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بسم اهلل الرحمن الرحيم FAMILY: NEISSERIACEAE Prof. Khalifa Sifaw Ghenghesh Genus: Neisseria • G-ve, diplococci, kidney shaped • Oxidase: +ve Neisseria gonorrhoeae 1. N. gonorrhoeae • Gonorrhoea • Virulence Factors -----------------------------------------------------------------------------------Factor Responsible for: -----------------------------------------------------------------------------------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 ------------------------------------------------------------------------------------ Clinical 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 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 gonorrhoeae Urethral smear with gram negative intracellular diplococci Treatment • N. gonorrhoeae > b-lactamase • 3rd generation cephalosporins – Ceftriaxone • Ciprofloxacin: – resistance? 2. N. meningitidis • Virulence Factors: > Capsule. • Serological Classification: – Serogroups A, B, and C. – Others: X, Y, Z, Z' (29E), and W-135 Gram-stain of Neisseria meningitidis Gram-negative diplococci Clinical Significance • Habitat: Oro- or naso-pharynges of asymptomatic carriers • Transmission: • Meningococcemia and/or meningitis > - rash - "Waterhouse-Friderchsen syndrome" • Pneumonia > Laboratory 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 • Chemoprophylaxis. • Vaccination. Treatment – Penicillin – Rifampicin – Ciprofloxacin • Other Neisseria species: – Moraxella (Branhamella) catarrhalis Moraxella catarrhalis