Cellular infiltrate seen in late pseudomonas infection is formed mainly by ?
**Core Concept**
Pseudomonas aeruginosa is a gram-negative bacterium that can cause severe infections, particularly in immunocompromised individuals. The bacterium can lead to a characteristic cellular infiltrate in the lungs, skin, or other tissues as the infection progresses.
**Why the Correct Answer is Right**
In late pseudomonas infection, a significant cellular infiltrate is formed mainly by **neutrophils**. This is due to the production of pro-inflammatory cytokines, such as TNF-alpha and IL-1 beta, which attract and activate neutrophils to the site of infection. Neutrophils play a crucial role in eliminating the bacteria through phagocytosis and the release of antimicrobial peptides. The influx of neutrophils also leads to tissue damage and the release of elastase, which can contribute to the pathogenesis of pseudomonas infection.
**Why Each Wrong Option is Incorrect**
* **Option A:** While macrophages do play a role in the immune response to pseudomonas, they are not the primary cell type responsible for the cellular infiltrate in late infection.
* **Option B:** Lymphocytes, such as T cells and B cells, are involved in the adaptive immune response to pseudomonas, but they are not the main component of the cellular infiltrate in late infection.
* **Option D:** Eosinophils are typically associated with allergic reactions and parasitic infections, and are not a primary component of the cellular infiltrate in pseudomonas infection.
**Clinical Pearl / High-Yield Fact**
It's essential to recognize the characteristic cellular infiltrate in pseudomonas infection, as it can help guide the diagnosis and treatment of this condition. In particular, the presence of a significant neutrophilic infiltrate in a patient with a suspected pseudomonas infection should prompt a search for underlying immunocompromised states or other risk factors.
**Correct Answer: C. Neutrophils.**