Listeria, Corynebacterium

Question 1

Aerobic or facultative anaerobic fastidious organisms that may demonstrate slow growth on enriched medium

Answer 1

Corynebacterium spp

Question 2

How is C. diptheriae transmitted

Answer 2

Respiratory secretions and exudates from skin lesions

Question 3

Facultative anaerobic
Catalase +
Nonbranching
Oxidase –
G+rod

Answer 3

L. monocytogenes

Question 4

Major virulence factor of L. monocytogenes which reduces T-cell responsiveness

Answer 4

Listeriolysin O

Question 5

Capable of vertical transmission (Mother to fetus occurs transplacentally or through an infected birth canal), and cross infection (Identified in neonatal nurseries)

Answer 5

L. monocytogenes

Question 6

Listeria enrichment broth for stool samples

Answer 6

Polymyxin- Acriflavine-Lithium Chloride-Ceftazidime esculin- mannitol (PALCAM)

Question 7

Incubation requirement for isolation of L. monocytogenes from placental and other tissue

Answer 7

Incubated at 4C (cold enrichment)

Question 8

Singly in PALISADES of parallel cells or in pairs of cells connected after cell division to form V or L shapes. CHINESE LETTERS.

Answer 8

C. diptheriae

Question 9

Quantitative detection of L. monocytogenes in food products

Answer 9

PCR techniques

Question 10

Gene that encodes listeriolysin O in CSF and tissue (fresh or paraffin) which is detected in PCR techniques

Answer 10

HLY gene

Question 11

Culture media for Corynebacterium spp

Answer 11

BAP, CAP
Selective and differential media: cystine-telluride blood agar, modified Tinsdale agar (TIN)
Broth: thioglycollate, BHI

Question 12

Differentiate L. monocytogenes from other Listeria spp.

Answer 12

Brilliance Listeria agar base

Question 13

L. monocytogenes in brilliance listeria agar base

Answer 13

blue-green colony surrounded by opaque white halo

Question 14

Corynebacterium spp. in modified Tinsdale agar (TIN)

Answer 14

Gray to black colonies

Question 15

Brown black colonies with gray-brown halo on Tinsdale agar

Answer 15

C. diptheriae

Question 16

End-over-end tumbling motility in a wet mount/incubated incubated in nutrient broth @ RT 1-2 hrs

Answer 16

L. monocytogenes

Question 17

Umbrella motility seen which develops overnight at RT stabbed into tube of semi solid agar

Answer 17

L. monocytogenes

Question 18

colonies are small and white with a narrow zone of beta-hemolysis.

Hippurate hydrolysis, CAMP test, esculin, and catalase positive

Answer 18

L. monocytogenes

Question 19

Closely resembles group B streptococci on SBA

Answer 19

L. monocytogenes