In light of the rapidity increasing incidence rate of bacterial and fungal infections with multi-resistant pathogens, the metabolic changes associated with host-pathogen interactions offer one of the most promising starting points for developing novel antibiotics. Part one of this comprehensive guide describes the metabolic adaptation of pathogenic microbes in humans, while part two points to routes for the development of novel antibiotics. This is volume six of the book series on drug discovery in infectious diseases by Paul Selzer.