Lecture 9 - Neisseria

Question 1

name the neisseria species commonly associated with human disease

Answer 1

neisseria meningitidis
neisseria gonorrhoeae

Question 2

give a major difference between neisseria meningitidis and neisseria gonorrhoeae

Answer 2

meningitidis has a polysaccharide capsule and gonorrhoeae does not

Question 3

what about the 2 neisseria species makes it so difficult for the immune system to keep up?

Answer 3

their pilli are antigenically diverse

Question 4

how is neisseria meningitidis transmitted?

Answer 4

through inhalation of respiratory droplets

Question 5

how is neisseria gonorrheae transmitted?

Answer 5

sexual contact of mucosal surfaces

Question 6

what are the diseases caused by neisseria meningitidis

Answer 6

meningitis and septic shock

Question 7

what are the diseases caused by neisseria gonorrhoeae

Answer 7

urethritis, cervicitis, and pelvic inflammatory disease

Question 8

neisseria bacteria are gram _____

Answer 8

negative

Question 9

are any of the neisseria bacteria we’re studying commensal?

Answer 9

meningitis colonizes the nasopharynx, while gonorrheae is not commensal

Question 10

explain the shape of neisseria bacteria

Answer 10

gram negative, flat sided, diplococci

Question 11

neisseria are ____(aerobic, facultative, or anaerobic), oxidase _____ and most are catalse ______

Answer 11

AEROBIC, oxidase positive, and most are catalse positive

Question 12

does neisseria undergo oxidation or fermentation?

Answer 12

oxidation

Question 13

neisseria meningitis produces _____ through oxidation while neisseria gonorrhoeae produce ____ through oxidation

Answer 13

neisseria meningitidis — glucose and maltose
neisseria gonorrhoeae – glucose

Question 14

differentiate between the capsules of neisseria meningitidis and neisseria gonorrheae

Answer 14

meningitisi — has 13 serogroups of its capsule, with the most infectious being A,B,C,Y, and W135

Gonorrheae does not have a capsul

Question 15

explain the pilli of neisseria bacteria

Answer 15

composed of pilin subunits. the expression is regulated by a pil gene complex – which gives antigenic diversity
the pili regulate attachment, transfer of genetic material, and give some motility

Question 16

true or false

a mutation in neisseria bacteria gives it the ability to express antigenic diversity in its pili

Answer 16

FALSE – its not a mutation
its a normal pil gene complex

Question 17

where does neisseria meningitidis colonize

Answer 17

the nasopharynx

Question 18

neisseria competes with the host cell for WHAT and HOW

Answer 18

for iron
through transferrin, lactoferrin, and hemoglobin binding proteins

Question 19

true or false

neisseria has endotoxin activity

Answer 19

TRUE – has LOS (lipoligosaccharide)
contains the lipid A and core oligosaccharide portion of LPS
endotoxin

Question 20

explain the virulence factors that neisseria has to evade the immune system

Answer 20

igA proteases – cleave hinge region of IGA (neisseria colonizes in nasopharynx, and neisseria gonorrheae is transmitted via sexual mucosal contact)

beta lactamases to degrade penicillin and other beta lactams

Question 21

what does neisseria have that enables it to facilitate invasion into epithelial cells?

Answer 21

porin proteins
they interfere with neutrophil degranulation

Question 22

explain the pathogenesis of neisseria gonorrheae

Answer 22

attaches and penetrates host mucosal cells via their pilli and Porin B protein

multiply INTRACELLULARLY and establish infection in the sub epithelial space

promote inflammation via LOS and TNF alpha

Question 23

where does neisseria gonorrhea multiply ?

Answer 23

intracellularly

Question 24

where does neisseria gonorrhea establish the infection?

Answer 24

in the subepithelial space

Question 25

can neisseria gonorrhoeae get into the bloodstream?

Answer 25

NO – they lack a capsule and are thus engulfed by neutrophils before they reach the bloodstream

however, neisseria meningitidis is encapsulated and can get into the blood

Question 26

name the diseases caused by neisseria meningitidis

Answer 26

meningitis
septicemia
pneumonia
arthritis