Which one of the properties listed here as a characteristic of bacterial exotoxins is FALSE?
a. Diffusible, highly toxic, immunogenic protein
b. Marked specificity of action
c. May mimic disease when injected
d. Neutralized by specific IgG antibody
e. Produced only by Gram-positive species.
The correct answer is e. Produced only by Gram-positive species.
Bacterial exotoxins can be produced by both Gram-positive and Gram-negative bacteria. While it is true that many Gram-positive bacteria, such as Clostridium and Staphylococcus, produce exotoxins, some Gram-negative bacteria, like Pseudomonas and Escherichia, also produce exotoxins.