The infectious process of plant by bacteria is not a simple, isolated and fortuitous event. Instead, it requires a vast collection of molecular and cell singularities present in bacteria in order to reach target tissues and ensure successful cell thriving. The bacterium Xanthomonas citri ssp. citri is the etiological agent of citrus canker, this disease affects almost all types of commercial citrus crops. In this chapter we review the main structural and functional bacterial features at phenotypical and genotypical level that are responsible for the symptomatology and disease spread in a susceptible host. Biological features such as: bacterial attachment, antagonism, effector production, quorum sensing regulation and genetic plasticity are the main topics of this review.