NEISSERIA!!! MICROM 442 Deck 15

Question 1

2 pathogenic species?

Answer 1

• N. gonorrhoeae
• N. meningitidis

Question 2

what GM and shapre are these? -> c’mon literally loops like a pair of balls

Answer 2

GM- diplococci, kidney bean shaped

Question 3

these are non-motile and??

Answer 3

non-sporeforming

Question 4

Fastidious, requires enriched
medium like

Answer 4

chocolate agar

Question 5

primary selective media used to culture

Answer 5

Modified Thayer Martin Agar

Question 6

fast or slow growth?

Answer 6

fast -> 24 to 48 hours

Question 7

oxidase???

Answer 7

positive

Question 8

gonococus uses which sugar?

Answer 8

glucose

Question 9

meningococcus uses what sugar?

Answer 9

theres two, maltose and glucose

Question 10

what type of spectrometer is used to identify it?

Answer 10

MALDI-TOF

Question 11

host range of pathogenic neisseria?

Answer 11

-obligate for human
-mouse for n. gonorrheae

Question 12

what about commensal nessieria species?

Answer 12

usually just stay in the pharynx

Question 13

what are the major antigens?

Answer 13

-pili
-outer membrane proteins
-lipoogliosaccharides (LOS)

Question 14

outer membrane proteins

Answer 14

Por, Opa

Question 15

LOS

Answer 15

in place of
lipopolysaccharides for other Gram-
negative bacteria

Question 16

these are masters of???

Answer 16

disguise -> immune evasion

Question 17

pili

Answer 17

• Function in initial attachment to host cells
• Variable in sequence
• Host receptors:
  -CD46 on male urogenital epithelial cells
  -CR3 on female cervical epithelium

Question 18

pili phase variation

Answer 18

transcriptional regulation

Question 19

pili antigenic variation = different sequences

Answer 19

Contains conserved regions and 6
immunodominant variable regions

Question 20

Por (OMP I) -> most abundant structural surface proteins

Answer 20

• Mediates attachment to mucosal cell surface
• Invasion of host cells by binding to
  complement receptor 3 (CR3) on cervical
  epithelial cells in women

Question 21

por (OMP I) can be used for serological classification because it has two distinct

Answer 21

structural classes -> PorA & PorB

Question 22

Opa (OMP II) expression determines?

Answer 22

colony phenotype:
opaque or transparent

Question 23

OMP II also functions in??

Answer 23

close attachment to host cells

Question 24

LOS

Answer 24

• Major role in production of inflammatory
  mediators
• Plays a role in attachment to some host cells
• Sialylated LOS – confers serum resistance and
  attenuates the inflammatory response

Question 25

male infx often causes

Answer 25

urethritis

Question 26

female infx is often

Answer 26

asymptomatic

Question 27

male genitalia pathogenesis

Answer 27

-Initial attachment via pili to urethral epithelium -Cell receptor is CD46 -Not sufficient to trigger internalization -Opa expression results in closer adhesion between gonococci and host cells -Opa receptors are varied: tissue tropism? -Internalization occurs

Question 28

pathogenesis male urthrea

Answer 28

* Gonococcus enters and multiply within epithelial cells, reach the submucosa * Triggers inflammatory response * Hematogenous spread can occur ➢ Symptomatic infection

Question 29

Pathogenesis—Female genitalia

Answer 29

* Pili and Por bind to CR3 on cervical epithelial cells * iC3b deposits on LOS, binds to CR3 * Internalization via CR3 does not trigger an inflammatory response ➢ Asymptomatic infection

Question 30

Clinical Spectrum and Manifestations

Answer 30

* Urethritis * Rectal * Pharyngeal * Cervicitis * Salpingitis * Disseminated Infection * Conjunctivitis (infants)

Question 31

Urogenital infection in Females

Answer 31

* Asymptomatic in many * Symptoms range from minimal to severe * Increased vaginal discharge due to endocervical infection * Dysuria – urethral colonization

Question 32

Salpingitis

Answer 32

* Symptoms: lower abdominal pain, abnormal menses * Can result in inflammation of fallopian tube, with scarring * Important cause of infertility, ectopic pregnancy

Question 33

Disseminated Gonococcal Infection (DGI)

Answer 33

causes minor lesions on the skin

Question 34

Predominant test for GC diagnosis

Answer 34

NAAT

Question 35

abx-R is an issue so what drug is reccomended?

Answer 35

ceftriaxone

Question 36

Neisseria meningitidis

Answer 36

* Semi-typical Gram- negative cell wall * Same as N. gonorrhoeae except that N. meningitidis has a polysaccharide capsule

Question 37

Neisseria meningitidis Antigens

Answer 37

* Major antigens are capsular polysaccharide (CPS), LOS, pili, OMP’s * N. meningitidis has fewer Opa genes, but has another similar family Opc * Antigenic diversity is due partly to interspecies genetic exchange with closely related Neisseria species

Question 38

NM capsule expression is

Answer 38

down-regulated during carriage; up-regulated during invasion into bloodstream

Question 39

Asymptomatic carriage

Answer 39

* More common in adolescents, young adults * Usually transient: 75% clear within a few months * Is primary reservoir of infection * Transmission via respiratory droplets and throat secretions (saliva or spit) * Carriage is immunizing

Question 40

NM pathogenesis

Answer 40

* Attachment to oropharynx – via pili * Most organisms remain as extracellular adherent pathogens * Dissemination from pharynx is via blood stream; invasion through blood-brain barrier

Question 41

Meningitis

Answer 41

* Seen primarily in children 6 months – 10 years * Fever, vomiting, headache, confusion

Question 42

Meningococcemia

Answer 42

Abrupt onset of illness: spiking fever, chills, arthralgias, myalgias

Question 43

Dx NM

Answer 43

* Real-time PCR for N. meningitidis most sensitive * Gram stain of CSF (85% sensitivity) * Culture from blood (50-60% sensitivity) for CSF; less commonly from skin lesions, joints

Question 44

Treatment & Vaccination

Answer 44

* Penicillin G has been drug of choice, but some resistance has been identified * IDSA now recommends ceftriaxone or cefotaxime * Adjunct steroid therapy is beneficial in children

Question 45

“New” Meningococcal Vaccines

Answer 45

* Protein-based * Bivalent vaccine (Trumenba, Pfizer) * fHbp variants * 4 Component MenB vaccine (GSK) * 3 conserved proteins mixed with OMV * Approved for use in Europe and US * GET THIS IMMUNIZATION!!!! * Some protection against gonorrhea