Which term describes a microorganism in its non-infective state?

The term that describes a microorganism in its non-infective state is spore. Spores represent a dormant and resilient form of certain types of microorganisms, such as bacteria and fungi, that allows them to survive in harsh conditions without causing an infection. When environmental conditions become favorable, these spores can germinate and revert to their active state, potentially leading to infection.

In contrast, bacterium and fungus refer to specific types of microorganisms in their active forms, capable of causing infections under the right circumstances. A virus, while it can also exist in a latent state within a host, does not form spores and requires a living host to replicate and become infective. Therefore, the spore is the correct term that accurately represents a microorganism in its non-infective, dormant state.