1. Anatomy
    2. 1. Embryology and Development
    2. Spinal cord and Spinal nerves
    3. Meninges
    4. Cerebrum
    5. Brain stem
    6. Cerebellum
    7. Diencephalon
    8. Cranial Nerves and Related Structures
    9. Ventricular system and CSF flow
    10. Special Sense Organs
  2. Physiology
    3. 11. General Neurophysiology
    12. Brain and Higher Functions
    13. Special Sensory Systems
  3. Pathology
    4. 14. Central Nervous System Disorders
    15. CNS Tumors
    16. Eye Disorders
    17. ENT Disorders
  4. Pharmacology
    5. 18. Introduction to autonomic pharmacology
    19. Cholinergic drugs
    20. Anti-cholinergic drugs
    21. Adrenergic drugs
    22. Anti-adrenergic drugs
    23. Drugs used in Glaucoma
    24. Drugs used in the treatment of pain
    25. Alcohols
    26. Sedative Hypnotics
    27. Antipsychotics
    28. Antianxiety drugs
    29. Antidepressants
    30. Analeptic agents
    31. Local anaesthetics
    32. General anaesthetics
    33. Anti-parkinsonial drugs
    34. Drugs used to reduce appetite or In the treatment of obesity
    35. Drugs for eye diseases
  5. Microbiology
    6. 36. Neisseria meningitidis
    37. Polio virus
    38. Rabies virus
    39. Japanese B Encephalitis Virus
    40. Laboratory Diagnosis of Meningitis
  6. Biochemistry
    7. 41. Introduction
    42. Acetylcholine neurotransmission steps
    43. Snake venom
    44. Neurotransmitters
Microbiology
36. Neisseria meningitidis

1.

Define meningitis. List any three organisms causing meningitis. Write the name of media used to culture CSF sample.

[2068]

➤

2.

List the organisms causing Meningitis. Describe the laboratory diagnosis of Meningitis.

[2076, 2067, 2066, 2062, 2060]

➤

3.

Describe isolation and identification of Neisseria meningitis from CSF sample.

[2065, 2064, 2063]

➤

4.

Diagrammatically describe the morphology of Neisseria meningitis.

[2064]

➤

5.

List the etiology of meningitis.

[2063]

➤

6.

Discuss the laboratory diagnosis of bacterial meningitis.

[2062]

➤

7.

Describe the morphology, colony characteristics and biochemical properties of Neisseria meningitis.

[2061]

➤

8.

Briefly describe the morphology of meningococcus and method of its isolation from clinical materials.

[2059]

➤

9.

List the most common microorganisms causing meningitis in children.

[2058]

➤

10.

Describe the pathogenesis of Neisseria meningitis infection and the laboratory diagnosis.

[2057]

➤

11.

Describe the changes in CSF in acute bacterial meningitis.

[2053]

➤

12.

Describe laboratory diagnosis of pyogenic meningitis.

[2072]

➤

13.

Name four common bacteria that causes meningitis. Describe the laboratory diagnosis of acute pyogenic meningitis.

(5)

[2076]

➤

14.

Describe laboratory diagnosis of bacterial meningitis.

(5)

[2078]

➤

MORPHOLOGY
capsule
Capsule present (Fresh isolates from blood or spinal fluid
motility
Non-motile
spore
Non-sporing
gram-stain
Gram negative
shape
  1. Oval
  2. Diplococci
  3. Unlike Neisseria gonorrhoeae adjacent sides are flattened.
size
0.6-0.8 μm
pili
Piliated
oxygenic
Strictly aerobic
image
    ◈ data:
    ■ attributes:
    ● url: https://upload.wikimedia.org/wikipedia/commons/thumb/b/bf/Neisseria_meningitidis_Charles-Orszag_2018.png/1200px-Neisseria_meningitidis_Charles-Orszag_2018.png
    ● caption: Neisseria gonorrhoea
CLASSIFICATION
serogroups
based_on
Specificity of Capsular polysaccharide antigens
number
13 serogroups
serogroups
A, B, C, D, X, Y, Z, W135, 29E, H, I, K, L
meningococal_disease_associated_serogroups
A, B, C, X, Y and W135
serotypes
based_on
Outer Membrane Protein - A (OMP) and Lipid Polysaccharides (LPS)
number
1-20 serotypes
VIRULENCE_FACTORS
pili
Acts as adhesion factor
capsule
  1. Anti-phagocytic
  2. Principal virulence factor
lipopolysaccharide(LPS)
Endotoxin
IgA_protease
Cleaves IgA molecule
outer_membrane_protein(OMP)
protein-I
por-A
por-B
One strain possess either of them.
transferrin_binding_protein
  1. Helps iron uptake from transferrin
PATHOGENESIS
host
Humans are only natural host
source_of_infection
Contaminated droplets
reservoir_of_infection
Nasopharyngeal carriers
mode_of_transmission
Air borne
incubation_period
3 days
entry_site
Sub-arachnoid space
entry_route
hematogenous_route
mermaid
    direct_spread
    infected_site
    1. Otitis media
    2. Sinusitis
    3. Conjunctivitis
    anatomic_defects
    1. Defect in the CNS structures
    2. Congenital abnormality
    travel_along_nerve
    Peripheral sheath of olfactory nerve leading to the brain
    CLINICAL_MANIFESTATIONS
    1. Meningitis
    2. Afebrile illness
    3. Meningococcal septicaemia
    4. Non-blanching petechial or Purpuric rash
    5. Arthritis
    6. Pneumonia
      7. ◉ Waterhouse-Friderichsen_syndrome:
      ◈ characterized_by:
      1. Disseminated intravascular coagulation (DIC)
      2. Large purpuric rashes
      3. Bilateral adrenal hemorhages
      4. Shock and multiorgan failure
    LAB_DIAGNOSIS
    sample_collection
    specimen
    1. CSF
    2. Blood
    3. Synovial fluid
    4. Nasopharyngeal swab
    examination_of_CSF
    collected_by
    Lumbar puncture
    CSF_morphology
    Turbid due to large number of polymorphonuclear leucocytes
    CSF_division
    1st_portion
    Microscopy
    2nd_portion
    Biochemical_test
    3rd_portion
    Culture
    microscopy
    1. CSF is centrifuged.
    2. Centrifuged deposit is Gram stained.
      3. ◈ neisseria_meningitidis_sn:
      1. Gram negative
      2. Intracellular diplococci
    3. Leukocytes increased with 90-99% neutrophils.
    4. Supernatant is kept for detection of meningococal antigen.
    biochemical_test
    glucose
    Markedly decreased or absent
    protein
    Markedly increased
    fermentation
    Fermentation of glucose and maltose with production of acid only
    catase
    Positive
    oxidase
    Positive
    indole
    Negative
    nitrate
    Nitrate is not reduced
    culture
    fastidious
    Fastidious organism
    culture_medium
    1. Chocolate agar
    2. Blood agar
    3. Muller-Hinton starch casein hydrolysate agar
    culture_environment
    35-36°C in 5-10% CO2 and high humidity for 72 hours