An organism produces cutaneous disease (malignant pustule or eschar) at the site of inoculation in handlers of animal skins. Most likely organism is:
**Core Concept**
The question is testing the student's knowledge of zoonotic infections, specifically the transmission of disease from animals to humans through direct contact. The organism in question is a bacterium that causes a distinctive cutaneous lesion upon inoculation.
**Why the Correct Answer is Right**
The correct organism is *Bacillus anthracis*, which causes anthrax. This bacterium produces spores that can survive in the environment for long periods and cause infection when inhaled, ingested, or inoculated through the skin. The cutaneous form of anthrax, also known as malignant pustule or eschar, is characterized by a painless, ulcerative lesion that eventually forms a black eschar. This form of the disease occurs when spores enter the body through a cut or scratch in the skin.
**Why Each Wrong Option is Incorrect**
* **Option A:** *Staphylococcus aureus* is a common cause of skin infections, but it does not produce the characteristic cutaneous lesion described in the question.
* **Option B:** *Mycobacterium bovis* causes tuberculosis in cattle, but it does not typically cause cutaneous disease in humans.
* **Option C:** *Pasteurella multocida* is a bacterium that causes disease in animals, but it is not the primary cause of the cutaneous lesion described in the question.
**Clinical Pearl / High-Yield Fact**
When handling animal skins, it's essential to wear protective clothing, including gloves and masks, to prevent exposure to zoonotic pathogens like *Bacillus anthracis*.
**Correct Answer:** C.