Neisseria

Question 1

Feature of meningococcus

Answer 1

Gram neg diplococci,kidney shaped, form polymers
aerobic
oxidase Positive Purple

Question 2

What gives children partial immunity against meningococcus?

Answer 2

They are colonised by n lactamica

Question 3

Culture of meningococcus

Answer 3

Grows on chocolate agar

transparent grey glistening, convex

Question 4

How can the species of meningococcus be determined?

Answer 4

Carb fermentation / utilisation test

• metabolise glucose and maltose to acid
• does NOT metabolise sucrose and lactose

Question 5

Which serogroups of meningzccus are pathogenic?

Answer 5

A, B, C, Y, W-135

Question 6

What is in the cell wall of meningococcus

Answer 6

Lipooligosaccharide ( LOS )

Question 7

List the 6 virulence factors of meningococcus

Answer 7

1 polysaccharide capsule
2 pili 
3 IgA1 protease
4 Outer membrane proteins 
5 Lipooligosaccharide
6 Iron-aquisition system

Question 8

What does LOS do

Answer 8

cytokine production + alternative complement pathways

tiggers inflammatory response

Question 9

What is the natural reservoir for meningococcus

Answer 9

Human

colonises nasopharynx

Question 10

What does meningococcus release in the blood?

Answer 10

blebs containing
LOS -> endotoxaemia
OMP
capsular polysaccharides

Question 11

Is meningococcus spread by droplet or aerosols?

Answer 11

Droplets

Question 12

Dominant serogroup in Europe and America

Answer 12

B and C

Y is most dominant in North America

Question 13

Dominant serogroup in Asia and Africa

Answer 13

A and C

Question 14

Which serogroup was responsible for the 2000 outbreak in pilgrims

Answer 14

W-135

Question 15

What is the most common infectious cause of death in children and young people up to the age of 20

Answer 15

Meningococcus

Question 16

Age group at highest risk of infection w Meningococcus

Answer 16

baby <1yr

Question 17

Which serogroup of meningococcus is most common in kids <6yrs

Answer 17

B ( for the babies)

C is more common in adolescents

Question 18

Characteristics of meningococcaemia

Answer 18

abrupt onset
petechiae
high fever, chills, hypotension, headache
bilateral haemorrhage of the adrenals - Waterhouse Friedrichsen

Question 19

What is the treatment for Meningococcal infection?

Answer 19

Benzylpenicillin
3rd gen cephalosporin
chloramphenicol

Question 20

What are the options for chemoprophylaxis in close contacts of meningococcus

Answer 20

rifampicin
ceftriaxone
ciprofloxacin

Question 21

Meningococcal polysaccharide vaccine

Answer 21

effective against A,C,Y, W135
not effective in kids under 2
has no long term memory - only lasts 3-5yrs

Question 22

Meningococcal C conjugate vaccine

Answer 22

Works in under 2yo

long term protection