RAPID'sakazakii is a selective chromogenic medium used for isolation and detection of Cronobacter spp. (formerly classified as Enterobacter sakazakii). The most common source of Cronobacter spp. contamination is powdered infant formula.

The principle of the medium is based on detection of a specific enzymatic activity common to all species of Cronobacter. Hydrolysis of the chromogenic substrate 5-bromo-4-chloro-3-indol a-D-glucopyranoside leads to the formation of typical turquoise colored colonies. The medium includes compounds carefully selected to promote the growth of Cronobacter spp. while suppressing interfering flora, giving the medium increased selectivity. Competing bacteria, if not completely inhibited, can form light purple or gray colonies.

Simple and Rapid Protocol
RAPID'sakazakii is formulated for use in standard methods (for example, ISO 22964 reference method). The medium can also be used with a shortened protocol to test 'clean' samples with a low level of contamination, such as powdered infant formula. The short protocol is used to detect Cronobacter spp. in 24 hr after an 18 hr enrichment in buffered peptone water, eliminating the need for selective enrichment.