بسم الله 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 FactorResponsible for: PiliAttachment to epithelial cell OMP II (PrII) OMP I (PrI)Invasion of epithelial cells LPSDamage to epithelial cells IgA proteaseDestruction 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  -lactamase 3 rd 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