Which statement is true about mycoplasmas?

Which statement is true about mycoplasmas?

• A. Resistant to penicillin
• B. Not able to survive extracellularly.
• C. Easily stained using the Gram stain
• D. Grow on routine nonselective culture media

Answer: (A)

Mycoplasmas lack a peptidoglycan-based cell wall. Penicillin and other beta-lactam antibiotics work by disrupting cell wall synthesis, so without a cell wall these drugs have nothing to target, making mycoplasmas resistant to penicillin. That’s why this statement is true. In addition, they don’t stain reliably with Gram stain and they won’t grow on routine nonselective culture media; they require specialized media that includes cholesterol and other nutrients. These features explain why the other statements aren’t correct.

Mycoplasmas lack a peptidoglycan-based cell wall. Penicillin and other beta-lactam antibiotics work by disrupting cell wall synthesis, so without a cell wall these drugs have nothing to target, making mycoplasmas resistant to penicillin. That’s why this statement is true. In addition, they don’t stain reliably with Gram stain and they won’t grow on routine nonselective culture media; they require specialized media that includes cholesterol and other nutrients. These features explain why the other statements aren’t correct.