The Latin American region has been at the forefront in combating infections caused byEscherichia colistrains in humans, animals, and the environment. The continuous emergence and evolution of pathogenicE. colistrains associated with human and animal infections have demonstrated that (i) groups of related pathogenicE. coliare responsible for most infections caused by this bacterial species; (ii) diverse virulence phenotypes expressed during infection defined each one of these pathogroups; (iii) the geographical distribution of pathogroups in Latin America and the evolution of new isolates was...