Which of the following characteristics is most associated with Campylobacter jejuni among members of the bacterial world?

• A. It is a curved, Gram-negative rod that grows best at 42°C.
• B. It is an obligate anaerobe that produces endospores.
• C. It is a Gram-positive cocci that forms clusters.
• D. It is a straight, Gram-negative rod that ferments lactose.

Answer: (A)

Verified step by step guidance

1. Step 1: Identify the key characteristics of Campylobacter jejuni from microbiology knowledge. Campylobacter jejuni is known for its distinctive shape, Gram stain reaction, and optimal growth conditions.
2. Step 2: Recall that Campylobacter jejuni is a curved (comma-shaped) Gram-negative rod, which differentiates it from straight rods or cocci.
3. Step 3: Note that Campylobacter jejuni grows best at a higher temperature, specifically around 42°C, which is unusual compared to many other bacteria that prefer 37°C.
4. Step 4: Compare the options given: it is not an obligate anaerobe that produces endospores (this describes some Clostridium species), nor is it a Gram-positive cocci forming clusters (typical of Staphylococcus), nor a straight Gram-negative rod that ferments lactose (typical of some Enterobacteriaceae).
5. Step 5: Conclude that the characteristic most associated with Campylobacter jejuni is that it is a curved, Gram-negative rod that grows best at 42°C.