A patient with conjunctival infection, which lead to corneal perforation, was positive for Gram-negative coccoid appearance on Gram stain. Further investigation showed small translucent colourless organism which is oxidase positive. What could be the most probable causative organism-

**Core Concept**
The underlying principle being tested is the identification of a specific bacterial pathogen based on its Gram stain appearance, oxidase positivity, and clinical presentation. This involves understanding the characteristics of **Neisseria** species, which are known for their Gram-negative coccoid appearance.

**Why the Correct Answer is Right**
The correct answer is likely **Neisseria gonorrhoeae**, given the Gram-negative coccoid appearance on Gram stain and the oxidase-positive result. **Neisseria gonorrhoeae** is a common cause of conjunctivitis, particularly in newborns, and can lead to severe complications such as corneal perforation if left untreated. The bacterium's ability to cause invasive disease is linked to its virulence factors and the host's immune response.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it does not match the description of a Gram-negative coccoid bacterium.
**Option B:** Incorrect as it is not typically associated with conjunctival infections leading to corneal perforation.
**Option C:** Incorrect because, although it can cause eye infections, it does not fit the Gram stain and oxidase-positive criteria provided.

**Clinical Pearl / High-Yield Fact**
It's crucial to remember that **Neisseria gonorrhoeae** can cause severe eye infections, and prompt treatment with antibiotics is essential to prevent complications like corneal perforation.

**Correct Answer:** D. Neisseria gonorrhoeae

✓ Correct Answer: B. Neisseria gonorrhea