For the detection or recovery of mycoplasmata, which statement is true?

• A. Gram stain can be used.
• B. A swab can be used to gently remove material from the nasopharynx.
• C. A transport medium is not needed.
• D. Some species, such as Mycoplasma hominis, can be grown on SP4 agar.

Answer: (D)

Mycoplasmas are cell-wall–deficient bacteria that require specialized conditions to grow, including media rich in sterols (cholesterol). Because they lack a cell wall, they do not stain reliably with Gram stain, so that method isn’t useful for detection or recovery of these organisms. For culture, they also need proper transport and growth media to preserve viability.

The statement that some species, such as Mycoplasma hominis, can be grown on SP4 agar is true because SP4 is a cholesterol-containing medium specifically used to support the growth of mycoplasmas, including M. hominis. This makes it a valid option for detection or recovery.

The other statements don’t fit as well: Gram stain isn’t reliable for mycoplasmas; a transport medium is needed to keep them viable before culture; and while nasopharyngeal sampling can be part of detection, simply using a swab from the nasopharynx doesn’t address the specialized culture requirements these organisms have.