C. elegans as a Model for EPEC Infection

摘要

We have succeeded in establishing C. elegans as a small animal model of EPEC infection. With DARPA support we have demonstrated that EPEC bacteria kill nematodes faster than laboratory control strain MGI655 in the simple kill assay. As predicted, by fluorescent microscopy using bacteria labeled with green fluorescent protein (GEP), EPEC are found in greater numbers in the nematode gut compared to the control strain. EPEC bacteria colonize, and persist within the gut at least to forty-eight hours post-infection, and recent clinical isolates exhibited more robust colonization than the prototypical EPEC strain E2348/69. We found that neither the type III secretion system nor the type IV bundle-forming pilus (BEP) were necessary for colonization. Our most significant finding was that the global regulator Ler is necessary for EPEC to colonize the C. elegans gut. These findings resulted in a report to be published in the January 2006 issue of the ASM journal Infection and Immunity; the page proofs are included as an addendum. We envision the C. elegans model of infection to he useful in identifying potential chemotherapeutic agents against EPEC disease, as well as diseases caused by related gram-negative bacteria, and studying host-microbe interactions, namely attachment, colonization and persistence.