J.E. Trempy gratefully acknowledges the invaluable input from her colleague, Dr Philip McFadden and the contributions of numerous undergraduate students including Navarro Shamon Jamerson, Michael Sjevcar, Stan Atkin, Ryan Smith and Jacob McCormick. The authors thank Dr Mahfuzur Sarker and Dr Didier Lereclus for generously providing C. perfringens SM101 and a B. cereus ΔplcR deletion mutant strain that is a derivative of ATCC 14579, respectively. This research was supported by grants from the Dr Harry B. and Ralph H. Levey Philanthropic Fund and the Tartar Foundation. A predoctoral fellowship award from the Department of Homeland Security (DHS) under the DHS Scholarship and Fellowship Program supported J.R. Hutchison, and HHMI (Howard Hughes Medical Institute) and URISC undergraduate summer research fellowships supported C.A. Carlyle.