The most frequent bacterial agent causing nongranulomatous uveitis is:
**Core Concept**
Nongranulomatous uveitis is an inflammatory condition of the eye characterized by the infiltration of inflammatory cells into the uveal tract, which includes the iris, ciliary body, and choroid. The etiology of nongranulomatous uveitis can be infectious, autoimmune, or idiopathic.
**Why the Correct Answer is Right**
The most frequent bacterial agent causing nongranulomatous uveitis is **Staphylococcus aureus**. This bacterium can cause endophthalmitis, a severe inflammatory condition of the eye that can result from intraocular surgery, trauma, or injection of exogenous material into the eye. The pathogenesis of endophthalmitis involves the invasion of the intraocular tissues by **Staphylococcus aureus**, leading to the release of pro-inflammatory mediators and the activation of the immune response.
**Why Each Wrong Option is Incorrect**
* **Option B:** While **Pseudomonas aeruginosa** can cause opportunistic infections, it is not the most frequent bacterial agent causing nongranulomatous uveitis.
* **Option C:** **Neisseria gonorrhoeae** can cause gonococcal conjunctivitis, but it is not typically associated with nongranulomatous uveitis.
**Clinical Pearl / High-Yield Fact**
When managing patients with nongranulomatous uveitis, it is essential to consider the possibility of an infectious etiology, particularly **Staphylococcus aureus**, and to obtain cultures and perform diagnostic tests as indicated.
**Correct Answer:** C. Staphylococcus aureus