Which two species are the primary spore-forming bacteria of concern that must be controlled to prevent toxin production in processing?

• A. Listeria monocytogenes and Salmonella
• B. Clostridium perfringens and Clostridium botulinum
• C. Staphylococcus aureus and Bacillus cereus
• D. Escherichia coli O157:H7 and Campylobacter

Answer: (B)

Spore-forming bacteria are especially troublesome in processed foods because their spores withstand heat and sanitation, and they can germinate later to produce potent toxins. The two biggest culprits in this regard are Clostridium botulinum and Clostridium perfringens. Both form spores and can generate toxins under favorable conditions, particularly in anaerobic, low-acid environments or with time-temperature abuse. Botulism toxin from Clostridium botulinum is extremely potent, so preventing its formation is a primary safety goal in processing. Clostridium perfringens can produce enterotoxins that cause food poisoning, especially in meats and other cooked foods that aren’t kept hot or cooled quickly enough.

Other options either involve organisms that don’t form spores or produce toxins in a way that isn’t as central to the processing concerns. For example, Listeria and Salmonella are non-spore-formers; Staphylococcus aureus isn’t a spore-former; Bacillus cereus is a spore-former and toxin producer, but the strongest processing emphasis for preventing major toxin production tends to focus on these two Clostridium species.