Comparison of meningococcus and gonococcus Pathobiology e Similarities. Both diplococci Share about 80% dNA Neither makes exotoxin: both make endotoxin Both are relatively good colonizers Other species colonize mucous membranes and skin and rarely cause disease BIOL 533 Lecture ll
BIOL 533 2 Lecture 11 Comparison of Meningococcus and Gonococcus • Pathobiology • Similarities: – Both diploccocci – Share about 80% DNA – Neither makes exotoxin; both make endotoxin – Both are relatively good colonizers • Other species colonize mucous membranes and skin, and rarely cause disease
Comparison of meningococcus and gonococcus Differences Gonococcus causes gonorrhea Localized inflammation(usually in urethra)and is very rarely fatal Meningococcus causes meningitis and other diseases Systemic and life-threatening disease BIOL 533 Lecture ll
BIOL 533 3 Lecture 11 Comparison of Meningococcus and Gonococcus • Differences: – Gonococcus causes gonorrhea • Localized inflammation (usually in urethra) and is very rarely fatal – Meningococcus causes meningitis and other diseases • Systemic and life-threatening disease
Comparison of meningococcus and gonococcus Why are diseases so different Presence in normal flora 10% healthy people colonized by meningococcus in posterior pharynx Gonococcus not present BIOL 533 Lecture ll
BIOL 533 4 Lecture 11 Comparison of Meningococcus and Gonococcus • Why are diseases so different? • Presence in normal flora – 10% healthy people colonized by meningococcus in posterior pharynx – Gonococcus not present
Comparison of meningococcus and gonococcus Penetration of mucous membranes Mechanism similar for the two organisms Penetrate different mucous membranes columnar epithelial cells Meningococcus---nasopharnyx Gonococcus--fallopian tubes BIOL 533 Lecture ll
BIOL 533 5 Lecture 11 Comparison of Meningococcus and Gonococcus • Penetration of mucous membranes – Mechanism similar for the two organisms – Penetrate different mucous membranes columnar epithelial cells • Meningococcus—nasopharnyx • Gonococcus—fallopian tubes
Comparison of meningococcus and gonococcus Survival against host defenses Gonococcus killed in bloodstream Meningococcus grows extremely fast in bloodstream, reaching very high blood titers Reason large capsule and outer membrane proteins BIOL 533 Lecture ll
BIOL 533 6 Lecture 11 Comparison of Meningococcus and Gonococcus • Survival against host defenses – Gonococcus killed in bloodstream – Meningococcus grows extremely fast in bloodstream, reaching very high blood titers • Reason: large capsule and outer membrane proteins