Vibrio

Question 1

Habitat

Answer 1

Mainly in water

Question 2

General characteristics (4)

Answer 2

Short, Curved, Gram-Negative bacilli

Motile

Oxidase positive

Aerobe

Question 3

Classification (2)

Answer 3

1- Non-halophilic:
- V.cholerae

2- Halophilic:

 - V.parahemolyticus
 - V.vulnificus

Question 4

Culture (3)

Answer 4

Enrichment media: Alkaline Peptone water

Selective media: TCBS media (Thiosulphate Citrate Bile Sucrose agar) observe YELLOW colonies (SUCROSE-FERMENTING)

Oxidase test positive

Question 5

Lab Diagnosis

Answer 5

Somatic (O) antigen structure:

• V.cholerae: O1 antigen
• Non O1 V.cholerae: no O1 antigen

Question 6

Biotypes (2)

Answer 6

Classical

El tor

Question 7

Pathogenicity (6)

Answer 7

Infective dose small
Multiply in small intestine
Produce enterotoxin (cholera toxin)
Irreversible activation of cAMP
Blocks uptake of water which accompanies Na and Cl absorption
Passive movement of water leading to serious loss of water

Question 8

Clinical manifestations (4)

Answer 8

Febrile diarrheal illness (severe)
Vomitting
Rapid dehydration and Hypovolemic shock
Rice water stool (vs dysentery stool, mucopurulent)

Question 9

V.cholerae non-01 (3)

Answer 9

Mild, sometimes bloody diarrhea
May produce toxins
Cause epidemics

Question 10

V.parahemolyticus

Answer 10

ACUTE GASTROENTERITIS (FOOD POISONING)

Question 11

V.parahemolyticus- Pathogenicity (3)

Answer 11

Causes explosive diarrhea
Self-limiting (3 days)
Ingestion of sea food (shellfish and fish)

Question 12

V.parahemolyticus- Lab Diagnosis

Answer 12

SUCROSE NON-FERMENTER (GREEN)

Question 13

V.vulnificus- Habitat

Answer 13

WARM WATER environment

Question 14

V.vulnificus- Clinical manifestations (3)

Answer 14

RAPID ONSET FULMINATING SEPTICEMIA followed by CUTANEOUS LESIONS (SHELL FISH)
RAPID ONSET CELLULITIS
ACUTE DIARRHEA following consumption of SHELLFISH

Question 15

V.vulnificus- Pathogenesis (1)

Answer 15

Polysaccharide capsule