Which statement best describes the general microbial status of axenic animals?

Which statement best describes the general microbial status of axenic animals?

• A. They are completely free from all detectable microorganisms.
• B. They harbor a defined mixture of microbes only.
• C. They carry only viruses.
• D. They are identical to barrier-reared animals.

Answer: (A)

Axenic status means germ-free: the animal has no microorganisms present on or in it that can be detected by standard methods. They are raised and kept in sterile conditions, with sterile food, water, and equipment, and handled in a way that prevents any microbial exposure. Because the goal is to prevent any microbial presence, axenic animals are described as completely free from detectable microorganisms, not just from particular types or a defined mix. This differs from barrier-reared or SPF animals, which are protected from contamination but still harbor a normal or defined set of microbes. The other statements describe situations that aren’t germ-free (a defined mix, only viruses) or imply equivalence with barrier-reared status, which isn’t accurate for axenic animals.

Axenic status means germ-free: the animal has no microorganisms present on or in it that can be detected by standard methods. They are raised and kept in sterile conditions, with sterile food, water, and equipment, and handled in a way that prevents any microbial exposure. Because the goal is to prevent any microbial presence, axenic animals are described as completely free from detectable microorganisms, not just from particular types or a defined mix. This differs from barrier-reared or SPF animals, which are protected from contamination but still harbor a normal or defined set of microbes. The other statements describe situations that aren’t germ-free (a defined mix, only viruses) or imply equivalence with barrier-reared status, which isn’t accurate for axenic animals.