Bactericidal activity of a fermented hot-water extract from Stevia rebaudiana Bertoni towards enterohemorrhagic Escherichia coli O157:H7 and other food-borne pathogenic bacteria.
A fermented aqueous extract from Stevia rebaudiana Bertoni showed strong bactericidal activity towards a wide range of food-borne pathogenic bacteria including enterohemorrhagic Escherichia coli O157:H7. The colony-forming ability of the food-borne pathogenic bacteria tested so far was reduced to < 10(-7) when exposed to > or = 40% (v/v) solutions of the fermented extract at 37 C for 2 hr. Secretion of verocytotoxin 1 and 2 by enterohemorrhagic E. coli was also diminished by fermented extract at a concentration of > or = 10% (v/v). In contrast, the fermented extract did not significantly kill Bifidobacteria or Lactobacilli. The active principle(s) of the fermented Stevia extract were bactericidal under acidic conditions.
Tomita
T
T
Faculty of Agriculture, Tohoku University, Sendai, Miyagi, Japan. tomita@biochem.tohoku.ac.jp
Sato
N
N
Arai
T
T
Shiraishi
H
H
Sato
M
M
Takeuchi
M
M
Kamio
Y
Y
D001427:Bacterial Toxins / Q000378:metabolism; D015169:Colony Count, Microbial; D004352:Drug Resistance, Microbial; D004755:Enterobacteriaceae / Q000187:drug effects / Q000254:growth & development; D019453:Escherichia coli O157 / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D005285:Fermentation; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000382:microbiology; D016987:Gram-Positive Rods / Q000187:drug effects / Q000254:growth & development; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010936:Plant Extracts / Q000494:pharmacology*; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development
D001427:Bacterial Toxins; D010936:Plant Extracts; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2