Gram Negative Cocci

Question 1

What are characteristics of the Neisseria spp.?

Answer 1

Gram-negative cocci
Oxidase positive
Coffee bean or Kidney-shape appearance
Non-motile
Non-spore forming
Gram stain red
Primarily aerobic (with some facultative anaerobes)
Often diplococcus

Question 2

What are the 2 principal Neisseria pathogens?

Answer 2

N. gonorrhoeae
N. meningitidis
Do not survive well in the environment

Question 3

What are 4 additional Neisseria species typically associated with respiratory and intestinal tract?

Answer 3

N. lactamica
N. sicca
N. subflava
N. mucosa
These may cause infections in the immunocompromised host

Question 4

Describe Moraxella catarrhalis

Answer 4

Gram-negative
aerobic
oxidase positive
diplococcus
Respiratory tract pathogen

Question 5

What is a fastidious organism?

Answer 5

Very particular food needs

Question 6

Describe how Neisseria are identified in the lab

Answer 6

Require special media and growth conditions (temperatures)

Ability to produce acid from different sugars

Question 7

Which two gram-negative organisms appear identical on a gram stain?

Answer 7

N. meningitidis and gonorrhoeae

Question 8

What makes the serogroups for meningitidis?

Answer 8

Carbohydrates in the cell wall structure

Question 9

Examples of N. meningitidis serogroups

Answer 9

A, B, C, D, X, Y, Z, W135

B & C most common in N. America

Question 10

What are the 3 most common N. meningitidis serogroups?

Answer 10

B,C & Y

Question 11

Which N. meningitidis serogroup has been associated with endemic disease in Canada?

Answer 11

C

Sub-groups have of C have been identified and are problematic

Question 12

Where is the reservoir for N. meningitidis in the body?

Answer 12

nasopharynx

Question 13

How does N. meningitidis spread?

Answer 13

Airborne droplets
Bacteria enter the bloodstream after crossing mucous barriers
Bloodborne infection is then carried to nervous system

Question 14

Which antibiotic are most meningococci susceptible to?

Answer 14

Penicillin

Question 15

Vaccines are available for which meningitis serogroups?

Answer 15

A, B, C, Y, W-135

Question 16

Moraxella catarrhalis is a normal flora of which body part?

Answer 16

nasopharynx and oral

Typically does not represent infection of respiratory tract

Question 17

When is Moraxella catarrhalis the most prolific?

Answer 17

When a concurrent virus is present.
Can then cause infection of middle ear, sinuses, or lower respiratory tract
(systemic infections rare)

Question 18

Describe the Moraxella catarrhalis bacteria

Answer 18

Gram negative coccus

Indistinguishable from other Neisseria species

Question 19

Define meningitis

Answer 19

Inflammation of the meninges (intact brain function)

Question 20

What group of symptoms indicate meningitis?

Answer 20

headache, fever and neck stiffness (nuchal rigidity)

Question 21

The CSF profile of meningitis would show alterations in these 3 things:

Answer 21

Presence of WBCs
Protein (elevated)
Glucose (low)

Question 22

Two antibiotics typically prescribed for meningitis are:

Answer 22

ceftriaxone
vancomycin
(ampicillin - added in elderly population to cover for Listeria monocytogenes)

Question 23

What are the additional precaution requirements for meningitis?

Answer 23

Contact & droplet until 24hrs of effective antimicrobial coverage has elapsed.

Question 24

What is encephalitis?

Answer 24

inflammation of the brain parenchyma (abnormality in brain function)

Question 25

Most of the WBCs in the CSF of someone with meningitis are:

Answer 25

neutrophils

Question 26

Which Gram positive cocci is most likely to cause meningitis in a 2 DAY old?

Answer 26

Group B Streptococci (GBS)

Question 27

Which Gram negative bacilli is most likely to cause meningitis in a 2 DAY old?

Answer 27

E. coli

Question 28

Which Gram negative bacilli is most likely to cause meningitis in a 2 YEAR old?

Answer 28

Haemophilus influenzae

Question 29

CSF for meningitis showing gram-positive diplococci is most likely to be which organism?

Answer 29

Streptococcus pneumoniae

Question 30

CSF for meningitis showing gram-positive bacilli is most likely to be which organism?

Answer 30

Listeria monocytogens

Question 31

Which AP are required for meningococcal meningitis and for how long?

Answer 31

Droplet; until 24 hrs after effective treatment initiated and symptom improvement

Question 32

Describe haemophilus influenza type b meningitis

Answer 32

Uncommon in adults (due to vaccination Hib)
Usually accompanied by rash
Increased infection risk to children who are close contacts
NOT an increased risk of infection to adults who are close contacts

Question 33

Prophylaxis for haemophilus influenza type b meningitis in adults and children over 4 is:

Answer 33

Rifampin, for close contacts

Question 34

Haemophilus influenza type b meningitis is typically treated with which antibiotics?

Answer 34

ceftriaxone or cefotaxime