EZ-CHROM* E. coli O157 is a chromogenic media for the isolation and differentiation of E. coli O157 in food / clinical samples. It is available as prepared plated media in packs of 20 or in 5L Packs (sufficient base powder & supplement to make 5 liters of Agar) of dehydrated powder media.
The general food and water standards limits are usually zero to single figure E.coli cfu per gram and thus it is important to detect and enumerate them accurately. With Z-CHROM E.coli, colonies of E.coli develop with an intense blue color - thus making detection and enumeration of this important hygiene indicator as simple as possible.
The conventional medium for detection of E. coli O157, Sorbitol MacConkey Agar, has poor specificity and therefore creates many false positives (Proteus, E. hermanii, etc.). Sorbitol MacConkey Agar is also difficult to read since the E. coli O157 produces colorless colonies among red colonies.
EZ-CHROM E. coli O157 is a chromogenic medium with easier detection of E. coli O157. EZ-CHROM E. coli O157 is 98% sensitive for E. coli O157. E. coli O157 will produce mauve colonies, all other bacteria will appear as steel blue, colorless or red colonies.
*EZ-CHROM plates are a Colorex™ product, EZ-CHROM powder is a CHROMagar™ product