Neisseria Flashcards
Presentation of N meningitidis
headache, fever, vomiting,
meningeal signs (neck stiffness, photophobia)
petechial rash
A petechial rash with meningococcemia suggests thrombocytopenia which can progress to ___
Other complications include hypotension and adrenal hemorrhage, both leading to __
A petechial rash with meningococcemia suggests thrombocytopenia which can progress to DIC
Other complications include hypotension and adrenal hemorrhage, both leading to shock
Which bug causes the rash below?
N meningitidis
Chronic meningococcemia can lead to___ (less serious N meningitidis infection)
Chronic meningococcemia can lead to arthritis/dermatitis syndrome (less serious N meningitidis infection)
Neisseria associate with (ciliated/non-ciliated) cells of the ciliated epithelial layer
Neisseria associate with non-ciliated cells of the ciliated epithelial layer
Pathogenesis of N meningitidis
passage thru mucosal epithelium (first in nasopharynx) >> survival in bloodstream >> crossing of blood brain barrier >> multiplication in subarachnoid space
Survival of N meningitidis in the bloodstream is mediated by the __ and __ from transferrin
Survival of N meningitidis in the bloodstream is mediated by the capsule (anti-phagocytic and protects from complement) and iron acquisition from transferrin
Virulence factors of Neisseria meningitidis
Polysaccharide capsule
Pili
Lipo-oligosaccharide
Factor H binding protein
N meningitidis capsule serogroups that cause disease are ___
Which ones cause disease in the developing vs developed world?
Serogroup B contributes the most to virulence because ___
A more common in developing world, B and C more common in developed countries
Type B = polysialic acid (sialic acid present on host cell membranes so this is a type of molecular mimicry)
What is the function of Pili in N meningitidis?
Attachement to resp epithelium (also binds CD46 - complement regulatory protein)
Role of LOS in N meningitidis
Potent endotoxin (mediates inflammatory response)
Dx of Neisseria meningitidis
Gram stain of CSF specimen
culture from blood or CSF specimen
Rx of N meningitidis
Prophylaxis for close contacts?
Ceftriaxone (no more penicillin b/c resistance)
3rd generation cephalosporins (remember the meningitis space helmet on general Taz’s head in Sketchy. One to know: ceftriaxone (3 axes))
Rifampin (#rifampin rifle)
Neisserica vaccine types: (describe what they’re made of)
Menomune (MSPV4)
Menactra (MCV4)
Menjugate
MPSV4 or Menomune - A, C, Y, W135 serotypes
MCV4 or Menactra - A, C, Y, W135 conjugated to diphtheria toxoid
Menjugate - C conjugated to diphtheria toxoid
New vaccines for serogroup B: (what’s in them)
Bexsero
Trumenba
Bexsero has 3 Neisserial antigens + outer membrane protein vesicles
Trumenba has 2 factor H binding protein variants
__ is a gram neg coccobacillus member of the Neisseria family that causes infectious arthritisin children (normal oropharyngeal flora, esp in kids)
Kingella kingae
Dx of Kingella
Rx of Kingella infection
Dx: blood culture vials (grows poorly on agar)
Rx: Ampicillin or Ceftriaxone
N gonorrhoeae presentation in males
Urethritis: purulent urethral discharge and dysuria
N gonorrhoeae presentation in females
cervical/vaginal discharge; dysuria and abdominal pain
ascending infection leading to salpingitis (infection of fallopian tubes), ovarian abscesses, and pelvic inflammatory disease
Other infections ass’d with Neisseria include __ (affects musculoskeletal system) and ___ (affects babies born to infected moms)
Arthritis
Conjunctivitis
N gonorrhoeae pathogenesis
Bug initially adheres to the epithelial cells of the UG tract >> intimate attachment >> invasion of cells
Doesn’t go into bloodstream generally, and doesn’t cross blood brain barrier
Bug also enters and LIVES INSIDE neutrophils (PMNs) hence ass’n with WBCs
N gonorrheae virulence factors
Pili - promote adherence to epithelial cells (PilE – major subunit of the pilus; PilC – adhesion on the tip of the pilus)
Opa (PII) - adherence to epithelial cells and neutrophils; suppresses lymphocyte functions
LOS - binds to asialoglycoprotein receptor on sperm and urethral epithelium
Iron binding proteins
Mechanisms of protection from immune response of N gonorrhea
Antigenic and phase variation
(alter pili proteins/express different variations; sialylation of LOS mediated by gonococcal sialyltransferase (Lst) using host serum component)
Rx for N gonorrheae
Ceftriaxone + azithromycin (assume co-infection with Chlamydia)
Mechanism of N gonorrheae drug resistance
Efflux pump
