S. boydii S. dysenteriae S. flexneri S. sonnei Shigella is a genus of bacteria that is Gram negative, facultatively anaerobic, non–spore-forming, nonmotile, rod shaped, and is genetically nested within Escherichia.

[5] Shigella is a leading cause of bacterial diarrhea worldwide, with 80–165 million annual cases (estimated)[6] and 74,000 to 600,000 deaths.

[12] Because they do not interact with the apical surface of epithelial cells — preferring the basolateral side — Shigella species invade the host through the M-cells interspersed in the epithelia of the small intestine.

[17] Shigella uses a type-III secretion system that acts as a biological syringe to translocate toxic effector proteins to the target human cell.

As a result, CaM mistakenly recognizes the bacterial proteins as CaMKII, preventing the normal function of the signaling pathway and blocking ISG expression.

Shiga entered the Tokyo Imperial University School of Medicine in 1892, during which he attended a lecture by Shibasaburo Kitasato.

Shiga was impressed by Kitasato's intellect and confidence, so after graduating, he went to work for him as a research assistant at the Institute for Infectious Diseases.

[22] Shiga studied 32 dysentery patients and used Koch's postulates to successfully isolate and identify the bacterium causing the disease.

He continued to study and characterize the bacterium, identified its methods of (Shiga-) toxin production, and worked to create a vaccine for the disease.