Neisseria Flashcards

1
Q

Neisseria morphology:

A

Small, Gram-negative diplococci

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2
Q

Name the general virulence factors of Neisseria species:

A

Outer membrane is composed of LPS complexed with many other antigens/proteins

Type IV pili

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3
Q

Neisseria media:

A

Chocolate agar that is enhanced with CO2, oxidase, and (glucose and maltose)

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4
Q

Neisseria oxidase test:

A

Oxidase positive

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5
Q

Name the 2 species of Neisseria that cause human disease:

A

Neisseria meningitidis

Neisseria gonorrhoeae

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6
Q

Neisseria meningitidis causes ________ and _______.

A

Neisseria meningitidis causes meningitis and sepsis

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7
Q

Neisseria gonorrhoeae causes the _________ ________ disease gonorrhea.

A

Neisseria gonorrhoeae causes the sexually transmitted disease gonorrhea.

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8
Q

Describe the 5 steps of Neisseria meningitidis pathogenicity:

A
  1. N. meningitidis invades the nasopharyngeal cavity
  2. The type IV pilus is used to selectively attach to columnar cells of the nasopharynx
  3. Bacteria multiply and form large aggregates
  4. Within a few hours, pili undergo post-translational modification in the type IV pilus, which destabilizes some of the aggregates (bacteremia) while others are endocytosed (via capsule)
  5. LPS and other bacterial products cause systemic inflammation, activation of the complement system, cell damage, sepsis, shock, and death
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9
Q

Describe 3 virulence factors specific to Neisseria meningitidis and their function.

A

Major VF: Polysaccharide capsule allows it to avoid phagocytosis

Type IV pilus and other adhesins - allows adhesion to mucosal cells (nasopharynx)

LPS and outer membrane proteins - stimulates inflammation

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10
Q

Describe Neisseria gonorrhoeae pathogenicity:

A

Infection begins when the organism adheres to genitourinary epithelium mediated by pili and other surface proteins

exhibits genetic change by altering the protein structure of pili and by switching production of adhesins on and off, thereby evading the immune response

produces an intense local and acute inflammatory reaction

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11
Q

Describe the 6 virulence factors specific to Neisseria gonorrhoeae and their function.

A

Outer membrane proteins: PPORTL

Pilin – facilitates bacterial adherence to host cells and antigenic variation

PorB – prevents phagolysozyme fusion

Opa – facilitates phase variation to switch up membrane proteins

Rmp – protects other outer membrane proteins from degradation

Transferrin – obtain iron from host cell for metabolism

LPS / LOS (endotoxin) - causes local inflammatory response and tissue damage

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12
Q

The immune response to Neisseria species requires an intact _______ system.

A

The immune response to Neisseria species requires an intact complement system.

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13
Q

How does the polysaccharide capsule boost virulence of N. meningitidis?

A

Capsule is responsible for bloodstream invasion and CNS tropism

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14
Q

Transmission of N. meningitidis:

A

Respiratory droplet transmission via close contact

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15
Q

The majority of meningococcal disease occurs in ________ and ______ ________.

A

The majority of meningococcal disease occurs in infants and young children

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16
Q

There are key outbreaks of invasive meningococcal disease among ____.

A

MSM

17
Q

There is a secondary peak in meningococcal disease among ________ and ______ ______.

A

There is a secondary peak in meningococcal disease among adolescents and young adults

18
Q

Name the 2 possible outcomes of respiratory tract colonization by N. meningitidis:

A

clinical disease or a transient carrier state

19
Q

What are the 3 primary most common outcomes of N. meningitidis?

A

Meningitis
Meningococcemia
Chronic meningococcemia

20
Q

Meningitis can occur with or without ________.

A

Meningitis can occur with or without meningococcemia (most without).

21
Q

Clinical manifestations of Meningitis:

A

Very rapid onset

Severe, fulminant, acute onset of headache, fever, neck stiffness/rigidity, altered mental status

May occur with seizures and cranial nerve deficits

22
Q

Clinical manifestations of meningococcemia:

A

Sepsis that rapidly progresses to septic shock

Petechiae on extremities, especially legs that progresses rapidly to purpuric (violaceous) hemorrhagic bullae

Can see bilateral adrenal hemorrhage (Waterhouse-Freiderichson syndrome) and acute adrenal insufficiency

Hemorrhage and disseminated intravascular coagulation

23
Q

Clinical manifestations of Chronic meningococcemia:

A

Relapsing fever, arthritis, and rash that mimics vasculitis

24
Q

Name the 3 modes of diagnosis for Neisseria meningitidis:

A

Gram stain: Gram-negative diplococci from CSF sample

Culture on enriched media

Nucleic acid amplification testing (Multiplex PCR)

25
Q

Name the 3 modes of treatment and prophylaxis for Neisseria meningitidis:

A

Preferred: ceftriaxone IV

Penicillin G: if bacteria is susceptible

Prophylaxis of close contacts: rifampin, ciprofloxacin, or single dose of ceftriaxone

26
Q

Who is eligible for vaccination against Neisseria meningitidis (Serogroups A, C, Y W135)?

A

Adolescents: everyone age 11-12, booster at age 16

Adults with certain risk factors

27
Q

Who is eligible for vaccination against Neisseria meningitidis (Serogroup B)?

A

Adolescents: consider age 16-18

Adults with certain risk factors

28
Q

Describe transmission of N. gonorrhea.

A

Mucosal transmission via genital tract, mouth, anus, and eye via direct contact

commonly sexually transmitted

29
Q

True or false: There must be direct contact for transmission of N. gonorrhea.

A

True

30
Q

Women have a ______ risk of acquiring gonorrhea infection after exposure when compared to men.

A

higher

31
Q

Describe the clinical manifestations of Primary Localized N. gonorrhea Disease.

A

Manifests as urethritis in men and cervicitis in women

Pharyngitis and proctitis (rare)

Neonatal conjunctivitis

32
Q

Describe the clinical manifestations of Secondary Disseminated N. gonorrhea Disease.

A

Gonococcemia (bloodstream invasion) and septic arthritis with characteristic purulent skin lesions

Local dissemination with epididymitis/prostatitis in men

Pelvic inflammatory disease (PID) in women

Dermatitis

Endocarditis and meningitis are very rare

33
Q

Name the 3 modes of diagnosis for N. gonorrhea :

A

Gram stain: Gram-negative diplococci from urethra, cervix, or joint fluid

Culture on enriched media

Choice Test: Nucleic acid amplification testing (Multiplex PCR)

34
Q

Name treatment for N. gonorrhea:

A

Preferred treatment is Ceftriaxone IM injection

35
Q

N. gonorrhea has wide-spread resistance to what drugs?

A

Widespread resistance to quinolones and azithromycin with increasing resistance reported to cephalosporins