Enteropathogenic E. coli (EPEC) is a major cause of infantile diarrhea. The hallmark 'attaching and effacing' (A/E) lesion on intestinal epithelium is mediated by the bacterial outer membrane protein intimin, which binds to a receptor translocated into the host cell by the Type III secretion system. What is this receptor called?

• A Caspase-1
• B Tir (Translocated intimin receptor) ✓
• C Integrin α5β1
• D E-cadherin

Explanation

EPEC uses a Type III secretion system to inject Tir into the host enterocyte membrane, where it serves as the receptor for the bacterial outer membrane adhesin intimin, producing the characteristic attaching and effacing lesion. EHEC also uses Tir. Integrin and E-cadherin are unrelated. Caspase-1 is an inflammasome component.

Reference: Jawetz, Melnick, and Adelberg's Medical Microbiology, 28th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.