During a Shigella outbreak linked to a potato salad, which intestinal cells are primarily responsible for uptake of the bacteria?

During a Shigella outbreak linked to a potato salad, which intestinal cells are primarily responsible for uptake of the bacteria?

• A. Paneth cells
• B. Microfold (M) cells
• C. Endothelial cells
• D. Polymorphonuclear cells

Answer: (B)

The key idea is that Shigella uses a specialized gateway in the gut to cross the intestinal barrier: microfold (M) cells. These cells sit in the follicle-associated epithelium over Peyer’s patches and are built to sample lumenal contents and shuttle them to underlying immune tissue. When Shigella is taken up by an M cell, it is delivered to macrophages in the subepithelial space, where it can be released and then invade neighboring epithelial cells, spreading and triggering a robust inflammatory response that causes the characteristic dysentery. Paneth cells reside in crypts and secrete antimicrobial peptides; endothelial cells line blood vessels and aren’t responsible for luminal uptake; polymorphonuclear cells are effector immune cells involved in inflammation, not the entry route. Thus, M cells are the primary route for uptake of the bacteria.

The key idea is that Shigella uses a specialized gateway in the gut to cross the intestinal barrier: microfold (M) cells. These cells sit in the follicle-associated epithelium over Peyer’s patches and are built to sample lumenal contents and shuttle them to underlying immune tissue. When Shigella is taken up by an M cell, it is delivered to macrophages in the subepithelial space, where it can be released and then invade neighboring epithelial cells, spreading and triggering a robust inflammatory response that causes the characteristic dysentery. Paneth cells reside in crypts and secrete antimicrobial peptides; endothelial cells line blood vessels and aren’t responsible for luminal uptake; polymorphonuclear cells are effector immune cells involved in inflammation, not the entry route. Thus, M cells are the primary route for uptake of the bacteria.