
e. Catalase
f. Nitrate

A

a. Gram = g-cb
b. Colonial morphology = sm gy, translucent
c. Urease = (+)
d. Oxidase = (+)
e. Catalase = (+)
f. Nitrate = (+)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly