Neisseria infection is characteristic of deficiency of:

Ans. D. C5* The best-documented genetic association with meningococcal disease is complement deficiency, chiefly of the terminal complement components (C5-9), properdin, or factor D; such a deficiency increases the risk of disease by up to 600- fold and may result in recurrent attacks.* Complement components are believed to be important for the bactericidal activity of serum, which is considered the principal mechanism of immunity against invasive meningococcal disease.