A patient presented with trismus and opisthotonus. The probable causative organism is
**Core Concept**
The clinical presentation of trismus (lockjaw) and opisthotonus (a state of hyperextension and spastic rigidity) suggests a condition affecting the nervous system, specifically tetanus. This condition is caused by a neurotoxin produced by a bacterium.
**Why the Correct Answer is Right**
Tetanus is caused by the bacterium *Clostridium tetani*, which produces tetanospasmin, a potent neurotoxin. This toxin affects the release of neurotransmitters, leading to muscle spasms and rigidity. The symptoms presented, such as trismus and opisthotonus, are classic for tetanus infection.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because, although it could be a choice, the specific details are not provided to assess its validity.
**Option B:** Incorrect for the same reason as Option A, lacking detail to confirm its correctness.
**Option C:** Similarly, without specifics, this option cannot be considered accurate.
**Option D:** Also incorrect due to the absence of details to support its claim.
**Clinical Pearl / High-Yield Fact**
Tetanus infection is preventable through vaccination, and its diagnosis is primarily clinical, based on the presence of characteristic symptoms like trismus and opisthotonus. Prompt recognition and treatment are crucial to manage the condition effectively.
**Correct Answer:** D. Clostridium tetani.