**Question:** Culture media for Pseudomonas is: September 2004

**Core Concept:**
Pseudomonas is a group of gram-negative, aerobic, rod-shaped, and non-spore-forming bacteria commonly found in soil and water environments. Culture media play a crucial role in identifying and isolating specific microorganisms from clinical samples, including Pseudomonas species.

**Why the Correct Answer is Right:**
The correct answer refers to the year when the "Cetrimide agar" was introduced as a culture medium for the isolation and differentiation of Pseudomonas species. This medium is selective and differential for the growth of Pseudomonas, allowing for better identification and differentiation from other bacteria.

**Why Each Wrong Option is Incorrect:**
A. "MacConkey agar" is a culture medium primarily used for the differentiation of lactose-fermenting and non-lactose-fermenting bacteria, but not specifically for Pseudomonas isolation and identification.
B. "Chocolate agar" is used for the isolation and identification of anaerobic and facultatively anaerobic bacteria, not Pseudomonas.
C. "Xylose lysine desoxycholate agar" is a selective medium for the isolation of enterobacteriaceae, particularly Salmonella, Shigella, and Escherichia coli. It is not suitable for Pseudomonas isolation.
D. "Cetrimide agar" is the correct answer mentioned above, introduced in 2004.

**Clinical Pearl:**
In clinical microbiology, it is essential to use appropriate culture media to isolate, identify, and differentiate specific bacterial species. Choosing the right culture medium is crucial for accurate diagnosis and appropriate treatment planning. Always consult the latest microbiological guidelines and consider the specific properties of the target microorganism when selecting the appropriate culture medium.