5 Flashcards
9 species Genus Neisseria
○ N lactamica ○ N cinera ○ N mucosa ○ N sicca ○ N subflava ○ N polysaccarea ○ N elongata ○ N flavescens
genus neisseria morphology
- Predominantly diplococci, some coccobacilli
genus neisseria commensals of
- Commensals of the respiratory tract (or female genital tract)
2 genus niesseria species of medical importance
Neisseria meningitidis
Neisseria gonorrhoeae
meningococcus caused by
Neisseria meningitidis
meningococcus
□ Rapidly fatal infection in previously healthy people
□ Can affect any age group
2 main symptoms of meningococcus
meningitidis and bacteraemia (one or both)
meningococcus meningitidis
® Meningitis characterised by fever, meningism (headache, neck stiffness, photophobia), and pus in the CSF
meningococcus bacteraemia
® Bacteraemia characterised by fever and rash (petechiae evolving into purpura and ecchymoses)
meningococcus adverse sequelae
® Adverse sequelae include shock, disseminated intravascular coagulation, and purpura fulminans (necrosis of skin, digits, limbs)
lab results meningococcus
□ Presence of GN diplococci in CSF or blood is strongly suggestive of meningococcal infections
□ Absence does not rule it out
® Culture should be performed and a specific PCR test is also available
neisseria meningitidis found in
□ Found in the nasopharynx of 5-15%of the healthy population
® Carriage is transmissible and a prerequisite for infection
□ Disease endemic in Australia
® Small outbreaks occur
□ Regular epidemics in africa, asia, south america
neisseria meningitidis virulence factors
□ Pathogenic strains demonstrate many virulence factors allowing them to adhere to and invade epithelial cells and invade the immune system.
neisseria meningitidis serogroups
® Meningococci are divided into serogroups based on antigenic properties of the capsules
◊ A, B, C, L, W-135, X, Y, Z
◊ Infection with one serogroup provides immunity against that same group
meningococcus vaccine
◊ Vaccination
} Congugate vaccine against serogroup C is part of the australian schedule
} Quadravalent vaccine against A, C, Y, and W-135
} Group B antigen is a poor immunogen and development of an efficious vaccine has been difficult, however a vaccine is now available in australia
