GRAM-NEGATIVE COCCOBACILLI

Question 1

Bacteria included in the gram-negative coccobacilli classification:

Answer 1

1. Haemophilus
2. Bordetella
3. Legionella
4. Gardnerella

Question 2

H. influenzae is also known as:

Answer 2

Pfeiffer’s bacillus

Question 3

How many serological types does H. influenzae have that have polysaccharide capsules?

Answer 3

6 serological types (a, b, c, d, e, f)

Question 4

Most common H. influenzae serological type that causes meningitis in infants under 2 years of age in the U.S

Answer 4

Type b

Question 5

Type b causes:

Answer 5

• epiglotittis (“cherry red’ epiglotittis)
• pneumonia
• cellulitis
• otitis media

Question 6

H. influenzae can produce IgA protease

True or False:

Answer 6

True

mnemonic: ‘SHiNeNe”
- S. pneumoniae
- H. influenzae
- Neisseria gonorrhoeae
- Neisseria meningitidis

Question 7

H. aegyptius (now part of Haemophilus) is also known as:

Answer 7

Koch-Weeks bacillus

Question 8

H. aegyptius causes “_______” conjunctivitis

Answer 8

“pink eye” conjunctivitis

Question 9

Haemphilus species that are considered normal flora in the upper respiratory tract:

Answer 9

1. H. haemolyticus
2. H. parahemolyticus
3. H. parainfluenzae; others

Question 10

Cause of ulcerative chancroid, an STD seen as a painful genital ulcer:

Answer 10

H. ducreyi

Question 11

Cause of ulcerative chancre, an STD seen as a painless genital ulcer:

Answer 11

Primary syphilis

Question 12

H. ducreyi in gram stain is described as “____________________” appearance

Answer 12

H. ducreyi in gram stain:

“school of fish” appearance

Question 13

Colony appearance of Haemophilus influenzae:

Answer 13

Dew-drop colonies

Question 14

Haemophilus species require ____ and/or _____ factors

Answer 14

X and/or V factors

Question 15

Agar that supplies both X and V factors:

Answer 15

Chocolate agar

Question 16

A phenomenon where Haemophilus colonies grow more luxuriously next to Staphylococcus streak:

Answer 16

“Satellite phenomenon”

Question 17

Haemophilus requirements:

H. influenzae:
- X factor (?)
- V factor (?)
- Hemolysis (?)
- ALA (?)

Answer 17

H. influenzae:
- X factor (+)
- V factor (+)
- Hemolysis (-)
- ALA (-)

Question 18

Haemophilus requirements:

H. aegyptius:
- X factor (?)
- V factor (?)
- Hemolysis (?)
- ALA (?)

Answer 18

H. aegyptius:
- X factor (+)
- V factor (+)
- Hemolysis (-)
- ALA (-)

Question 19

Haemophilus requirements:

H. haemolyticus:
- X factor (?)
- V factor (?)
- Hemolysis (?)
- ALA (?)

Answer 19

H. haemolyticus:
- X factor (+)
- V factor (+)
- Hemolysis (+)
- ALA (-)

Question 20

Haemophilus requirements:

H. parahaemolyticus:
- X factor (?)
- V factor (?)
- Hemolysis (?)
- ALA (?)

Answer 20

H. parahaemolyticus:
- X factor (-)
- V factor (+)
- Hemolysis (+)
- ALA (+)

Question 21

Haemophilus requirements:

H. parainfluenzae
- X factor (?)
- V factor (?)
- Hemolysis (?)
- ALA (?)

Answer 21

H. parainfluenzae:
- X factor (-)
- V factor (+)
- Hemolysis (-)
- ALA (+)

Question 22

Haemophilus requirements

H. paraphrophilus
- X factor (?)
- V factor (?)
- Hemolysis (?)
- ALA (?)

Answer 22

H. paraphrophilus:
- X factor (-)
- V factor (+)
- Hemolysis (-)
- ALA (+)

Question 23

Haemophilus requirements

H. ducreyi:
- X factor (?)
- V factor (?)
- Hemolysis (?)
- ALA (?)

Answer 23

H. ducreyi:
- X factor (+)
- V factor (-)
- Hemolysis (Wk+)
- ALA (-)

Question 24

Haemophilus requirements:

H. aphrophilus:
- X factor (?)
- V factor (?)
- Hemolysis (?)
- ALA (?)

Answer 24

H. aphrophilus:
- X factor (-)
- V factor (-)
- Hemolysis (-)
- ALA (+)

Question 25

Causative agent of the whooping cough; “100 day cough”

Answer 25

Bordetella pertussis

Question 26

toxin produced by B. pertussis which impairs recruitment of neutrophils

Answer 26

Pertussis toxin

Question 27

In B. pertussis infection, instead of neutrophilia, what leukocyte increases?

Answer 27

Lymphocytes (Lymphocytosis)

Question 28

Stages of pertussis:

Answer 28

• Catarrhal
• Paroxysmal
• Convalascent

Question 29

Most contagious pertussis stage:

Answer 29

Catarrhal

Question 30

Recovery stage of pertussis:

Answer 30

Convalascent

Question 31

Stage of pertussis where “whooping cough” is observed:

Answer 31

Paroxysmal

Question 32

What differentiates B. pertussis from other Bordetella species?

Answer 32

B. pertussis
- urease (-)
- nitrate (-)
- non-motile
- oxidase (-)

B. parapertusis
- urease (+ after 18 hours)

B. bronchisepta
- Urease (+)
- nitrate (+)
- motile
- oxidase 9+)

Question 33

Fastidious, gram-negative rod but does not gram stain well,; silver stains used (e.g. Dieterie stain)

Answer 33

Legionella

Question 34

best medium for Legionella:

Answer 34

Buffered Charcoal Yeast Extract Agar (BCYE)

Question 35

Legionella requires _____ and _______ for growth:

Answer 35

iron and L-cysteine

Question 36

Diseases caused by Legionella pneumophilia:

Answer 36

• Legionnaire’s disease
• Pontiac fever

Question 37

Bacteria associated with Bacterial Vaginosis; tiny fastidious rod:

Answer 37

Gardnerella vaginalis (formerly Haemophilus vaginalis)

Question 38

Culture media for G. vaginalis:

Answer 38

• V (vaginalis) agar
• HBT (human blood tween) agar (best medium for G. vaginalis)

Question 39

Vaginal epithelial cells covered with bacteria:

Answer 39

Clue cells