Vibrio Chromogenic Medium is used for the rapid detection of Vibrio parahaemolyticus in food, seafood, and fish in patient stool samples. The colonies of Vibrio parahaemolyticus are green and have large colonies, Vibrio cholerae are red, other Vibrio are red, blue or colorless and have small colonies, most of other bacteria are inhabited. The medium has a high specificity, can overcome false negative results caused by TCBS medium, therefore, it is an ideal culture medium for rapid detection.

Ingredients (g/L):

*Adjusted and/or supplemented as required to meet performance criteria.

Directions:

Suspend 18.9g of the medium in 200mL of distilled water, heat for 2-5 minutes. When cooling to 45-50 ℃, pour into sterile petri dishes.

Warning: Prepared medium must be kept dry, can place inverted culture in incubator at 37 ℃ for 1-2 hours.

Procedures:

1. Prepared sample solution according to national standards, SN standard, FDA standards or other methods.

2. Transfer 1mL sample solution into 9ml SCPB broth or alkaline peptone water, enrichment culture for 18-24 hours at 36 ± 1 ℃;

3. Take one ring enrichment broth, streak and inoculate onto Vibrio chromogenic medium, make two plates

4. Enrichment culture for 24±2 hours at 36 ± 1 ℃, the colonies of Vibrio parahaemolyticus are green and have large colonies, Vibrio cholerae are red, other Vibrio are red, blue or colorless and have small colonies, most of other bacteria are inhabited.

5. For undermined colonies, streak them on nutrient agar plates, culture at 36 ± 1 ℃ for 12-16h, select single colony to do a full set of Vibrio parahaemolyticus biochemical tests.

Quality Control:

1. Appearance:

The dehydrate powder medium is homogeneous, having good flowability, yellowish, prepared medium is pale pink to yellow solid.

2. Microbial sensitivity test:

Incubated at 36 ± 1 ℃ 18-24h:

Methods limitations:

The media cannot be directly identified Vibrio cholerae, specificity of Vibrio parahaemolyticus is up to 90%, accuracy is very high, and sometimes may need to do other complementary tests.

Typical features:

The colonies of Vibrio parahaemolyticus are green and have large colonies, Vibrio cholerae are red, other Vibrio are red, blue or colorless and have small colonies

Storage:

The prepared plates can be kept for 2-5 days, avoid direct exposure to light. The powder medium should be placed in a dark, dry place, storage temperature 2-8 ℃, avoid direct exposure to light.

Failure:

Dry powder media which are over the shelf life, caking and color variation cannot be used.

Note:

This medium is only for laboratory use.

Reference:

1. Kobayashi, T., S. Enomoto, R. Sakazaki, and S. Kuwahara. 1963. A new selective medium for pathogenic vibrioses, TCBS(modified Nakanishi's agar). Jpn, J. Bacteriol. 18:387.

2. Nakanishi, Y. 1963. An isolation agar medium for cholerae and enteropathogenic halophilic vibrioses. Modern Media. 9:246

3. Baron, E. J., L. R. Peterson, and S. M. Finegold. 1994. Vibrio and related species, Aeromonas, Plesiomonas, Campylobacter,Helicobacter, and others, p. 429-444. Bailey & Scott's diagnostic microbiology, 9 th ed. Mosby-Year Book, Inc. St. Louis, MO.