Tetrathionate Broth Base A.P.H.A

Product information

A selective enrichment broth for the growth of Salmonella typhi and other Salmonella spp. from faeces, foods etc. It conforms to the formulation recommended by the American Public Health Association for use in the examination of dairy products and foods for salmonellae. Organisms which reduce tetrathionate, such as salmonellae, proliferate in the medium, whilst most enteric organisms are inhibited.

Certain members of the Proteus group will also reduce tetrathionate thereby impairing the performance of the medium in some cases. To overcome this, Novobiocin may be added to the medium at a level of 40 microgram/ml before addition of the iodine. Gram-positive organisms are inhibited by the inclusion of bile salts.