This Vibrio Chromogenic Medium is a dehydrated powder formulation designed for the rapid detection, isolation, and differentiation of Vibrio species from seafood, water, and environmental samples. It is particularly effective for the presumptive identification of Vibrio parahaemolyticus (a leading cause of seafood-borne gastroenteritis) and Vibrio cholerae (the causative agent of cholera).
The medium utilizes specific chromogenic substrates that are cleaved by unique enzymes produced by different Vibrio species. This creates a clear color differentiation:
- Vibrio parahaemolyticus develops blue-green colonies.
- Vibrio cholerae develops red colonies.
This differential color reaction allows laboratories to presumptively identify and differentiate these important pathogens within 18–24 hours, significantly accelerating testing workflows compared to traditional culture and biochemical methods.
The high nutrient content (60g/L recombinant peptone) and specific pH (8.6) create an alkaline environment that favors the growth of Vibrio species while inhibiting many competing organisms.
Intended Use
- Rapid detection and differentiation of Vibrio parahaemolyticus and Vibrio cholerae.
- Microbiological examination of seafood, shellfish, and marine products.
- Water and environmental testing in coastal and aquaculture areas.
- Food safety and hygiene verification.
- Research and educational laboratory applications.
Composition (per 1000 mL, as Dehydrated Basis)
- Recombinant Peptone: 60.0 g
- Comprehensive Nutrients: 15.0 g
- Chromogenic Reagent: 4.5 g
- Agar: 15.0 g
- Final pH: 8.6 ± 0.2 at 25°C
Quality Control (Growth Performance)
Validated at 36 ± 1°C for 18–24 hours:
- Vibrio parahaemolyticus ATCC 17802 (30–100 CFU): Growth rate ≥85%; blue-green colonies.
- Vibrio cholerae non-O1 Vb0 (30–100 CFU): Growth rate ≥85%; red or light red colonies.
- Escherichia coli ATCC 25922 (30–100 CFU): Little to no growth; colorless or white colonies.
- Staphylococcus aureus ATCC 25923 (10⁴–10⁵ CFU): Completely inhibited.
Physicochemical Properties
- Appearance: Powder – light yellow; Prepared plate – light yellow.
- Moisture (Powder): ≤5%
- pH: 8.6 ± 0.2
- Gel Strength: 550–650 g/cm²
Storage and Shelf Life
- Format: 94.5 g/bottle, dehydrated powder.
- Shelf Life: 2 years from date of manufacture (standard for dehydrated media; confirm with your supplier if different).
- Storage: Store in a dry, dark place at 2–8°C. Keep tightly closed to prevent moisture absorption.
Q: What is Vibrio Chromogenic Medium used for?
A: It is used for the rapid detection, isolation, and differentiation of Vibrio species, particularly Vibrio parahaemolyticus and Vibrio cholerae, in seafood and environmental samples.
Q: How do I differentiate the Vibrio species on this plate?
A: Vibrio parahaemolyticus forms blue-green colonies, while Vibrio cholerae forms red or light red colonies. This differentiation is based on specific enzymatic reactions with the chromogenic substrates in the medium.
Q: How quickly can results be obtained?
A: Presumptive Vibrio colonies appear after incubation at 36 ± 1°C for 18–24 hours.
Q: How do I prepare the medium?
A: Weigh 94.5 g of powder, add to 1,000 mL of distilled water, heat to boiling until dissolved, cool to 50–55°C, and pour plates. No autoclaving is required for this medium (as per the provided instructions).
Q: What is the shelf life and storage condition for the dehydrated powder?
A: The shelf life is 2 years from the date of manufacture when stored at 2–8°C in a dry, dark place. Keep the bottle tightly closed to prevent moisture uptake.
Q: How should I dispose of the plates after use?
A: This is a single-use product. After use, plates must be disposed of as biohazardous waste. Autoclave the plates before final disposal.
