FAMILY: NEISSERIACEAE

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• FAMILY NEISSERIACEAE
• Prof. Khalifa Sifaw Ghenghesh

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Genus Neisseria

• G-ve, diplococci, kidney shaped
• Oxidase ve

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Neisseria gonorrhoeae
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1. N. gonorrhoeae

• Gonorrhoea
• Virulence Factors
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• Factor Responsible for
• --------------------------------------------------
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• Pili Attachment to epithelial cell
• OMP II (PrII)
• OMP I (PrI) Invasion of epithelial cells
• LPS Damage to epithelial cells
• IgA protease Destruction of secretory Ab
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Clinical Significance

• Transmitted by direct, close, usually sexual
• contact between individuals.
• Uncomplicated gonorrhoea
• In men acute urethritis gtpurulent discharge
• in women (endocervix) vaginal discharge
• asymptomatic
• ii. Conjunctivitis (ophthalmia neonatorum)
• iii. Pelvic inflamatory disease (PID)
• iv. Disseminated gonococcal infection (DGI)

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Laboratory Diagnosis

• Specimens Transport media!!!!
• Men Urethral samples.
• Women Uretheral, cervical and rectal specimens.
  
• Endocervical swab gtgt
• In DGI
• Blood, swabs from skin lesions, or pus aspirated
  from a joint.
• In neonatal ophthalmia Conjunctival material.
• Urine specimen

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• Gram stain
• Thayer-Martin Media
• Oxidase test
• Carbohydrate utilization

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Gram-stain of urethral discharge from an infected
individual, showing Gram-negative diplococci.
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Neisseria gonorrhoeaeUrethral smear with gram
negative intracellular diplococci
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Treatment

• N. gonorrhoeae gt b-lactamase
• 3rd generation cephalosporins
• Ceftriaxone
• Ciprofloxacin
• resistance?

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2. N. meningitidis

• Virulence Factors gt Capsule.
• Serological Classification
• Serogroups A, B, and C.
• Others X, Y, Z, Z' (29E), and W-135

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Gram-stain of Neisseria meningitidis
Gram-negative diplococci
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Clinical Significance

• Habitat Oro- or naso-pharynges of
  asymptomatic carriers
• Transmission
• Meningococcemia and/or meningitis gt
• - rash
• - "Waterhouse-Friderchsen syndrome"
• Pneumonia gt

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Laboratory Diagnosis

• Specimens gtgt Transport media !!!!!
• CSF, blood, aspirate from skin lesions or pus
  from an infected joint.
• Carriers
• Gram stain Blood agar/ TM medium
• Grouping Specific antisera.
• CSF can be examined for meningococcal
  polysaccharide antigen by latex
• agglutination, coagglutination, etc...

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• Control
• Chemoprophylaxis.
• Vaccination.
• Treatment
• Penicillin
• Rifampicin
• Ciprofloxacin

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• Other Neisseria species
• Moraxella (Branhamella) catarrhalis

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Moraxella catarrhalis