A patient with sulphur granules discharging from sinus, suggestive of infection with:
**Core Concept**
The question is testing the student's knowledge of the clinical presentation of chronic granulomatous infections, specifically those caused by Actinomyces species. The presence of sulphur granules in a sinus discharge is a characteristic feature of these infections.
**Why the Correct Answer is Right**
The sulphur granules are actually colonies of Actinomyces bacteria, which are anaerobic, Gram-positive rods that can cause chronic infections in humans. The granules are formed due to the aggregation of bacterial cells in a protective matrix, which gives them a characteristic yellowish appearance. The infection typically occurs in the oral cavity, particularly in people with dental caries or periodontal disease, and can spread to the sinuses or other parts of the body.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not match the clinical presentation of Actinomyces infection. While dental infections can cause sinusitis, the presence of sulphur granules is a specific indicator of Actinomyces infection.
**Option B:** This option is incorrect because it refers to a different type of infection altogether. Aspergillosis is a fungal infection that can cause sinusitis, but it does not typically present with sulphur granules.
**Option C:** This option is incorrect because it is a type of bacterial infection that does not typically cause chronic granulomatous infections. E. coli is a common cause of urinary tract infections and other acute bacterial infections, but it is not associated with sulphur granules.
**Option D:** This option is incorrect because it refers to a different type of infection altogether. Histoplasmosis is a fungal infection that can cause chronic granulomatous infections, but it does not typically present with sulphur granules.
**Clinical Pearl / High-Yield Fact**
The presence of sulphur granules in a sinus discharge is a classic indicator of Actinomyces infection, which requires prompt treatment to prevent spread to other parts of the body.
**Correct Answer:** C. Actinomyces israelii.