Which virulence factor of Neisseria gonorrhoeae undergoes antigenic variation through gene conversion of silent pilin cassettes, allowing the organism to evade antibodies and reinfect the same host?
- A Lipooligosaccharide
- B IgA protease
- C Type IV pili ✓
- D Porin protein B
Correct answer: C. Type IV pili
Explanation
Gonococcal type IV pili are encoded by one expressed pilE gene plus multiple silent pilS cassettes; recombination into pilE generates new pilin variants, explaining repeated gonorrhoea despite prior infection. IgA protease cleaves secretory IgA but is not the classically tested antigenically varying structure. LOS varies sialylation state but not by cassette gene conversion.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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