SELECTIVE ISOLATION MEDIUM FOR ENTEROHEMORRHAGIC ESCHERICHIA COLI O157, AND ISOLATION

PROBLEM TO BE SOLVED: To obtain the subject medium facilitating the preparation at the time of use, obtained at a low cost compared to a conventional medium and excellent in selectivity and differentiating properties by including a specific selective agent and a specified differentiating agent. SOLUTION: This selective isolation medium contains (A) a selective agent not inhibiting the growth of Escherichia coli O157 and inhibiting the growth of enteric gram-negative bacteria mainly belonging to the genus Proteus, the genus Klebsiella and the genus Salmonella, except the Escherichia coli, and (B) a differentiating agent comprising (i) an enzyme substrate, preferably 5- bromo-4-chloro-3-indoxyl-β-D-galactopyranoside, (ii) a fluorescent substrate, preferably 4-methylumbelliferyl-β-D-glucuronide, (iii) a sugar-alcohol degraded by the Escherichia coli except the O157 and (iv) saccharides of disaccharides degraded by the enteric gram-negative bacteria except the Escherichia coli. The component A preferably comprises an antibiotic such as novobiocin, a tellurous acid salt and a lauryl sulfate salt.