Abstract:

In order to develop an enrichment broth for the simultaneous growth of Salmonella, Shigellosis and
Staphylococcus, several candidate agents were added to pre-formulated broth to observe their growth speeds. The
optimal performance was obtained with the enrichment broth composed of 15 g of tryptone, 5 g of soya peptone, 2.5 g of
monopotassium phosphate, 2.5 g of glucose, 35 g of sodium chloride, 0.5 g of lithium chloride, 0.1 g of bile salt, 2 g of
mannitol and 0.3 g of potassium tellurite in 1000 mL of distilled water. Results showed that Salmonella, Shigellosis and
Staphylococcus aureus could concurrently enrich in this broth and the concentration of bacteria could increased from
103 CFU/mL to 107 CFU/mL during 18 h. The growth of non-target bacteria was suppressed in this broth. Therefore, it may
be a promising broth for simultaneous detection of the three pathogens in a single platform.

Key words: selective enrichment, Salmonella, Shigellosis, Staphylococcus aureus