A Case of Co-infection Due to Shigella flexneri Colitis Resulting in Bacillus Septic Shock in an Immunocompetent Patient.

Shigella flexneri (S. flexneri) is a facultatively anaerobic gram-negative bacterium that is a member of Enterobacteriaceae. The bacterium has been known to cause mild symptoms, such as diarrhea, to more severe diseases such as hemorrhagic colitis.