Exam 2 - Gram- Coccobacilli (H, L, B)

Question 1

List the 3 Gram- coccobacilli:

Answer 1

Bordetella
Legionella
Haemophilus

Question 2

This organism is capnophilic and requires X and V Factors for growth:

Answer 2

Haemophilus

Question 3

Will Haemophilus grow on SBAP:

Answer 3

little to no growth (SBAP only contains X factor)

Question 4

What is a special selective agar used to isolate Haemophilus influenzae in CF patients:

Answer 4

CAP with Bacitracin

prevents overgrowth of G+ and G- cocci

Question 5

For hemolytic strains of Haemophilus (H. haemo/parahaemolyticus), what type of agar would be need to see:

Answer 5

Horse/rabbit blood agar

Question 6

Satellite phenomenon allows for Haemophilus to grow on SBAP only if this strain is also there:

Answer 6

Staph aureus

since it lyses blood cells, releasing X factor, and it produces V factor on its own

Question 7

Is H. ducreyi normal flora:

Answer 7

No

Question 8

If you cant inoculate Haemophilus w/in 1 hour, you must use T-1 medium, why:

Answer 8

All of the species are prone to drying and temp sensitive

Question 9

T/F H. influenze has capsule containing surface antigens that can be typed:

Answer 9

True (Types a-f)

*also has non-capsulated forms, they cause less severe infection

Question 10

Which serotype of H. influenzae causes serious infections such as meningits, bacteremia, and epiglottitis:

Answer 10

Type B (90% of isolates)
(vaccine available)

Question 11

What used to be the most common cause of meningitis before its vaccine came about:

Answer 11

H. influenzae

Question 12

What is the vaccine for H. influenzae:

Answer 12

Hib

Question 13

What definitively ID’s H. influenzae:

Answer 13

ALA negative

Question 14

This organism has a school of fish appearance on Gram stain:

Answer 14

Haemophilus ducreyi

Question 15

This organism causes an STD similar to syphilis:

Answer 15

Haemophilus ducreyi

Question 16

H. ducreyi required ID via:

Answer 16

PCR

Question 17

T/F

H. ducreyi is common in the US:

Answer 17

False.

It is common in Africa, Asia, and Latin America

Question 18

This organism uses protein rather than carbs for growth:

Answer 18

Legionella pneumophilia

Question 19

This organism requires Buffered Charcoal Yeast Extract agar, and grows in the presence of L-cysteine:

Answer 19

Legionella pneumophilia

Question 20

What are the two forms of Legionella pneumophilia:

Answer 20

• Dormant, cyst like (highly infectious)

* Intracellular form (evades defenses)

Question 21

On BCYE, what will colonies of Legionella pneumophilia do:

Answer 21

fluoresce under UV light

Question 22

What is required for definitive Dx for Legionella pneumophilia:

Answer 22

Serotyping

Question 23

Is Legionella pneumophilia spread person to person:

Answer 23

No. infection occurs via inhalation of mist containing microbes.
(AC’s, humidifiers, hot tubs)

Question 24

Which organism causes Pontiac Fever:

Answer 24

Legionella pneumophilia

Question 25

List the 3 species of Bordetella:

Answer 25

B. pertussis
B. parapertussis
B. bronchiseptica

Question 26

This organism has colonies resembling mercury droplets:

Answer 26

Bordetella pertussis/parapertussis

Question 27

Does Bordetella pertussis spread person to person via resp droplets:

Answer 27

Yes

Question 28

What is required for presumptive ID of Bordetella pertussis:

Answer 28

• Mercury droplet colonies

* Growth on Regan-Lowe media

Question 29

What are the three stages of illness with Pertussis:

Answer 29

Catarrhal (7-10 days)
Paroxysmal (1-6+ wks)
Convalescent (7-10 days)

Question 30

Pertussis is contagious from the ____ stage to the 3rd week of the ____ stage:

Answer 30

Catarrhal

Paroxysmal

Question 31

This organism is the cause of kennel cough in dogs:

Answer 31

Bordetella bronchiseptica

Question 32

What media is used to grow Bordetella bronchiseptica:

Answer 32

SBAP
MacConkey
Cap

Question 33

What media is needed to grow Bordetella pertussis:

Answer 33

Bordet-Gengou
Modified Jones-Kendrick charcoal
Regan-Lowe
(will also grow on SBAP, variable growth on MacConkey)