Usually associated with raw milk and meat products. Individual isolates are group specific. The protein is essentially a protoxin, is harmless in its natural state, but when cleaved proteolytically in the larval gut, it becomes activated. Toxin binds to the epithelial cell wall, induces pore formation, causes leakage in the cell, and eventually cell lysis. Death of larvae due to starvation Domains specific for binding and toxicity The genes responsible for the Bt toxin are used in plant genetic engineering to make them less susceptible to these insects.
Some Clostridia are opportunistic pathogens.
C. tetani C. botulinum C. perfringens. Again rarely replicates in the human body. Relies on ingestion of large numbers of cells that then sporolate in gastrointestinal tract, producing toxins Large bulk cooked meat where heat penetration is insufficient to kill all cells, and then left at warm temperatures to allow multiplication of cells. Some members Listeria Brocothrix Carnobacterium Description Regular shaped rods Chemoorganotrophic Require complex nutrients Commonly associated with plants, animals, decaying organic matter Listeria Important member. Primarily inhabit soils, but some genera found on skin, plants, milk, cheese.