METHOD AND CULTURE MEDIUM FOR IDENTIFICATION OF SALMONELLAE

摘要

The culture medium and method for distinguishing bacteria of Salmonella spp. from other gram-negative bacteria, especially those belonging to the family Enterobacteriaceae, is based on the ability of salmonellae to utilize melibiose, mannitol, and sorbitol into acids. This property is made use of together with a chromogenic substrate used for identifying beta -galactosidase. Other bacteria of the family Enterobacteriaceae, most of which are beta -galactosidase-positive, appear as brown, blue, or green colonies, depending on the chromogenic substrate used. Apart from Salmonella spp., other beta -galactosidase-negative bacteria, such as Proteus spp., appear as colorless colonies. Salmonellae can be identified directly on the culture medium after incubation, on the basis of their characteristic bright red color.