Human health is constantly being threatened by bacterial pathogens. Foodborne pathogens are responsible for many health crisis and economic losses worldwide. Diarrheal diseases are the second leading cause of childhood mortality worldwide, and also constitute a severe health threat to adults. Most of the foodborne diseases can be prevented through sanitation. However, rapid pathogen evolution, antibiotic resistance and globalization, lead to the quick emergence or reemergence of enteric pathogens both in the developing and the developed world. Moreover, political and economic instability enhances the chances of a bioterrorism attack. Bacterial, virus, or toxins are all considered biological threat agents, and have been previously employed in attacks. Bacterial pathogens share several virulence strategies amongst themselves. They encode toxins that either kill or change signal transduction in mammalian cells. They also employ specialized secretion systems, “molecular syringes”, which inject bacterial proteins called “effectors” that hijack host cell function. These virulence traits tend to be carried in mobile elements that can be quickly transferred between bacteria, leading to the rapid evolution of novel pathovars. Understanding bacterial pathogenic strategies is crucial to prevent or develop new treatments to infectious diseases.