2.3. EHEC
The production of enterohemolysin was detected
using tryptic soy agar base with 5% of washed sheep
erythrocytes and supplemented with 10 mM CaCl 2. The
blood agar plates were examined after 4 and 24 h
incubation at 37 1C. Hemolysis on the washed blood
agar plates after 24 h but not after 4 h was considered to
be enterohemolysin (Beutin et al., 1995). Tests of
hemolysis induction were made by successive passages
on culture media supplemented with blood.