Final answer:
To establish itself as a host, a microbe must go through stages of pathogenesis: exposure, adhesion, invasion, and infection, while evading the immune system. Some microbes, such as viruses, require host cells for cultivation and recognize hosts by attaching to their cell receptors. A successful long-term infection also relies on a close physiological match between the pathogen and the host's system.
To istablish itself a host, a microbe must pathogenesis
Step-by-step explanation:
To establish itself as a host, a microbe must successfully complete several steps known as the stages of pathogenesis. These steps include exposure to the host, adhesion to establish colonization, invasion, and ultimately causing infection. During this process, the microbe must acquire resistance to the host's natural defense processes, which typically work to detect and eliminate foreign cells. Moreover, pathogens must be able to evade or overcome the host's immune system, often through mechanisms of 'stealth pathogenesis,' such as avoiding capture by phagocytic cells or reproducing inside them.
Some pathogens, including viruses and certain bacteria like Rickettsia and Chlamydia, are obligate intracellular pathogens and can only grow inside a host cell. Viral cultivation, for instance, requires a host cell because viruses recognize their host by attaching to specific receptor sites on the host cell's surface. This can involve either forcing the cell to lyse or fusing with the cell membrane to gain entry.
Lastly, the physiological match between the pathogen and the host is crucial for a successful long-term invasion and infection, making the pathogen's compatibility with the host's system an important factor in its ability to establish itself.