Mucormycosis (caused by Mucor, Rhizopus, Cunninghamella species) characteristically produces angioinvasion. The virulence factor responsible for this affinity for vascular endothelium is:
- A Aflatoxin production causing direct endothelial toxicity
- B GRP78 (glucose-regulated protein 78) expressed on hyperglycaemic/DKA endothelial cells, serving as a receptor for spore surface protein CotH ✓
- C Mannoprotein binding to CD44 on macrophages enabling intracellular survival
- D Production of gliotoxin suppressing neutrophil function and enabling invasion
Explanation
Mucorales spores express spore coat protein homologue (CotH) on their surface, which binds to GRP78 — a glucose-regulated protein overexpressed on the surface of endothelial cells in states of hyperglycaemia, elevated serum iron, and diabetic ketoacidosis (DKA). This interaction directly mediates fungal invasion of vessel walls, causing the characteristic angioinvasion and thrombosis of mucormycosis. This explains the strong clinical association with DKA, poorly controlled diabetes, and iron overload (deferoxamine therapy). Gliotoxin is an Aspergillus virulence factor.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.