Neisseriae

Question 1

Neisseria contains two important human pathogens:

Answer 1

1. Neisseria meningitidis
2. Neisseria gonorrhoeae

Question 2

The Neisseria meningitidis mainly causes

Answer 2

Meningitis
meningococcemia

Question 3

More about the Neisseriae

Answer 3

It’s a gram Negative
Kidney shaped

Question 4

has a prominent polysaccharide capsule that enhances virulence by its
antiphagocytic action.

Answer 4

meningococcus
( the capsule also is the immunogen in the vaccine )

Question 5

Meningococci are divided into at least 13 serologic groups on the
basis of

Answer 5

The antigenicity of their capsular polysaccharide

Question 6

Five serotypes cause most cases of meningitis and
meningococcemia:

Answer 6

Serotype A: leading cause of epidemic meningitis
Serotype B: accounts for most diseases ( because it’s polysaccharide is not immunogenic in humans
and therefore is not part of the vaccines )

And also C , Y , W135

Question 7

Neisseria gonorrhoeae polysaccharide capsule

Answer 7

It doesn’t have ANY

Question 8

Gonococcus has multiple serotypes based on

Answer 8

The antigenicity of its PILUS PROTEIN

Question 9

Neisseriae are oxidase-positive

Answer 9

This is an important laboratory diagnostic test in which colonies exposed to phenylenediamine turn purple or black as a result of oxidation of the reagent by the enzyme cytochrome c.

Question 10

Neisseria meningitidis transmission

Answer 10

-Human are the only natural host

-And it transmitted through the airborne droplets

• they colonize the membranes of the nasopharynx and become part of the
  transient flora of the upper respiratory tract.——-> and From the nasopharynx, the organism can enter the bloodstream and spread to specific sites, such as the meninges or joints

Question 11

Two organisms cause more than 80% of cases of bacterial meningitis in infants older
than 2 months of age:

Answer 11

Strepococcus pneumonia And Neisseria meningitidis

Question 12

Which of these organisms are most likely to cause epidemics of meningitis?

Answer 12

Group A of meningococci

Question 13

ranks second to S. pneumoniae as a cause of meningitis

Answer 13

N. meningitidis

Question 14

most common cause of meningitis in persons between the ages of 2 and 18 years.

Answer 14

N.meningitidis

Question 15

Meningococci have four important virulence factors:

Answer 15

1- polysaccharide capsule
2-Endotoxin
3-IgA protease
4-Factor H binding protien FHBP

Question 16

What factor of the meningcocci causes fever, shock, and other pathophysiologic changes?

Answer 16

EASYYYYY, Endotoxin

Question 17

What factor of the meningococci enables the organism to resist phagocytosis by
polymorphonuclear leukocytes

Answer 17

Polysaccharide capsule

Question 18

What does the immunoglobulin A (IgA) protease

Answer 18

Helps the bacteria attach to the membrane of the upper respiratory tract by cleaving secretory IgA

Question 19

is the immunogen in the vaccine against group B meningococci

Answer 19

Factor H binding protein FHBP

Question 20

The most severe form of meningococcemia is

Answer 20

Waterhouse–Friderichsen syndrome
which is characterized by:
high fever
shock
widespread purpura
disseminated intravascular coagulation
thrombocytopenia
adrenal insufficiency

Question 21

The principal laboratory procedures are:

Answer 21

smear and culture of blood and spinal fluid samples

Question 22

The differentiation between N. meningitidis and N. gonorrhoeae is made on

Answer 22

The basis of sugar fermentation
Meningcocci ferment Maltose but gonococci Do Not!
( Immunofluorescence can also be used to identify these species )

Question 23

The procedure that can assist in the rapid diagnosis of meningococcal meningitis is the
“latex agglutination test” which detects capsular polysaccharide in the spinal fluid

Answer 23

-

Question 24

What is the drug of choice for meningococcal infections?

Answer 24

Penicillin G or ceftriaxone

Question 25

The vaccines against groups A, C, Y, and W-135 meningococci contain the polysaccharide capsule as
the immunogen.

Answer 25

But The vaccine against group B meningococci contains FHBP as the main immunogen ( i have a feeling that it’s gon come sooooo )