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Characterization of Sarcocystis fayeri's actin-depolymerizing factor as a toxin that causes diarrhea
Daisuke Irikura1, Morihiro Saito2, Yoshiko Sugita-Konishi3
1HORIBA Ltd., 2 Miyanohigasi, Kisshoin, Minami-ku, Kyoto, 601-8510, Japan.
Genes to Cells : Devoted to Molecular & Cellular Mechanisms
|August 5, 2017
Summary
A 15-kDa protein from Sarcocystis fayeri, an parasite found in horsemeat, causes diarrhea by acting as an actin-depolymerizing factor (ADF). This protein also triggers cytotoxic substance release, contributing to food poisoning.
Area of Science:
- Parasitology
- Foodborne Illness
- Molecular Biology
Background:
- Raw horsemeat can cause food poisoning, often with diarrhea.
- Sarcocystis fayeri is a parasite found in horsemeat that has been linked to these symptoms.
Purpose of the Study:
- To identify and characterize the diarrhea-inducing protein from Sarcocystis fayeri.
- To investigate the mechanism of action of this protein.
Main Methods:
- Isolation and purification of a 15-kDa protein from Sarcocystis fayeri cysts.
- Cloning the cDNA of the 15-kDa protein using nested polymerase chain reaction.
- Assessing the protein's effect on actin polymerization and its biological activity in vitro and in vivo.
Main Results:
- The 15-kDa protein was identified as an actin-depolymerizing factor (ADF) with homology to known ADF proteins.
- The recombinant protein induced fluid accumulation in the ileum, causing diarrhea.
- The protein also stimulated macrophages to release cytotoxic substances, like tumor necrosis factor-α.
Conclusions:
- The 15-kDa protein of Sarcocystis fayeri belongs to the ADF/cofilin family and is responsible for diarrhea.
- This protein may induce cytotoxic substances, contributing to parasite-instigated food poisoning.
- Further research is needed to fully elucidate the enterotoxic mechanisms involved.
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