Which of the following Corynebacterium toxin is similar to that of diphtheria toxin?
**Core Concept**
Corynebacterium diphtheriae produces a potent toxin that causes diphtheria, a serious bacterial infection. The toxin shares structural and functional similarities with other exotoxins produced by Corynebacterium species, including Corynebacterium ulcerans and Corynebacterium pseudotuberculosis.
**Why the Correct Answer is Right**
The toxin produced by Corynebacterium diphtheriae is a zinc-dependent metalloprotease that inhibits protein synthesis by cleaving elongation factor 2. This mechanism is similar to that of other bacterial toxins, such as the exfoliative toxin produced by Staphylococcus aureus. The toxin's structure and function are also similar to those of the toxin produced by Corynebacterium ulcerans, which causes a similar disease.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is a toxin produced by Clostridium perfringens, which causes gas gangrene and food poisoning. While it is a potent toxin, it is not similar to the toxin produced by Corynebacterium diphtheriae.
**Option B:** This option is incorrect because it is a toxin produced by Shigella dysenteriae, which causes dysentery. The toxin's mechanism of action is different from that of the toxin produced by Corynebacterium diphtheriae.
**Option C:** This option is incorrect because it is a toxin produced by Clostridium tetani, which causes tetanus. The toxin's mechanism of action is different from that of the toxin produced by Corynebacterium diphtheriae.
**Clinical Pearl / High-Yield Fact**
The toxin produced by Corynebacterium diphtheriae is highly potent and can cause severe respiratory and cardiac complications. It is essential to diagnose and treat diphtheria promptly to prevent long-term sequelae.
**Correct Answer: C. Pseudomonoexfoliative toxin**