Question

\\(\text{le}^\text{b}\\) antigen has receptors for:

norovirus
h. pylori
rotavirus
e. coli

Explanation:

Identify the core question

The question asks which pathogen uses the \(Le^b\) (Lewis b) antigen as a receptor.

Analyze the biological role of Lewis antigens

Using the Lewis Blood Group knowledge point
The \(Le^b\) antigen is a fucosylated oligosaccharide expressed on epithelial cells and in secretions. It serves as a cell-surface receptor for certain mucosal pathogens.

Match the antigen to the specific pathogen

The bacterium Helicobacter pylori (\(H. pylori\)) expresses an outer membrane protein called BabA (Blood group antigen-binding adhesin). BabA specifically binds to the \(Le^b\) antigen on gastric epithelial cells, facilitating colonization of the stomach lining.

Evaluate the other options

• Norovirus: Primarily binds to histo-blood group antigens (HBGAs) including \(Le^a\), \(Le^b\), and H type 1, but is not the classic textbook association for \(Le^b\) receptors in standard immunohematology curricula.
• Rotavirus: Binds to sialic acid or other cell surface carbohydrates, not specifically characterized by \(Le^b\) binding.
• E. coli: Uses various fimbriae to bind mannose or other glycolipids, not specifically \(Le^b\).

Therefore, \(H. pylori\) is the primary and correct answer.

Answer:

• Norovirus
• H. pylori (Correct answer)
• Rotavirus
• E. coli