All of the following are true regarding the virulence factors of Neisseria gonorrhoeae EXCEPT:

## Virulence Factors of Neisseria gonorrhoeae ### Key Virulence Mechanisms **Key Point:** N. gonorrhoeae possesses multiple virulence factors that facilitate mucosal colonization, evasion of immunity, and tissue invasion — but the capsule is NOT the primary virulence determinant in gonorrhoeae. | Virulence Factor | Function | Clinical Significance | |---|---|---| | **Pili (fimbriae)** | Attachment to non-ciliated columnar epithelium | Essential for initial colonization; phase-variable | | **Lipopolysaccharide (LPS)** | Endotoxin; triggers IL-8, TNF-α, complement activation | Causes local inflammation, tissue damage, urethritis | | **IgA Protease** | Cleaves secretory IgA at hinge region | Disarms mucosal immunity; allows persistence | | **Opacity proteins (Opa/Opc)** | Serum resistance; complement evasion | Facilitates disseminated infection | | **Capsule** | Poorly immunogenic polysaccharide | Present but NOT the primary virulence factor | ### Why Capsule Is NOT the Answer **High-Yield:** The capsule of N. gonorrhoeae is **poorly immunogenic** and plays a minor role in virulence. In contrast, **N. meningitidis** possesses a highly immunogenic polysaccharide capsule that is the primary virulence factor and target of vaccines. This is a classic **trap question** — students often conflate the two Neisseria species. **Clinical Pearl:** The capsule of N. meningitidis (serogroups A, B, C, W, Y) is essential for meningitis pathogenesis and is the basis for meningococcal conjugate vaccines. N. gonorrhoeae does not cause meningitis via capsule-mediated invasion. ### Correct Virulence Factors in Gonorrhoeae 1. **Pili** — phase-variable; allow twitching motility and attachment 2. **LPS endotoxin** — triggers robust inflammatory cascade; responsible for urethritis and cervicitis 3. **IgA protease** — cleaves IgA1 at the hinge; unique among pathogens 4. **Opa/Opc proteins** — confer serum resistance; enable disseminated gonococcal infection (DGI) **Mnemonic:** **PILO** — **P**ili, **I**gA protease, **L**PS, **O**pa proteins = virulence factors of gonorrhoeae. [cite:Jawetz, Melnick & Adelberg's Medical Microbiology 28e Ch 18]