Neisseria meningitidis Flashcards
What are the general characteristics of Neisseria meningitidis?
Encapsulated small, gram-negative diplococci
- Oxidase positive
- Catalase positive
- Member of the normal flora of the upper respiratory tract
- Causes life-threatening disease when invading the blood or cerebrospinal fluid
What enhances the growth of Neisseria meningitidis?
CO2 enhances growth but is not absolutely required
What is the role of pili in Neisseria meningitidis?
Pili serve for attachment and enhance virulence.
What is the significance of the capsule in Neisseria meningitidis?
The capsule contains polysaccharide with known antigenic types, and it’s highly antigenic.
How is Neisseria meningitidis transmitted?
Transmission occurs by inhalation of respiratory droplets through close contacts with infectious persons
What is the most common cause of meningitis in individuals under 20?
Neisseria meningitidis is the most common cause of meningitis in individuals under 20
What are the virulence factors of Neisseria meningitidis?
Pili-mediated colonization of nonciliated cells
- Antiphagocytic polysaccharide capsule
- Toxic effects mediated by lipooligosaccharide
How the neisseria meningitis make the disease?
It’s attached to the nasopharynx non-ciliated columnar epithelium after that it’s enter the cell and Make phagocytic vacule and triplicate in the center after that, it’s megrat into sub epithelial, and if the reach to the blood, it’s meek bacteremia
What type of immunity is related to Neisseria meningitidis infection?
Immunity is related to group-specific antipolysaccharide antibodies, which are bactericidal and facilitate phagocytosis.
What is the clinical presentation of meningitis caused by Neisseria meningitidis?
Symptoms include fever, fatigue, weakness, convulsions, thrombocytopenia, and possible DIC, and it can be fatal if not treated early.
What are the recommended steps for laboratory diagnosis of Neisseria meningitidis?
Specimen collection from various sources
- Gram stain for diplococci and PMN’s
- Culture on specific media
- Oxidase test, glucose and maltose fermentation
- No routine detection of capsular antigen in body fluids
What is the drug of choice for Neisseria meningitidis infections?
Penicillin is still the drug of choice, and resistance is very rare.
