Gram Negative Cocci

Question 1

Neisseria pathogen species

Answer 1

N. Meningitidis
N. Gonorrhoeae

Question 2

Characteristics of Neisseria

Answer 2

• obligate aerobe
• non motile
• non spore forming
• catalase & oxidase positive

Question 3

Medium for neisseria

Answer 3

Chocolate agar

Question 4

Virulence factors of N. Gonorrhoeae

Answer 4

• pili
• lipooligosaccharide
• outer membrane proteins (Por, omp, Rmp)
• IgA protease
• beta lactamase

Question 5

Differentiation of N. Gonorrhoeae and N. Meningitidis

Answer 5

N. G -> ferments only glucose
N. M -> ferments Glucose & Maltose

Question 6

Serogroups and Serotypes of N. Meningitidis

Answer 6

Serogroups (13) defined by Polysaccharide capsule
Serotypes (20) defined by OMP

Question 7

Microscopic appearance on gram stain of neisseria and moraxella

Answer 7

Kidney or bean shaped gram negative diplococci
Often within polymorphonuclear neutrophils in smears from clinical samples

Question 8

How to distinguish neisseria from moraxella

Answer 8

Both are oxidase positive but only moraxella has DNase activity

Question 9

Answer 9

DNase test