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NEISSERIA
Introduction
 The
Neisseriae are G-ve diplococci
 Pathogens are:- N.meningitidis

N.gonorrhoeae
 Exacting growth requirements
 Commensals easy to grow on ordinary media
N. gonorrhoeae

Obligate parasite of human urogenital tract.
 Morphology: Gram -ve diplococci (bean shaped).
 Culture: enriched media (lysed blood or chocolate),
moist aerobic atmosphere +5-10% CO2. Temp.3537oC.
Gram stain of N.gonorrhoea
Selective media

Thayer-Martin medium contains vancomycin,
colistin, nystatin & trimethoprim.

Colonies: 48hrs incubation.
Identification
 Oxidase
+ve.
 Carbohydrate utilization: N.gonorrhoeae
produces acid from glucose only.
 Slide agglutination with specific antisera
(Phadebact test).
Pathogenicity

Causes gonorrhoea
 Arthritis,
 Septicemia,

Ophthalmia neonatorum.
Gonorrhoea

Acute pyogenic infection of urethra and (in females)
cervix.
 Acute purulent urethral , vaginal discharge , dysuria
 Asymptomatic in females
 Rectum & oropharynx may be involved.
Complications
 Prostatitis,
epididymitis , urethral stricture in
males.
 Salpingitis , infertility in females
 Septicemia
 Arthritis
 Meningitis (rare).
Diagnosis
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Specimen: urethral,cervical smears &swabs
(transport medium).
Gram film: intracellular Gram -ve diplococci
Culture: selective media
Oxidase +ve
acid production from glucose
Latex agglutination
Treatment of gonorrhoea

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One curative dose
Sens. Testing
Blind treatment: ceftriaxone, ciprofloxacin
Spectinomycin
Penicillin: resistance common.
N. meningitidis

Habitat: human nasopharynx (10-25%)
 Similar to N. gonorrhoea but less exacting ?
 Can grow in BA, Chocolate agar without selective
media from CSF ?
 Id. CHO utilization: acid from glucose & maltose.
Gram stain of Neisseria meningitis
Haemorrhagic rash
Death from Waterhouse-Friderichsen syndrome
Neck rigidity
Antigenic structure
 Polysaccharide antigens
 Three
main groups A,B,C
 Other groups Y,W135.
 Grouping: slide agglutination with specific
antisera
Pathogenicity

Meningococcal meningitis, as a spread from
nasopharynx
blood stream
meninges in
susceptible hosts.
 Direct spread to meninges
 Rash
 Adrenal haemorrhage (Waterhouse-Friderchsen
syndrome)
Meningitis
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Clinically: rapid deterioration of flu like illness
Headache, neck stiffness, +ve kerning’s sign,
fever,..…
Diagnosis: CSF + blood culture
CSF: WBC , RBCs
Gram stain: bacteria & cells
Meningitis (Continue)

Culture deposit into blood & chocolate agars and
glucose broth 7 cooked meat media
 Incubate in air + 5%CO2
 Id : sugar utilization + latex
 For partially treated meningitis: detection of bacterial
antigen by: latex agglu, CCIE.. for common
serogroups of meningitis pathogens.
Treatment

Parenteral antimicrobial
 Start blind treatment after collection of specimens
by:
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Ceftriaxone or cefotaxime
Change later according to sens. Test.
Contacts: rifampicin
Prevention: vaccination (polyvalent)
Commensal Neisseriae



N.pharyngis, N.flava, N.sicca,..
In mucous mem. Of mouth,nose, pharynx, less common in
genital tract.
Differ. From pathogenic one:

grow in ordinary media( no CO2)
 at room temp.
 rough, pigmented
 acid from a number of CHOs
Other causes of meningitis
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Bacterial causes:
Three primary pathogens:
N. meningitidis, HI, S.pneumoniae
N.menningitidis
all ages
HI
2m-5y
S.pneumoniae
all ages but more common
in adult with underlying illnesses.
Other causative bacteria (Continue)
 E.coli
& other coliforms
 Listeria
 Strept.group B
 Salmonella spp.
 Favobacteria..
 All common in neonates
Other causative bacteria (Continue
 After surgery
or trauma
 S.aureus
 S.pneumoniae
 AFB
chronic meningitis
 Spirochaetes
Other Causes
 Viral
:enterivirus, Paramyxovirus, Herpes
viruses, adenoviruses, arboviruses.
 Fungi: yeasts (Candida, cryptococcus spp.)
 Aspergillus spp.
 Mucor
Findings in CSF
Normal CSF:
 Clear
, colorless
 0-5 lymphocytes
 Sterile
 150-450 mg /l protein
 2.8-3.9mmol/l glucose
CSF in bacterial meningitis
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Turbid
500-20,000 cells mainly polys,few lymphocytes
Bacteria in Gram stain
Markedly raised protein
Reduced or absent glucose
CSF in TB meningitis
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Clear or slightly turbid
10-500 cells,mainly lymphocytes( polys early)
AFB in Z-N stain
Grow in LJ medium
Moderately raised protein
Sugar reduced
CSF in viral meningitis
 Clear
or slightly turbid
 10-500 cells mainly lymphocytes
 Stool culture, or serology +ve
 Normal or slightly raised protein
 Normal glucose
Cerebral abscess
 Clear
or slightly turbid
 Bacteria: S. milleri, Bacteroides, S.aureus.
Proteus(Causative bacteria)
 0-500 mainly polymorphs
 Often no organisms in CSF
 Normal or raised protein
 Normal glucose
Complication of meningitis
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Death ( 30% with pneumococci,10% Hi &
N.meningitidis.
Ventriculitis
hydrocephalus
Paralysis
Cerebral abscess..
Treatment of meningitis
 Depends
on age ,causal bacteria
 Urgent ,parenteral
 Ceftriaxone
 Neonates: amp+ gm (or ceftriaxone)
 Sens.testing
 Anti TB