NON-BRANCHING, NON-SPOREFORMING, Gram Positive, Catalase POSITIVE Bacilli

Question 1

primary transmission of C. diphtheriae

Answer 1

resiratory secretions or exudates from skin lesions

Question 2

virulence factor of Listeria monocytogenes

Answer 2

the ability to survive within phagocytes

Question 3

the four biotyoes of C. diphtheriae

Answer 3

gravis
intermedius
belfanti
mitis

BIG M

** distinguished based on phenotypic characteristics (Size, texture, color, hemolysis and the presence of metachromatic granules)

Question 4

mode of transmission of Listeria monocytogenes

Answer 4

ingestion of contaminated food - meat and dairy products

Question 5

the hemolytic and cytotoxic toxin that allow L. monocytogenes to survive inside phagocytes

Answer 5

Listeriolysin O

Question 6

cell surface prootein in L. monocytogenes that induces phagocytosis

Answer 6

internalin

Question 7

cmponent in L. monocytogenes that induces actin polymerization on the surface of host cells in order to facilitate cell to cell infection

Answer 7

Act A

Question 8

allowsL. monocytogenes to scavenge Iron from hman transferrin

Answer 8

siderophores

Question 9

a potent EXOtoxin in C. diphtheriae that destroys host cells by inhibiting protein synthesis

Answer 9

Diphtheria toxin

Question 10

tthe up and coming cause of cystitis in hospitalized patient, in those that have undergone urologic manipulation and in the elederly

Answer 10

Corynebacterium urealyticum

Question 11

specimen pocessing of L. monocytogenes from placental and other tissues

Answer 11

cold enrichment

4C in nutrient broth for several weeks to months then subcultured to enhance recovery

Question 12

microscopic arrangement of C. diphtheriae

Answer 12

palisades arrangement (L or V form)

Question 13

media of choice for C. diphtheriae

Answer 13

BAM
CAM
*** BAM 1% Tween 80 – for lipophilic Corynebactrium

SELECTIVE AND DIFFERENTIAL AGAR:
- Cystine-Tellurite Agar: Cystine enhances the growth of fastidious organisms

• Modified Tinsdale Agar (TIN)
• ** both agars have high POTASSIUM TELLURITE to inhibit he growth of normal flora
• — results to brown-black colonies

Question 14

colonial morphology of C. diphtheriae on Tinsdale agar

Answer 14

brown colonies with HALO

Question 15

culture media where C. diphtheriae growth and production of METACHROMATIC GRANULES is stimulated

Answer 15

Loeffler medium

Question 16

pH wherein coryneforms are most likely to cause urinary tract infections

Answer 16

alkaline pH

if struvite crystals are present (phospate, magnesium and ammonia) in the sediment

Question 17

other laboratory findings for C. diphtheriae

Answer 17

esculin negative

gelatin negative

Question 18

motility of L. monocytogenes

Answer 18

tumbling motility on wet mount

umbrella shaped pattern in semi-solid media

Question 19

bacteria that is also isolated from patients with bacterial vaginosis

Answer 19

Corynebacterium lipophiloflavum