Bt vs Bg?

Bacillus thuringiensis (Bt) is a kind of bacteria with a naturally-evolved cocktail of toxic proteins that kill insects very efficiently, and supposedly very specifically - they are not supposed to hurt other organisms, like humans for instance (and hence they are very widely used on food crops, even organically certified ones). Some studies, however, have documented toxicity of Bt in other kinds of animals, including fishes and snails. My student Lanie Bradford at GSW has now killed Biomphalaria glabrata (Bg) snails using a commercial formulation of Bt (Dipel). Lanie is now preparing to do a set of experiments to establish the dose-response relationship using Dipel incorporated into snail chow. In insects and nematodes, at least some of the Bt toxins work by causing leaky gut syndrome, allowing normal gut bacteria to invade body tissues causing death by septicemia. Does this happen in snails too? A small dose of Bt toxin might be useful for helping bacterially-delivered dsRNA get into the body and trigger a systemic RNAi response.