HS MEDIUM

Anaerobic bacteria are widespread in soil, marshes, lake and river sediments, oceans, sewage, foods and animals. In humans, anaerobic bacteria normally are prevalent in the oral cavity around the teeth, in the gastrointestinal tract, especially in the colon. Most of these anaerobic habitats have both a low oxygen tension and reduced Eh, resulting from the metabolic activity of microorganisms that consume oxygen through respiration. If the oxygen is not replaced, anaerobic conditions are maintained in the environment. The media used for recovering anaerobes from specimen should include non-selective, selective and enrichment types.
HS Medium was described by Bonnel and Raby for use in sterility testing. It is similar to Fluid Thioglycollate Medium where sodium hydrosulphite is substituted for sodium thioglycollate, in the latter, nto obtain oxidized and reduced conditions which are appropriate for the growth of aerobes as well as anaerobes. HSmedium can be used for the sterility testing of biological and pharmaceutical products. Bonnel and Raby used HS Medium for control tests on blood products and for isolation of Corynebacterium, Streptococci, Staphylococci, enteric bacilli, Neisseria, Clostridia etc.

for cultivation of aerobic as well as anaerobic bacteria and sterility testing