Which of the following is a characteristic of Rickettsia?

Rickettsia are obligate intracellular bacteria, meaning they require a host cell to survive and replicate. One of their defining characteristics is their reliance on insect vectors for transmission. They typically infect humans and other hosts through bites from infected ticks, fleas, and lice. This mode of transmission highlights their adaptation to living within the biological systems of these arthropod hosts before they can cause disease in other organisms.

The other options do not align with the known characteristics of Rickettsia. They do not survive for extended periods outside of a host, are not primarily found in soil, and are not responsible for common colds, which are caused by viruses, not bacteria. Consequently, recognizing their vector-borne nature is crucial in understanding their epidemiology and the diseases they cause.