Characteristic infection of nocardia asteroides is?
**Core Concept**
Nocardia asteroides is an aerobic, Gram-positive actinomycete that causes a type of opportunistic infection in humans. It typically affects immunocompromised individuals, such as those with chronic lung disease or HIV/AIDS.
**Why the Correct Answer is Right**
Nocardia asteroides primarily causes pulmonary infections, which can progress to disseminated disease if left untreated. The bacteria enter the lungs through inhalation, where they can cause abscesses and granulomas. The infection is characterized by the formation of characteristic "sulfur granules" in the affected tissues, which are actually aggregates of the bacteria.
**Why Each Wrong Option is Incorrect**
* **Option A:** While Nocardia species can cause skin infections, they are not typically associated with this type of infection.
* **Option B:** Nocardia asteroides is not a type of fungal infection, but rather a bacterial one.
* **Option C:** Nocardia species can cause infections in other parts of the body, such as the brain or kidneys, but pulmonary infection is the most common presentation.
**Clinical Pearl / High-Yield Fact**
Nocardia asteroides is often misdiagnosed as a fungal infection due to its appearance under the microscope, but it can be distinguished by its positive Gram stain and ability to grow on standard bacterial media.
**Correct Answer: D. Pulmonary infection. Pulmonary infection by Nocardia asteroides.**