Veillonella can be described as which combination of Gram stain and oxygen requirement?

Veillonella can be described as which combination of Gram stain and oxygen requirement?

• A. Gram-positive and aerobic
• B. Gram-positive and anaerobic
• C. Gram-negative and aerobic
• D. Gram-negative and anaerobic

Answer: (D)

Veillonella are Gram-negative cocci that thrive in environments without oxygen. The Gram stain result for these bacteria shows a pink/red color due to their thin peptidoglycan layer and outer membrane, characteristic of Gram-negative organisms. They are obligate anaerobes, meaning they do not tolerate oxygen and do not grow in its presence. So, the description that fits them best is Gram-negative and anaerobic. In the oral cavity, they are commonly found in anaerobic niches like dental plaque, where oxygen is limited. They are not Gram-positive, and they are not aerobic, so descriptions emphasizing those traits don’t apply.

Veillonella are Gram-negative cocci that thrive in environments without oxygen. The Gram stain result for these bacteria shows a pink/red color due to their thin peptidoglycan layer and outer membrane, characteristic of Gram-negative organisms. They are obligate anaerobes, meaning they do not tolerate oxygen and do not grow in its presence. So, the description that fits them best is Gram-negative and anaerobic. In the oral cavity, they are commonly found in anaerobic niches like dental plaque, where oxygen is limited. They are not Gram-positive, and they are not aerobic, so descriptions emphasizing those traits don’t apply.