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بسم الله الرحمن بسم الله الرحمن الرحيمالرحيم
FAMILY:FAMILY: NEISSERIACEAENEISSERIACEAE
Prof. Khalifa Sifaw GhengheshProf. Khalifa Sifaw Ghenghesh
Genus: Genus: NeisseriaNeisseria
• G-ve, diplococci, kidney shaped
• Oxidase: +ve
Neisseria gonorrhoeaeNeisseria gonorrhoeae
1. 1. N. gonorrhoeaeN. gonorrhoeae
• Gonorrhoea
• Virulence Factors------------------------------------------------------------------------------------Factor Responsible for:------------------------------------------------------------------------------------Pili Attachment to epithelial cellOMP II (PrII)OMP I (PrI) Invasion of epithelial cellsLPS Damage to epithelial cellsIgA protease Destruction of secretory Ab------------------------------------------------------------------------------------
Clinical SignificanceClinical Significance
• Transmitted by direct, close, usually sexual
contact between individuals.• Uncomplicated gonorrhoea:
– In men: acute urethritis >purulent discharge– in women (endocervix): vaginal discharge
• asymptomatic:
• ii. Conjunctivitis (ophthalmia neonatorum): • iii. Pelvic inflamatory disease (PID):• iv. Disseminated gonococcal infection (DGI):
Laboratory DiagnosisLaboratory Diagnosis• Specimens: Transport media!!!!
– Men: Urethral samples.– Women: Uretheral, cervical and rectal specimens.
• Endocervical swab >>
• In DGI:– Blood, swabs from skin lesions, or pus aspirated from a
joint.
• In neonatal ophthalmia: Conjunctival material.
• Urine specimen:
• Gram stain
• Thayer-Martin Media: –Oxidase test
–Carbohydrate utilization
Gram-stain of urethral discharge from an infected individual, showing Gram-negative diplococci.
Neisseria gonorrhoeaeUrethral smear with gram negative
intracellular diplococci
TreatmentTreatment
• N. gonorrhoeae-lactamase
• 3rd generation cephalosporins– Ceftriaxone
• Ciprofloxacin:– resistance?
2. 2. N. meningitidisN. meningitidis
• Virulence Factors: > Capsule.
• Serological Classification:– Serogroups A, B, and C.
– Others: X, Y, Z, Z' (29E), and W-135
Gram-stain of Gram-stain of Neisseria meningitidisNeisseria meningitidis Gram-negative diplococciGram-negative diplococci
Clinical SignificanceClinical Significance
• Habitat: Oro- or naso-pharynges of asymptomatic carriers
• Transmission:
• Meningococcemia and/or meningitis >
- rash
- "Waterhouse-Friderchsen syndrome"
• Pneumonia >
Laboratory DiagnosisLaboratory Diagnosis
Specimens: >> 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...
Control Control • Chemoprophylaxis.• Vaccination.
TreatmentTreatment– PenicillinPenicillin– RifampicinRifampicin– CiprofloxacinCiprofloxacin
• Other Neisseria species:– Moraxella (Branhamella) catarrhalis
Moraxella catarrhalisMoraxella catarrhalis