Objective : describe the morphology and structure of Neisseria meningitidis describe the transmission and clinical features of meningitides describe the process of development of meningitides what is the diagnostic test required for Neisseria meningitidis list the other causes of meningitis and its cfc finding done by : asem shadid , college of medicine .

1. PBL 3 –POD 1
Asem shadid

2. Objective :
 describe the morphology and structure of Neisseria
meningitidis
 describe the transmission and clinical features of
meningitides
 describe the process of development of meningitides
 what is the diagnostic test required for Neisseria
meningitidis
 list the other causes of meningitis and its cfc finding

3. describe the morphology
and structure of
Neisseria meningitides :

4. • Meningitis is an acute inflammation of the protective membranes
covering the brain and spinal cord, known collectively as the
meninges.
• The meninges are the membranes that envelop the central nervous
system.
• the meninges consist of three layers:
the dura mater, the arachnoid mater, and the pia mater.
• The primary function of the meninges is to protect the central nervous
system.
• Meningitis can be life-threatening
• The inflammation may be caused by infection with viruses,
bacteria, or other microorganisms, and less commonly by certain
drugs.

7.  Capsulated Gram negative cocci in
pairs (diplococci)
 0.5 – 1 µm in size
 Kidney shaped, flat sides adjacent
 Intracellular, usually
 Non motile
 Non spore forming.
Morphology

8. • Neisseria meningitidis, often referred to as meningococcus, is a
bacterium that can cause meningitis .
• N. meningitidis is a major cause of illness and death during
childhood in industrialized countries and has been responsible for
epidemics - ‫االوبئة‬ - in Africa and in Asia.
• The bacteria are round and are often joined in pairs.
• They are Gram-negative since
they have outer and inner
membranes with a thin layer
of peptidoglycan in between.
• Pili – helps in meningeal invasion
• A pilus is a hair like found on the
surface of many bacteria..

9. describe the transmission
and clinical features of
meningitides :-

10. • Transmission
• Meningococcus is spread through the exchange of saliva and other
respiratory secretions during activities like coughing, sneezing,
kissing, and chewing on toys.
• Direct contact and air borne droplets
• Close contact with infectious person
• Incubation period – 1 to 7 days
• Incubation period is the time elapsed between exposure to a
pathogenic organism and when symptoms and signs are first
apparent.
• Although dangerous disease, not easily spread.
• 15% adults carry disease causing strains in nose and throat.

11. Clinical features
Meningitis and meningococcal septicaemia may not always be easy to detect,
in early stages the symptoms can be similar to flu.
They may develop over one or two days, but sometimes develop in a matter of
hours.
It is important to remember that symptoms do not appear in any particular
order and some may not appear at all.

13. describe the process of
development of
meningitides

14. Nasopharyngeal
Colonization
Local Invasion
Bacteremia
1
2
3

15. Meningeal Invasion Bacterial Replication
Release of bacterial
components
4 5
6

16. what is the diagnostic test
required for Neisseria
meningitidis

17. • Severe stiffness of the
hamstrings causes an
inability to straighten the
leg when the hip is flexed
to 90 degrees.
• Severe neck stiffness
causes a patient's hips
and knees to flex when
the neck is flexed.
Signs

21. list the other causes of
meningitis and its cfc
finding

22. Bacterial meningitis
• Acute bacterial meningitis usually occurs when bacteria enter the
bloodstream and migrate to the brain and spinal cord.
• A number of strains of bacteria can cause acute bacterial meningitis. The
most common include:
• Streptococcus pneumoniae (pneumococcus). This bacterium is the most
common cause of bacterial meningitis in infants, young children and
adults in the United States. There is a vaccine to help reduce the
occurrence of this infection.
• Neisseria meningitidis (meningococcus). This bacterium is another leading
cause of bacterial meningitis. Meningococcal meningitis commonly occurs
when bacteria from an upper respiratory infection enter your bloodstream.
This infection is highly contagious .
• Haemophilus influenzae (haemophilus). have greatly reduced the number
of cases of this type of meningitis.
• Listeria monocytogenes (listeria).

24. Thank you
Asem shadid