Beta-glucuronidase activity of Vero cytotoxin-producing strains of Escherichia coli, including serogroup 0157, isolated in the United Kingdom

One hundred and twenty Vero cytotoxin‐producing (VT+) strains of Escherichia coli 0157 (of H type 7 or non‐motile) isolated in the UK, failed to ferment sorbitol after 24 h or to hydrolyse 4‐methylumbelliferyl‐beta‐d‐glucuronide (MUG). This combination of properties was not found in 167 of 169 other E. coli strains, including VT+strains of other serogroups and VT‐strains of serogroup 0157. As the two exceptions were rare VT‐strains of serotype 0157: H7, we conclude that, although biochemical tests can aid the isolation of VT+0157 strains, confirmation of VT production is necessary.