Vibrio parahaemolyticus is a Gram-negative halophilic bacterium that is found in estuarine, marine and coastal environments. V. parahaemolyticus is the leading causal agent of human acute gastroenteritis following the consumption of raw, undercooked, or mishandled marine products.
3. GENERAL CHARACTERISTICS
Endospore – Absent
Respiration – Facultative anaerobic
Optimum temperature - 30 to 35°C
Optimum pH - 6.8 to 10.2
Habitat – Ubiquitous marine bacterium
Mainly found in the free – living sea water and marine
environments.
Organisms are Halophilic (Salt- loving)
Discovered – Tsunesaburo Fujino in 1950
4. SCIENTIFIC CLASSIFICATION
Domain – Bacteria
Family – Vibrionaceae
Order – Vibrionales
Phylum – Pseudomonodota
Scientific name – Vibrio
parahaemolyticus
12. PATHOGENESIS
Infection usually occurs through the fecal-oral route and
adheres to the host cell
Thermostable direct hemolysin (tdh) causes lysis of
human erythrocyte cells
Vibrio parahaemolyticus also forms a toxin for its
enzymatic activity
Tdh is responsible for causing toxicity of cells
As the osmotic pressure increases in the cell its morphology
and self regulation will expand and eventually die.
16. CLINICAL DISEASES
1. Gastro-enteritis
• Digestive problem
• Lasts for 2 days
• Treated with antibiotics
3.Woundinfection
• Bacteria enter and
multiplies inside
wounds
2. Bacteremia
• Present in the
blood
20. BIO CHEMICAL TESTS
Catalase test- Positive (Bubbles formation)
Oxidase test – Positive ( Blue)
Urease test- Positive (Pink)
Indole test – Positive (Pinkish red)
Methyl red test – Positive (Red)
Voges proskauer test – Negative (Pinkish red)
Nitrate reduction test – Positive (Pinkish red)
H2s production – Negative ( Black)
Triple sugar iron test – Positive ( Yellow butt and red slant)
