The Diversity of Pathotypes and Vaccination Strategies against This Versatile Bacterial Pathogen.

() is a gram-negative bacillus and resident of the normal intestinal microbiota. However, some strains can cause diseases in humans, other mammals and birds ranging from intestinal infections, for example, diarrhea and dysentery, to extraintestinal infections, such as urinary tract infections, respiratory tract infections, meningitis, and sepsis. In terms of morbidity and mortality, pathogenic has a great impact on public health, with an economic cost of several billion dollars annually worldwide. Antibiotics are not usually used as first-line treatment for diarrheal illness caused by and in the case of bloody diarrhea, antibiotics are avoided due to the increased risk of hemolytic uremic syndrome. On the other hand, extraintestinal infections are treated with various antibiotics depending on the site of infection and susceptibility testing. Several alarming papers concerning the rising antibiotic resistance rates in strains have been published. The silent pandemic of multidrug-resistant bacteria including pathogenic that have become more difficult to treat favored prophylactic approaches such as vaccines. This review provides an overview of the pathogenesis of different pathotypes of , the virulence factors involved and updates on the major aspects of vaccine development against different pathotypes.