Inhibitory effects of Lactobacillus acidophilus lysates on the cytotoxic activity of shiga-like toxin 2 produced from Escherichia coli O157:H7.
OBJECTIVE
The purpose of this study was to characterize the degree to which four cell lysates obtained from Lactobacillus acidophilus strains affected the cytotoxic activity of Escherichia coli O157:H7 in vitro and in vivo.


RESULTS
In a cytotoxic inhibition test that used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and toxin-binding ELISA assays, the activity of shiga-like toxin 2 (Stx-2) was inhibited profoundly by the cell lysates (10 mg ml(-1)) from two strains of L. acidophilus A4 and 30SC (>85% of survival rates compared with the control) among the five strains tested. In particular, a significant decline in the virulence level of E. coli O157:H7, under the presence of the cell lysates of L. acidophilus A4, was observed by killing assay of Caenorhabditis elegans in vivo model.


CONCLUSIONS
According to our results, L. acidophilus strains might be capable of attenuating the virulence of Stx-2 produced from E. coli O157:H7.


CONCLUSIONS
The cell lysates of L. acidophilus can be applied to a variety of foods, and can be used as adjuncts for the inhibition of Stx-2-mediated cytotoxicity.
Kim
Y
Y
Division of Food Science, Korea University, Seoul, Korea.
Han
K-S
KS
Imm
J-Y
JY
Oh
S
S
You
S
S
Park
S
S
Kim
S-H
SH
D000818:Animals; D001419:Bacteria; D017173:Caenorhabditis elegans / Q000187:drug effects; D002457:Cell Extracts / Q000494:pharmacology*; D002522:Chlorocebus aethiops; D019453:Escherichia coli O157 / Q000472:pathogenicity*; D007779:Lactobacillus acidophilus / Q000502:physiology*; D022641:Shiga Toxin 2 / Q000037:antagonists & inhibitors* / Q000633:toxicity; D014709:Vero Cells; D000095983:Bacterial Lysates
D002457:Cell Extracts; D022641:Shiga Toxin 2; C030259:Broncho-Vaxom; D000095983:Bacterial Lysates