17. vibrio genus. plesimonas and aeromonas

Question 1

Vibrionacae family

Answer 1

most important group is vibrio genus (vibrio cholera

Question 2

morphology

Answer 2

1) Gram - CURVED shaped rod

2) Motile- flagella

Question 3

biochemical char/ general char:

Answer 3

1) Oxidase positive
2) catalase positive
3) Halofil (likes salt… would be smart to remember in relation to mainly found in water)
4) Facultative anerob.
5) OBLIGATE HUMAN PATHOGEN

Question 4

Serological identification (and classifcation):

Answer 4

Serological identification: slide agglutination with specific anti-‘O’ / > 140 test serum (antibodies).

1) Serotypes O 1, O 139 => pandemic cholera
2) O 2- O 138 => non-severe enteritis.

O1 has biotypes: Classic and el-toro, which are further devided to 3 serotypes: Ogawa, Inaba and hikojima.

Question 5

source, transmission, pathogenesis

Answer 5

Source: drinking water (>108), food
Dr. John Snow found by.
Disease association: endemic and pandemic cholera Pathogenesis: pathogenic only for humans!
1. spread by consumption of contaminated food or water: Oral route ( 10^9 – 10^10organisms) adherence to the epithelial cells of the small intestine, multiplication here

Question 6

Labratory diagnostics:

1) Specimen from!?
2) Microscopy (2 examples)
3) Culture? (special media!)

Answer 6

Clinical specimen: mucous flecks from stools, drinking water, food
Microscopy:
1) Direct smear: not distinctive, but dark field, or phase contrast microscopy may show rapid movement of V. cholerae cells.
2) Smear taken from broth culture and stained by Gram shows a comma-shaped.

Culture:
• Selective medium: TCBS medium, Colonies: convex, smooth, round shaped yellow.

Question 7

Biochemistry diagnostics!

Answer 7

• Oxidase+ (which is very important, because it differentiates it from Enterobacteriaceae)

Question 8

serological diagonostics!

Answer 8

Serological identification: slide agglutination with specific anti-‘O’

Question 9

Treatment of cholera.
Important treatement! (2 ways!)
Antibiotics?! 1 example!

Answer 9

1. Most importantly, water and electrolyte replacement therapy should be started as soon as possible to correct severe dehydration and electrolyte loss. Ways of rehydration: •
   1) a) intravenous infusions.
   1b) ORF (oral rehydration fluid).
2. tetracyclines (doxycyclin) or ciproflaxacin.

Question 10

Cholera prophylaxis!

4 examples.

Answer 10

1. good hygine.. wash your damn hands.
2. Separation from the contaminated patients.
3. Education about good sanitation (. Boiling of drinking water and disinfecting of vegetables and fruits in endemic areas. )

4) Vaccination: Inactivated per os vaccine, with
promotion of IGA production.
Live attenuated also exists.
Only 50% protection and several months!

• Chemoprofilaxis with tetracyclines may have a role in prevention.

Question 11

Vibrio parahaemolyticus.

Answer 11

Not properly cooked seafood – 90% oysters! (Far-Eastern cuisine)
leading pathogen of diarrhoea cases in Japan
self-limited, but severe gastroenteritis
enterotoxin
incubation time ~ 24 h

Question 12

Aeromonas (A. hydrophila)

4 general things characters!

Answer 12

Gram negative
facultative
anaerobic rod,
oxidase +

Question 13

Aeromonas (A. hydrophila)
Who does it affect and how?
Symptoms!
How to treat!

Answer 13

• opportunistic systemic disease in immunocompromised patients:
• diarrhoeal disease (bloody diarrhoea) – from contaminated food, water -
  wound infections (cellulitis) – from contaminated water
  Treatment:ciprofloxacin

Question 14

Plesiomonas (P. shigelloides)

Answer 14

Plesiomonas (P. shigelloides)

Motile, Gram-negative, oxidase positive - seafood - gastroenteritis (watery or bloody)