Todd Hewitt broth with gentamicin and nalidixic acid is used for the selective enrichment of group B streptococci (Streptococcus agalactiae).

• Do not open until ready to use
• Medium is highly nutritious due to its content of peptones, dextrose and salts
• Store tubes in the dark at 2 to 8 °C

Selective enrichment broths include the advantages of both enrichment and selection by providing conditions conducive to the growth of group B streptococci while inhibiting the growth of contaminants.