The normal chain length distribution of the O antigen is required for the interaction of Shigella flexneri 2a with polarized Caco-2 cells.

Shigella flexneri causes bacillary dysentery in humans. Essential to the establishment of the disease is the invasion of the colonic epithelial cells. Here we investigated the role of the lipopolysaccharide (LPS) O antigen in the ability of S.

Contribution of the lipopolysaccharide to resistance of Shigella flexneri 2a to extreme acidity.

Shigella flexneri is endemic in most underdeveloped countries, causing diarrheal disease and dysentery among young children. In order to reach its target site, the colon, Shigella must overcome the acid environment of the stomach. Shigella is able to persist in this stressful environment and, because of this ability it can initiate infection following the ingestion of very small inocula.

The Salmonella enterica serovar Typhi tsx gene, encoding a nucleoside-specific porin, is essential for prototrophic growth in the absence of nucleosides.

The Salmonella enterica serovar Typhi tsx gene encodes a porin that facilitates the import of nucleosides. When serovar Typhi is grown under anaerobic conditions, Tsx is among the outer membrane proteins whose expression increases dramatically. This increase in expression is due, at least in part, to increased transcription and is dependent on Fnr but not on ArcA.