Pm. Zadik et al., USE OF TELLURITE FOR THE SELECTION OF VEROCYTOTOXIGENIC ESCHERICHIA-COLI O157, Journal of Medical Microbiology, 39(2), 1993, pp. 155-158
Potassium tellurite was assessed for the selection of verocytotoxigeni
c (VT+) Escherichia coli O157. MICs were higher for VT+ E. coli O157 t
han for other strains of E. coli and for Aeromonas spp. MacConkey medi
um containing sorbitol, tellurite and cefixime (TC-SMAC) permitted the
growth of VT+ E. coli O157 and Shigella sonnei but partially or compl
etely inhibited the growth of 67 % of other strains of E. coli and all
or most strains of other sorbitol-non-fermenting species tested. Of 3
91 rectal swabs from cattle screened on TC-SMAC medium, 26 yielded iso
lates of VT+ E. coli O157 whereas sorbitol-MacConkey medium with cefix
ime and rhamnose yielded only nine isolates. Inclusion of potassium te
llurite in sorbitol-MacConkey agar markedly increased the rate of isol
ation of VT+ E. coli O157 from cattle rectal swabs and may do so for o
ther types of specimen.