Selenite f broth

Selenite F broth components and application

1. Selenite F Broth Abhishek R. Indurkar 17PBT202 MTech Pharmabiotech

2. Selenite-F Broth Selenite-F Broth was devised by Leifson, who demonstrated that selenite was inhibitory for coliforms and certain other microbial species, such as fecal streptococci, present in fecal specimens, and thus, was beneficial in the recovery of Salmonella species. F in Selenite F Broth is Faeces , because it is mostly used for the isolation of Salmonella and Shigella from faecal specimens.

3. Composition of Selenite F Broth Casein enzymic hydrolysate 5 gm/L Lactose 4 gm/L Sodium phosphate 10 gm/L Sodium hydrogen selenite (NaHSeO 3 ) 4 gm/L pH 7.1 ± 0.2 @ 25°C

4. Principle Casein enzymic hydrolysate provides nitrogenous substances. Lactose is a carbohydrate source. Sodium phosphate maintains a stable pH and also lessens the toxicity of selenite. Sodium selenite inhibits many species of gram-positive and gram-negative bacteria including enterococci and coliforms.

5. Preparation Add 4.0 gm sodium selenite powder to distilled water. Add remaining 19.0 gm powder to above solution and bring volume to 1.0 litre. Gently heat and bring to boiling. Dispense into sterile test tubes, at least of a depth of 5 cm. Sterilize in boiling water bath or at 0 psi pressure at 100°C for 10 minutes. DO NOT AUTOCLAVE. Cool to room temperature prior to use.

6. Quality Control on Selenite F Broth Positive control: Salmonella Typhimurium ATCC® 14028. Good Growth. Negative control: Escherichia coli ATCC® 25922. Inhibited or no growth.

7. Uses Selenite F Broth is used as a selective enrichment for the cultivation of Salmonella spp. It is also used as an enrichment medium for the isolation of some species of Shigella. The broth is also recommended for the transport of strains of Vibrio cholerae , because these organisms can survive 2 to 5 days in Sodium Selenite Broth.

8. Limitations Sodium hydrogen selenite (Sodium biselenite) is very toxic, corrosive agent and causes teratogenicity. Handle with great care. If there is contact with skin, wash immediately with lot of water. Due to nutritional variation, some strains may be encountered that grow poorly or fail to grow on this medium.

9. References E&O Laboratories Ltd- Selenite F Broth (BM0360). HiMedia Laboratories Pvt. Ltd.- Selenite Broth (Selenite F Broth) (Twin Pack) (M052). Mast Diagnostics- Selenite F Broth

10. Thank you