Infectious diseases have plagued humanity throughout history and still represent a major threat for human beings. Driven by the continuous and serious demand for novel therapeutic strategies, the research on the interactions of human pathogens and their virulence factors with the host defense system has been elaborated predominantly using mammalian models such as mice, rats, and rabbits, which provide powerful experimental systems to reproduce human infection. Apart from ethical concerns associated with the exploitation of mammalian host models, the high overall costs for large numbers of individuals, logistic problems, and complex cross talk between the adaptive and the innate immune systems argue for the exploration of alternative host models (Mylonakis, Casadevall, and Ausubel 2007).