7. Aerobic Gram-positive Bacilli

Question 1

Spore forming aerobic gram-positive bacilli

Answer 1

Bacillus spp.

Question 2

Non-spore forming aerobic gram-positive bacilli

Answer 2

Listeria
Erysipelothrix
Corynebacterium

Question 3

Bacillus spp. are found in

Answer 3

Soil

Question 4

True/False. Only some Bacillus spp. form endospores.

Answer 4

False

ALL species of Bacillus form endospores

Question 5

Catalase reaction of Bacillus spp.

Answer 5

Catalase positive

Question 6

Bacillus spp. that is commonly associated with food poisoning

Answer 6

Bacillus cereus

Question 7

Type of food poisoning that is from meat, 24 hours, self-limiting

Answer 7

Diarrheal

Question 8

Type of food poisoning from fried rice, 10 hours, self limiting

Answer 8

Emetic

Question 9

Produced by B. cereus that causes the food poisoning

Answer 9

Toxin

Question 10

Colony morphology of B. cereus

Answer 10

Large
Spreading
β-hemolytic

Question 11

Catalase reaction of B. cereus

Answer 11

Catalase positive

Question 12

Most common disease cause by B. cereus

Answer 12

Food poisoning

Question 13

Most virulent Bacillus spp.

Answer 13

B. anthracis

Question 14

How do humans acquire B. anthracis?

Answer 14

Contact with anthrax-infected animals or animal products (no person-to-person spread)

Question 15

Clinical presentation of B. anthracis

Answer 15

Anthrax

Question 16

3 forms of Anthrax

Answer 16

Cutaneous
Inhalation
Gastrointestinal

Question 17

Anthrax form that is most commonly encountered in naturally occuring cases

Answer 17

Cutaneous

Question 18

Incubation period of cutaneous anthrax

Answer 18

1-12 days

Question 19

Anthrax form that begins as a “viral-like” illness

Answer 19

Inhalation anthrax

Question 20

Incubation period of inhalation anthrax

Answer 20

1-7 days

Question 21

Anthrax form that exhibits abdominal distress, usually accompanied by bloody vomiting or diarrhea

Answer 21

GI anthrax

Question 22

True/False. Recovery from Anthrax confers immunity.

Answer 22

True

Question 23

Antibiotics used after exposure to anthrax

Answer 23

Ciprofloxacin

Tetracycline

Question 24

Colony morphology of Bacillus anthracis

Answer 24

Medium to large irregular
Gray
Medusa head projections, non hemolytic

Question 25

Catalase reaction of Bacillus anthracis

Answer 25

Catalase positive

Question 26

Microscopic chracteristics of Listeria spp.

Answer 26

Gram-positive short rods or coccobacilli

Question 27

What temperature can Listeria spp. grow unlike other bacteria?

Answer 27

4°C

Question 28

Most virulent Listeria spp.

Answer 28

Listeria monocytogenes

Question 29

Disease caused by L. monocytogenes

Answer 29

Listeriosis

Question 30

Habitat of Listeria spp.

Answer 30

Soil | Decaying vegetation

Question 31

True/False. Listeriosis can be passed onto the fetus

Answer 31

True

Question 32

Colony morphology of L. monocytogenes

Answer 32

β-hemolytic Umbrella pattern motility Growth at 4°C

Question 33

Most clinically significant Erysipelothrix spp.

Answer 33

Erysipelothrix rhusiopathiae

Question 34

Disease caused by E. rhusiopathiae; a cutaneous infection in humans occasionally acquired by contact with infected animals

Answer 34

Erysipeloid

Question 35

Microscopic appearance of E. rhusiopathiae

Answer 35

Small gram-positive bacilli occuring singly/short chains/filaments

Question 36

Oxygen requirements of E. rhusiopathiae

Answer 36

Aerobic/facultative anaerobic

Question 37

Catalase reaction of E. rhusiopathiae

Answer 37

Catalase negative

Question 38

Specimen of choice for E. rhusiopathiae

Answer 38

Skin biopsy

Question 39

Gram stain appearance of suspect lesion for E. rhusiopathiae

Answer 39

Pleomorphic gram-positive Bacillus

Question 40

Agar used to cultivate E. rhusiopathiae

Answer 40

SBA with 5-10% CO2

Question 41

H2S reaction of E. rhusiopathiae on TSI slant

Answer 41

H2S positive

Question 42

Microscopic appearance of Corynebacterium spp.

Answer 42

Small gram-positive bacilli | May resemble Chinese letters

Question 43

Chracteristic colonial morphology of Corynebacterium spp.

Answer 43

Dry

Question 44

Most significant Corynebacterium human pathogen

Answer 44

Corynebacterium diphtheriae

Question 45

Produced by C. diphtheriae that causes death of eukaryotic cells and tissues by inhibition of cell protein synthesis

Answer 45

Exotoxin

Question 46

Vaccine for C. diphtheriae which maintains the antigenicity of the toxin without the toxicity and prompts production of toxin-neutralizing antibody

Answer 46

Toxoid

Question 47

General media for C. diphtheriae

Answer 47

5% SBA

Question 48

Selective medium for C. diphtheriae

Answer 48

Cystine-tellurite medium (CTBA)

Question 49

Colony morphology of C. diphtheriae in CTBA

Answer 49

Black to gray

Question 50

Differential medium for C. diphtheriae

Answer 50

Tinsdale

Question 51

Colony morphology of C. diphtheriae in Tinsdale medium

Answer 51

Black with brown halos

Question 52

Urease reaction of C. diphtheriae

Answer 52

Urease negative

Question 53

Nitrate reaction of C. diphtheriae

Answer 53

Nitrate positive

Question 54

Catalase reaction of C. diphtheriae

Answer 54

Catalase positive

Question 55

Corynebacterium spp. important in nosocomial or immunocompromised people

Answer 55

C. jeikeium

Question 56

Corynebacteria count that is significant in urine specimens

Answer 56

>10^4 CFU/mL

Question 57

Genera under aerobic gram-positive bacilli

Answer 57

Bacillus Listeria (+Erysipelothrix) Corynebacterium