Food poisoning – gram-positive etiologies Which of the following listed groups includes gram-positive bacteria that are established causes of food poisoning in humans?

Introduction / Context:
Food poisoning may be toxin-mediated or due to invasive infection. Several gram-positive bacteria, notably Clostridium species and Staphylococcus aureus, produce enterotoxins leading to characteristic syndromes.

Given Data / Assumptions:

• We seek a gram-positive group with known foodborne disease potential.
• Options include diverse taxa with different cell wall features and habitats.

Concept / Approach:

Clostridia (e.g., Clostridium botulinum, C. perfringens) are gram-positive, spore-forming anaerobes producing powerful toxins causing botulism and toxin-mediated gastroenteritis. Pseudomonas is gram-negative and not a classic food poisoning agent. Mycoplasmas lack peptidoglycan and are not typical foodborne pathogens.

Step-by-Step Solution:

Verification / Alternative check:

Epidemiology reports and public health advisories consistently implicate Clostridium spp. in outbreaks linked to improperly canned foods or temperature-abused meats and gravies.

Why Other Options Are Wrong:

• Mycoplasmas: respiratory/urogenital pathogens; not food poisoning.
• Pseudomonas: gram-negative opportunists; spoilage, not classic acute food poisoning.
• All/None: inconsistent with established roles.

Common Pitfalls:

• Confusing spoilage organisms with toxin-mediated food poisoning agents.

Final Answer:

Clostridia