This book covers the wide set of well-regulated virulence factors and defense mechanisms of Pseudomonas aeruginosa focusing on stress responses and the evolution of this opportunistic human pathogen. Pseudomonas aeruginosa is responsible for one out of ten hospital infections.  Additionally, this Gram-negative bacterium is accountable for persistent infections in immunocompromised individuals and the leading cause of chronic lung infections in cystic fibrosis patients. This book provides insight on the metabolic versatility of Pseudomonas aeruginosa and its mechanisms for biofilm formation that make this organism highly efficient  in causing infections.  The book invites the readers to learn more about the intrinsic ability of Pseudomonas aeruginosa to resist a wide variety of antimicrobial agents due to the concerted action of multidrug efflux pumps, antibiotic-degrading enzymes, and the low permeability of bacterial cellular envelopes. Particular focus is put on the evolutionary role of different types of protein-secretion systems in pathogenesis, flagella and their role in chemotaxis and surface sensing, and host-pathogen interactions. This book is a useful introduction to the field for junior scientists interested in the biology and pathogenesis of Pseudomonas aeruginosa. It is also an interesting read for advanced scientists and medical specialists working within this field, providing a broader view of the topic beyond their specific area of specialization.