Prepared Plated Media PPM

TCBS AGAR

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Catalog Number : 905

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Description

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TCBS AGAR is a selective medium widely used to isolate and cultivate practically all bacteria of the genus Vibrio, including V. cholerae and V. alginolyticus, pathogenic to humans causing cholera, choleral diarrhea or food poisoning from contaminated foods and from stool specimens. The last 2 conditions especially can be caused by ingesting raw or partially processed fi sh or seafood containing Vibrio parahemolyticus. The only Vibrio that does not grow in TCBS is V. hollisae.The Meat and Casein peptones provide nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group. Sodium citrate, Sodium thiosulfate and Ox bile are the selective agents, inhibiting the Gram-positive bacteria. Sodium thiosulfate provides sulphur, and Ferric citrate is the indicator for H2S production. Sucrose is the carbohydrate energy source. Bromothymol blue and Thymol blue are pH indicators. Sodium chloride promotes growth (Vibrio grows well in salty media). Bacteriological agar is the solidifying agent. The alkaline pH of the medium enhances the recovery of V. cholerae.

The suspect material (feces, vomit, rectal swabs, fi sh, and other food) is heavily inoculated on the surface of the plate, incubated at 35 ± 2°C for 18 - 24 hours. Sucrose-positive vibrios, such as Vibrio cholerae and Vibrio alginolyticus, are yellow on TCBS. Sucrose-negative ones, such as Vibrio parahaemolyticus and Vibrio vulnifi cus, produce blue-green colonies.

Almost all Vibrio ferment sucrose and yield yellow colonies from the production of acid. Some types of Proteus (fermenters of sucrose) can form yellow colonies similar to those of Vibrio.

MICROBIOLOGICAL TEST
The following results in the were obtained performance of the medium from type cultures after incubation at a temperature of 35 ± 2°C and observed after 18 - 24 hours.