Neisseria meningitidis
The organism cause meningitis and is also known as meningococcal or meningococcus.
The bacteria colonies in nasopharynx
Morphology
Gram -ve, spherical or oval cocci, lens shaped.
Size; 0.6-0.8 micrometre in size
Arranged in pairs, non motile.
Characteristics
1. Don't grow in ordinary media.
2. Strict aerobic
3. Optimum temperature to grow 35-36 degree Celsius.
4. PH 7.4-7.6
5. Grow occurs on media enriched with blood or serum.
Sources and mode of Transmission
Major source of information are;
1. Carrier's
2. Active or passive smoking
Transmission of infection occurs through inhalation of respiratory droplet from Carrier or patient in early stages of disease.
Human nasopharynx is reservoir of neisseria meningitidis.
The incubation period of disease is about 3 days.
Pathogenesis
Acute fever with petechial rash.
Meningococcemia; causing meningitis
Meningitis (children and young child)
Septicemia- Spread from blood - cross brain barrier infecting meninges.
Sensitivity to bright light.
Laboratory Diagnosis
Specimen collection
Microscopic examination
Seen gram -ve, large number of pus seen.
Culture
Inoculated on blood agar or chocolate agar.
Colony morphology and gram staining
Identify colony morphology and gram staining; gram -ve, spherical shape arranged in pairs.
Biochemical test
Ferment (breakdown of glucose and maltose).
Treatment
In penicillin allergic people, cefotaxime or ceftriaxone, sulphonamide or chloramphenicol is used for treatment.
Prevention
Vaccination with polysaccharide vaccine provide protection against meningitidis.
MCV (meningococcal vaccine) is commonly used.
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