(AB) Tetrathionate Broth Base, 2 Kilograms

The use of Tetrathionate Broth for the cultivation of Salmonella species was first described by Mueller. Mueller demonstrated that lactose fermenting members of the Enterobacteriaceae were inhibited or killed in the medium while the salmonellae grew almost unrestricted. Shaeffer demonstrated the enrichment properties of the medium, reporting that he obtained four times as many isolates of salmonellae after specimen enrichment in Tetrathionate Broth than found on direct platings. Kauffman modified the formula and reported marked increase in recovery of Salmonella. Tetrathionate Broth Base conforms to the formulation recommended by the American Public Health Association for use in the examination of dairy productss and foods for the presence of salmonellae. Tetrathionate Broth Base is enriched with iodine solution for the selective cultivation of Salmonella species. Bile salts are incorporated in the medium as the selective agent to retard the growth of gram- negative bacilli other than salmonellae, and inhibit gram-positive organisms. Tetrathionate Broth Base with iodine-iodide solution added, is a selective enrichment liquid medium used for the cultivation of Salmonella typhi from feces, urine, foods and other materials of sanitary importance. (Alpha Biosciences # T20-104-2Kg)

Use: Tetrathionate Broth Base with iodine-iodide solution added, is a selective enrichment liquid medium used for the cultivation of Salmonella typhi from feces, urine, foods and other materials of sanitary importance.

Description: The use of Tetrathionate Broth for the cultivation of Salmonella species was first described by Mueller. Mueller demonstrated that lactose fermenting members of the Enterobacteriaceae were inhibited or killed in the medium while the salmonellae grew almost unrestricted. Shaeffer demonstrated the enrichment properties of the medium, reporting that he obtained four times as many isolates of salmonellae after specimen enrichment in Tetrathionate Broth than found on direct platings. Kauffman modified the formula and reported marked increase in recovery of Salmonella. Tetrathionate Broth Base conforms to the formulation recommended by the American Public Health Association for use in the examination of dairy productss and foods for the presence of salmonellae. Tetrathionate Broth Base is enriched with iodine solution for the selective cultivation of Salmonella species. Bile salts are incorporated in the medium as the selective agent to retard the growth of gram- negative bacilli other than salmonellae, and inhibit gram-positive organisms.

Formula* per Liter:

• Casein Digest Peptone.................... 2.5g
• Sodium Thiosulfate ..................... 30.0g
• Peptic Digest of Animal Tissue ...... 2.5g
• Bile Salts ........................................ 1.0g
• Calcium Carbonate ........................ 10.0g

Final pH: 8.4 ± 0.2 at 25.0°C

* Grams per liter may be adj. or formula supplemented to obtain desired performance

Preparation: Mix 46 grams of the medium in a Liter of purified water until evenly dispersed. Heat with repeated stirring to boiling. Cool to 45.0°C before adding 20ml of an iodine-iodide solution (6g iodine + 5g potassium iodide in 20 ml of purified water).

Quality Control Specifications:

1. The powder is homogeneous, free flowing and white.
2. Visually the prepared medium is milky white and opaque.
3. Recovery on MacConkey Agar after enrichment in Tetrathionate Broth for 18-24 hours at 35.0°C.

Organism                                                                               Result

Escherichia coli ATCC 25922                                          Growth Inhibited

Salmonella typhi ATCC 19430                                           Good Growth

Salmonella typhimurium ATCC 14028                               Good Growth

Shigella flexneri ATCC 12022                                          Growth Inhibited

Storage: Store the sealed bottle containing the dehydrated medium at 2 to 30.0°C. Once opened and recapped, place the container in a low humidity environment at the same storage temperature. Protect it from moisture and light. The dehydrated medium should be discarded if it is not free flowing or if the color has changed from the original white color.