Neisseria Meningiditis Flashcards
Name the available vaccines for N.meningitidis
Group B protein vaccine.
Group C conjugate vaccine.
Quadrivalent vaccine ACWY
How is N. Meningiditis contracted
Through Respiratory droplets
Name the infection controls of meningiditis.
Droplets infxn control are introduced before the patient completes 24hr appropriate antibiotics therapy.
Chemoprophylaxis for close contacts 7days prior to disease
Ciprofloxacin for diff age groups, pregnant women.
Vaccination;
Group C conjugate vaccine.
Group B protein vaccine.
Quadrivalent vaccine ACWY.
What is the treatment for N. Meningiditis
Third generation cephalosporins
(Ceftriaxone )
And Ciprofloxacin.
Serotyping of capsular antigen of Meningiditis is done with?
ELISA.
Enzyme linked immunosorbent assay
What are other serotyping that can be done on Meningiditis
PCR–Polymerase chain reaction.
MLST- Multiple locus sequence typing.
Meningococcal PCR can be performed on the following except;
CSF
Plasma
Serum
EDTA blood.
Joint fluids
Tears
Tears
How many serogroups were obtained?
How many are the commonest?
13
9
List the commonest serotypes
A, B C W-135, X, Y, Z
29E, Z’
Which of the serotypes are rare
X,Y,Z,Z’,29E
Which serotype is an epidemic strain(outbreak) seen in the UK
Type B
What is the pattern of disease of serotype A
Epidemic meningitis associated with different clones
Which serotypes pattern of disease is associated with local outbreaks?
Serotype C
Which of the serotype is common amongst pligrims returning from hajj
W-135
Does all the serotypes have vaccines?
Yes aside the rare serotypes
What’s the name of the vaccine of serotype C and year of introduction
Tip; Munachi likes men
MenC,
1999..
Name of the serotype B vaccine and year of license and introduction
Meningitis B vaccine
Licensed 2013
Introduced into routine schedule;2015
Why are isolates of N meningiditis be handled in a safety cabinet
Because they are hazard to employees.
They’re grouped under hazard group 2
Name the two specimen usually collected for Meningiditis diagnosis
CSF and Blood
List the laboratory investigations done on Meningiditis
Chemical pathology;
Microscopy.
Culture
Serotyping for specific antigen.
What are the laboratory findings of CSF in chemopathology in late and early infection
In Late infection:
C.S.F with high pressure.
Appearance: Turbid.
PMN’s and protein level are elevated.
Glucose level is low.
In early infection C.S.F level may be normal
List the microscopic findings;
C.S.F findings has a higher yield than blood
It’s a gram Negative intracellular diplococci.
Methylene blue picks up scanty meningococcal
List the culture features.
It’s fastidious
Transparent.
Non pigmented.
Non-hemolytic.
Mucoid formation in capsular strains.
Circular colonies.
Oxidase positive
List the clinical manifestations of Neisseria meningiditis.
Acute cases;
meningitis.
Purulent conjunctivitis.
Septicemia.
Pericarditis.
Pneumonia
Chronic cases; Septicemia.
In a lesser percentage associated with joint and skin.
Briefly discuss the pathogenesis of Meningiditis.
They possess virulence factors that enables it cause disease and aid it’s survival in the host.
A bridge in the nasopharyngeal mucousa activates it pathogenicity.
1)Type IV pili for adherence and colonization.
2) polysaccharide capsule aids in evading phagocytosis by host immunity.
3)lipooligosaccharide does the same thing.
4) IgA protease cleaves the immunoglobulin A seen in mucosa cells.
Various secretion system helps deliver IgA protease and toxin.
The only reservoir of Meningiditis is?
Humans
20% carry it as a commensal in their throat
What’s the percentage of noncapsulated strains
50%
List the risk factors of Meningiditis
Lack of bactericidal activity.
Splenectomy
Bimodal distribution of age group; 3months-3yrs and 18yrs-23yrs
Genetic polymorphisms e.g MBL, TNFA,
FC/RIIa and PAL-1
Epidemic cerebrospinal fever was described by who? What year?
Vieusseux
1805
Who isolated N. Meningiditis from CSF and year.
Weichselbaum.
1887
In what century was meningococcal carriage described?
19th century
When was the different serotypes of Meningiditis discovered
1909
List the comparison features of n meningiditis
Capsulated.
Half moon shaped(lens shaped)
Maltose and glucose fermenter.
Has no plasmids.
Colony is circular.
Exist in both intracellular and extracellular habitat.
Habitat is nasopharynx(as a bioflora)
List the comparison features of N gonorrhoea
Noncapsulated.
Kidney shaped/concave adjacent side.
Intracellular habitat.
Possess plasmids that confer drug resistance.
Glucose fermenter.
Habitat: Genitourinary tract(cervix, vagina) rarely pharynx.
Colony is of varying shapes with irregular margins.
Which of the neisseria causes opthalmic neonatorum
N. gonorrhoea
List the microbiology of Neisseria meningiditis
Aerobic, gram negative diplococci.
Oxidase positive, grows at 37°c in chocolate and blood agar.
Glucose and maltose positive
Iist the microbiology of Neisseria gonorrhoea
Gram- aerobic diplococci.
Oxidase positive,
Grow in 37°c on blood agar and chocolate agar.
glucose +
Microbiology features of non pathogenic neisseria species.
They’re aerobic, gram negative diplococci,
Oxidase positive, grow in nutrient agar at 22°c
State the microbiology of moraxella catarrhalis
Gram Negative cocci.
Oxidase positive.
Grow on chocolate and blood agar at 37°c.
Example of anaerobic gram Negative cocci is?
Veilonella spp
Which gram negative cocci is an oral commensal
Non pathogenic neisseria species
Which gram negative cocci is a respiratory pathogen
Moraxella
Gram negative bacteria has pathogenic and non pathogenic spp..
True or false?
True
Explain how splenectomy is a risk factor of Meningiditis.
1) There’s impaired bacteria clearance; as spleen filters blood and removes bacteria from it.
2) There’s decreased antibodies response: they produce antibodies that essentially fight capsulated bacterias…e.g IgM and IgG
How is complement protein deficiency a risk factor for Meningiditis pathogenesis.
Complement proteins are group of proteins that work together to oopsonize and destroy bacteria, enhance phagocytosis.
If deficient, these are fxn are impaired.
Why is age 3months to 3years a risk factor for Meningiditis
This is because of;
Immature immune system.
Lack of specific immunity against serotypes.
Higher carriage rates in nasopharynx.
Close contact in child care settings.
Why is age 18-23yrs a risk factor for Meningiditis.
This is due to;
Increased social interactions
How does lack of bactericidal activity serve as a risk factor to Meningiditis.
Impaired phagocytosis by neutrophils and monocytes.
Impaired complement system.
