Gram negative, non-motile, non-spore forming, diplococci; aerobic
exclusively a human parasite that attacks mucous membranes and affects skin and joints
both are aerobic, require CO2 to grow, like 30-37o C (comensals prefer 22-25o C) – oxidase positive
delicate, fragile organisms that grow on selective media (Thayer-Martin) and chocolate agar + CO2
patients lacking the Terminal Complement pathway (C5-C9) have increased susceptibility
Produce IgA protease, have LPS, but do not produce exotoxins; are/were sensitive to penicillin
Obligate human pathogens
- Neisseria meningitidis – (MgC) causes meningitis and bacteremia, a.k.a. Meningococcus
- Neisseria gonorrhea – (GC) causes gonorrhea, a.k.a. Gonococcus
- 30 other comensal species defined by their ability to ferment sugars
N. Meningitidis (MgC)
15% of people have MgC present in their nasopharynx and develop immunity to that particular strain
entry into subarachnoid space causes Meningiococcal meningitis. LPS triggers the release of IL-1 and TNF
with meningitis – very rapid onset – transmitted via respiratory droplets
childhood disease: mainly in ½ - 2 year olds (because of maternal antibodies)
Vaccine that covers the four most prevalent strains (except for type B), indicated for family members of an infected individual.
Treatment: Penicillin IV for 7 days, 3rd generation cephalosporin if resistant; Rifampin for prophylaxis of family in addition to the vaccine.
After 7 days of treatment with IV antibiotics there is no relapse, however Ig mediated reactions may occur resulting in sterile pericardial effusions.
- skin petichea resulting from emboli of rapidly growing organisms
- PMN’s loaded full of diplococci in stain of CSF
- Milky and creamy CSF
- Waterhouse-Friderichson syndrome – extensive purpura and destruction of the adrenal glands
N. Gonorrhea (GC)
The "clap" , French clapoir , slang for brothel, a sexually transmitted disease
Numerous N-methylphenylalanine type pili that bind to epithelial receptors. Pili mutate continuously and are not antigenically stable enough to function as a target for a vaccine.
OMP (outer membrane protein): OMP’s Opa and OMP-1 facilitate invasion after pili attaches
Non-sexual transmission is possible but rare (when in children think sexual abuse)
Causes dysuria and purulent discharge (smear of discharge has PMN’s and diplococci)
Chlamydia travels with GC and requires different antibiotics to treat (treat both simultaneously)
Women – 60% asymptomatic, worry about upstream. GC spreads up the fallopian tubes (salpingitis)Þ pelvic peritonitis and abscesses Þ scarring that can result in ectopic pregnancies or infertility.
Men – epididymus, prostate could be involved Þ complications. Treatment aimed at treating more than just the urethra. Symptoms, if untreated, usually disappear in 8 weeks.
DGI Disseminated Gonococcal Infection: A bi-phasic disease
- PID Pelvic Inflammatory Disease : 15-20% of women with GC. Pain, fever, cervical discharge. Other organisms get involved as damage is done.
GC ophthalmic Neonatoruim
Mom Þ infant during delivery
Silver nitrate in newborn’s eyes has significantly reduced this previously major cause of blindness.
treatment for GC is a challenge because many people are asymptomatic and because of Penicillin resistance
Small doses of intramuscular (IM) 3rd generation Cephalosporins and concurrent treatment of probable Chlamydia infection with 7 day course of Tetracycline type (or Quinones) CONDOMS to prevent!
- (1) Bacteremic phase – early, skin lesions, GC in blood and/or in anogenital site
- (2) Septic joint stage – late. GC in synovial fluid, no skin lesions. Number one cause of mono-articular arthritis in young adults. (monoarticular = one articulation = one joint)
- Asymptomatic local infection with HAU auxotrophs (Need Arginine, Hypoxanthine, and Uracil) progresses to DGI with greater frequency
N. lacamica – an upper respiratory comensal, grows at 22-25o C and produces pigmented colonies
Does not grow on Martin-Lewis agar, GC and MgC do.