Neisseria

  1. what are the common traits of neisseria
    • aerobic
    • g (-)
    • diplococci
    • oxidase (+)
    • catalase (+)
    • non motile
  2. where do non-pathogenic species of neisseria colonize
    oropharynx, nasopharynx, anogenital mucosal membrane
  3. what are the pathogenic neisseria
    • n. meningiditis (meningococci)
    • n. gonorrheae (gonococci)
  4. meningococci colonizes
    commensal in nasopharynx of healthy people
  5. can n. meningiditis grow on blood agar or chocolate agar
    • grows on blood agar
    • grows on chocolate agar
  6. is N. gonorrhoeae part of the normal healthy microbiome?
    no
  7. can gonococci grow on blood agar or chocolate agar
    • cannot grow on blood agar
    • can grow on chocolate agar
  8. gonococci has what type of growth
    fastidious growth
  9. is gonococci an STI
    yes
  10. gonococci does/does not have a capsule
    no capsule, but has a surface charge
  11. n. meningitidis does/does not have a polysaccharide capsule
    • capsule present
    • used for serotyping
    • virulence factor
  12. pathogenic and non pathogenic strains of neisseria both have what kind of virulence factor
    pili
  13. what is clinically significant about reinfection of n. gonorrheae
    does not have a capsule, so it is non immunogenic. Therefore people can be infected with the same strain over and over again
  14. what are the types of proteins on the neisseria outer membrane
    • porin proteins: facilitates invasion, protects bacteria from immune response
    • opa protens (opacity): cell to cell signaling
    • rmp proteins (reduction modifiable): protect surface antigens on abcterial cells from recognition by bactericidal antibodies
  15. what are the types of porin proteins and what bacteria expresses them
    • PorA: expressed in N. meningiditis
    • PorB: expressed in N. Gonorrheae and N. meningiditis
  16. what type of lipid is found in neisseria bacterial surface
    • lipooligosaccharide (LOS): distinct from LPS gram (-) bacteria
    • endotoxin activity
    • coats outer membrane that are released during rapid cell growth
  17. both N. meningiditis and N. gonorrheae produce what type of enzyme
    immunoglobin (Ig) A1 protease which cleaves antibodies, inactivating them
  18. what are the virulence factors of neisseria
    • pilin
    • por proteins
    • opa protein
    • rmp protein
    • transferrin binding protein, lactoferrin binding protein, hemoglobin binding protein
    • lipooligosaccharide (LOS)
    • IgA1 protease
    • B-lactamase
  19. what is the function of transferrin binding protein
    facilitates collection of iron for bacterial metabolism
  20. what is the functo=ion of B-lactamase
    hydrolyzes b-lactam ring in antibiotics, inactivating it
  21. what causes most symptoms of gonococcal disease
    immune response when gonococcal LOS stimulates release of TNF-a from immune cells
  22. what is the reservoir for n. gonorrheae and how is it transmitted
    • found in only humans
    • asymptomatic carriers
    • sexual contact
  23. where is the primary genital infection for men and women infected with gonorrhea
    • men: in urethra, purulent discharge and dysuria
    • women: in cervix, organism cannot infect vagina, dysuria,
  24. what is gonococcemia
    infection of skin and joints with septicemia
  25. what are the clinical diseases of N.gonorrheae
    • gonorrhea
    • gonococcemia
    • perihepatitis
    • purulent conjunctivitis
    • anorectal gonorrhea
    • pharyngitis
  26. what is the pathogenesis of neisseria meningitidis
    • meningococci attach specifically to receptors on non ciliated cells
    • meningococci are internalized in phagocytic vesicles
    • LOS endotoxin causes vascular damage
  27. what is the reservoir for n. meningitidis
    only humans
  28. how is n. meningitidis transmitted by respiratory droplets
    • transmitted between people in prolonged close contact
    • respiratory contact
    • epidemic spread along meningitis belt of sub saharan africa
  29. what are the diseases caused by n. meningitidis
    • meningitis
    • meningococcemia
    • pneumonia
    • arthritis
  30. what are the meningeal signs of meningitis
    • sensitivity to light
    • brudzinski sign
    • kernig's sign
  31. what is the mortality rate of untreated and treated meningococcal induced menigitis
    • untreated: 100%
    • treated: 10%
  32. describe meningococcemia
    • septicemia with or without meningitis
    • life threatening
    • thrombosis
    • DIC
    • small skin lesions that may progress to large hemorrhagic lesions
  33. how is meningococcemia and pneumonia induced n. meningitidis treated
    antibiotic therapy
  34. what is the laboratory significance of gonococci gram stain
    • very sensitive to detect gonococcal infection in men and purulent urethritis
    • can be found inside and outside neutrophils from urethral swab
    • insensitive in detecting gonoccocal 
    • useful for purulent arthritis
    • insensitive for gonococcal skin lesions
  35. what is the laboratory significance of meningococci
    • readily detected in CSF
    • can be seen in blood in patients with overwhelming meningococcal disease
  36. what is PCR used to to detect what type of neisseria
    n. gonorrhoeae
  37. what are the complications from gonococci culture
    • gonococci die rapidly if allowed to dry or exposed to cool temperatures
    • blood culture media can be toxic to gonococci
    • grows on chocolate agar
    • grows on thayer martin
  38. what are the complications from meningococci culture
    • easily recovered than gonococci
    • specimens responsible for disseminated disease virulent and must be handled with care
  39. what is the treatment for n. gonorrhoeae
    • dual antibiotic therapy
    • no vaccine for it
    • re-infection is common
  40. n. meningiditis treatment
    • antibiotic treatment
    • two tetravalent vaccines in US
    • vaccine against meningococcal serotype A
Author
tanyalequang
ID
346515
Card Set
Neisseria
Description
clinical significance and lab findings
Updated